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10-bit digital temperature sensor (ad7416) and four single-channel adcs ad7416/ad7417/ad7418 rev. i information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. specifications subject to change without notice. no license is granted by implication or otherwise under any patent or patent rights of analog devices. trademarks and registered trademarks are the property of their respective owners. one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781.329.4700 www.analog.com fax: 781.461.3113 ?1998C2010 analog devices, inc. all rights reserved. features 10-bit adc with 15 s and 30 s conversion times single and 4 single-ended analog input channels on-chip temperature sensor: ?40c to +125c on-chip track-and-hold overtemperature indicator automatic power-down at the end of a conversion wide operating supply range: 2.7 v to 5.5 v i 2 c-compatible serial interface selectable serial bus address allows connection of up to 8 ad7416/ad7417 devices to a single bus ad7416 is a superior replacement for lm75 applications data acquisition with ambient temperature monitoring industrial process control automotive battery-charging applications personal computers general description the ad7417 and ad7418 are 10-bit, 4-channel and single-channel adcs with an on-chip temperature sensor that can operate from a single 2.7 v to 5.5 v power supply. the devices contain a 15 s successive approximation converter, a 5-channel multiplexer, a temperature sensor, a clock oscillator, a track-and-hold, and a reference (2.5 v). the ad7416 is a temperature-monitoring only device in an 8-lead package. the temperature sensor on the parts can be accessed via multip- lexer channel 0. when channel 0 is selected and a conversion is initiated, the resulting adc code at the end of the conversion gives a measurement of the ambient temperature (1c @ 25c). on-chip registers can be programmed with high and low tempera- ture limits, and an open-drain overtemperature indicator (oti) output is provided, which becomes active when a programmed limit is exceeded. a configuration register allows programming of the sense of the oti output (active high or active low) and its operating mode (comparator or interrupt). a programmable fault queue counter allows the number of out-of-limit measurements that must occur before triggering the oti output to be set to prevent spurious triggering of the oti output in noisy environments. functional block diagrams setpoint comparator 10-bit analog-to-digital converter ad7416 band gap temperature sensor address pointer register temperature value register configuration register serial bus interface fault queue counter t oti setpoint register t hyst setpoint register 7 2 1 4 3 8 6 5 a0 gnd oti v dd sda scl a1 a2 01126-001 figure 1. ad7416 ad7417 13 2 3 4 5 12 11 a0 1 nc nc = no connect 16 nc 6 gnd 15 convst temp sensor mux ref 2.5v sampling capacitor clock t oti setpoint register a > b b data out i 2 c interface a control logic a in1 8 a in2 9 a in3 10 a in4 v balance oti ref in 14 v dd scl sda a1 a2 01126-002 7 charge distribution dac figure 2. ad7417 ad7418 1 2 3 6 4 gnd 8 convst temp sensor mux ref 2.5v sampling capacitor clock t oti setpoint register a > b b data out i 2 c interface a control logic a in v balance oti ref in 7 v dd scl sda 01126-003 5 charge distribution dac figure 3. ad7418
ad7416/ad7417/ad7418 rev. i | page 2 of 24 table of contents features .............................................................................................. 1 ? applications....................................................................................... 1 ? general description ......................................................................... 1 ? functional block diagrams............................................................. 1 ? revision history ............................................................................... 2 ? product highlights ........................................................................... 3 ? specifications..................................................................................... 4 ? ad7417/ad7418 specifications................................................. 4 ? ad7416 specifications................................................................. 6 ? absolute maximum ratings............................................................ 7 ? esd caution.................................................................................. 7 ? pin configurations and function descriptions ........................... 8 ? terminology .................................................................................... 10 ? theory of operation ...................................................................... 11 ? circuit information.................................................................... 11 ? converter details........................................................................ 11 ? typical connecti on diagram ................................................... 11 ? analog inputs.............................................................................. 11 ? on-chip reference .................................................................... 11 ? temperature measurement ....................................................... 12 ? internal register structure........................................................ 12 ? serial bus interface..................................................................... 14 ? oti output ................................................................................. 17 ? fault queue ................................................................................. 17 ? power-on defaults..................................................................... 17 ? operating modes........................................................................ 17 ? convst start mode................................................................. 18 ? applications information .............................................................. 19 ? supply decoupling ..................................................................... 19 ? power-on reset.......................................................................... 19 ? mounting the ad7416/ad7417/ad7418 .............................. 19 ? fan controller............................................................................. 19 ? thermostat .................................................................................. 19 ? system with multiple ad7416 devices................................... 20 ? outline dimensions ....................................................................... 21 ? ordering guide .......................................................................... 23 ? revision history 11/10rev. h to rev. i changes to figure 19...................................................................... 16 2/09rev. g to rev. h updated format..................................................................universal changes to data sheet title, figure 2 and figure 3..................... 1 moved product highlights section................................................ 3 changes to table 1............................................................................ 4 changes to endnote 1, table 2........................................................ 6 added figure 5 caption................................................................... 7 changes to table 4............................................................................ 8 changes to table 5 and table 6....................................................... 9 changes to on-chip reference section...................................... 11 changes to figure 13...................................................................... 12 changes to table 8 and table 10................................................... 13 changes to figure 15, figure 16, and figure 17 ......................... 15 changes to reading data from the ad7416/ad7417/ad7418 section, figure 18, and figure 19 ................................................. 16 change to mode 1 .......................................................................... 17 changes to figure 22 caption and convst pin mode section.............................................................................................. 18 moved figure 21 and figure 22 .................................................... 18 changes to power-on reset section............................................ 19 updated outline dimensions ....................................................... 21 changes to ordering guide .......................................................... 23 8/04data sheet changed from rev. f to rev. g changes to figure 12...................................................................... 12 changes to reading data from the ad7416/ad7417/ad7418 section.............................................................................................. 13 changes to power-on-reset section ........................................... 14 7/03data sheet changed from rev. e to rev. f updated features...............................................................................1 updated specifications .....................................................................3 updated absolute maximum ratings ............................................6 updated ordering guide .................................................................6 updated product highlights............................................................7 updated circuit information...........................................................7 updated temperature measurement section ................................9 10/02data sheet changed from rev. d to rev. e edits to specifications headings .....................................................2 added temperature measurement section....................................8 edits to serial bus address section .............................................. 10 edits to figure 11............................................................................ 12 edits to convst pin mode section ........................................... 14 edits to power-on-reset section ................................................. 14 addition of figures 16 and 17 ...................................................... 15 updated outlines ........................................................................... 16
ad7416/ad7417/ad7418 rev. i | page 3 of 24 an i 2 c? compatible serial interface allows the ad7416/ad7417/ ad7418 registers to be written to and read back. the three lsbs of the ad7416/ad7417 serial bus address can be selected, which allows up to eight ad7416/ad7417 devices to be connected to a single bus. the ad7417 is available in a narrow body, 0.15 inch, 16-lead, small outline package (soic) and in a 16-lead, thin shrink, small outline package (tssop). the ad7416 and ad7418 are available in 8-lead soic and msop packages. product highlights 1. the ad7416/ad7417/ad7418 have an on-chip temperature sensor that allows an accurate measurement of the ambient temperature (1c @ 25c, 2c overtemperature) to be made. the measurable temperature range is ?40c to +125c. an overtemperature indicator is implemented by carrying out a digital comparison of the adc code for channel 0 (temperature sensor) with the contents of the on-chip t oti setpoint register. 2. the ad7417 offers a space-saving, 10-bit analog-to-digital solution with four external voltage input channels, an on- chip temperature sensor, an on-chip reference, and a clock oscillator. 3. the automatic power-down feature enables the ad7416/ ad7417/ad7418 to achieve superior power performance. at slower throughput rates, the part can be programmed to operate in a low power shutdown mode, allowing further savings in power consumption.
ad7416/ad7417/ad7418 rev. i | page 4 of 24 specifications ad7417/ad7418 specifications v dd = 2.7 v to 5.5 v, gnd = 0 v, ref in = 2.5 v, unless otherwise noted. table 1. parameter a version b version 1 unit test conditions/comments dc accuracy any channel resolution 10 10 bits minimum resolution for which no missing codes are guaranteed 10 10 bits relative accuracy 2 1 1 lsb max this specification is typical for v dd of 3.6 v to 5.5 v differential nonlinearity 2 1 1 lsb max this specification is typical for v dd of 3.6 v to 5.5 v gain error 2 3 3 lsb max external reference 10 10 lsb max internal reference gain error match 2 0.6 0.6 lsb max ad7417 only offset error 2 4 4 lsb max offset error match 2 0.7 0.7 lsb max ad7417 only analog inputs input voltage range vref vref v max 0 0 v min input leakage current 3 1 1 a max input capacitance 10 10 pf max temperature sensor 1 measurement error ambient temperature 25c 2 1 c max t min to t max 3 2 c max temperature resolution 1/4 1/4 c/lsb conversion rate track-and-hold acquisition time 4 400 400 ns max source impedance < 10 conversion time temperature sensor 30 30 s max typically 27 s channel 1 to channel 4 15 15 s max typically 10 s reference input 5 , 6 ref in input voltage range 2.625 2.625 v max 2.5 v + 5% 2.375 2.375 v min 2.5 v ? 5% input impedance 40 40 k min input capacitance 10 10 pf max on-chip reference nominal 2.5 v reference error 6 25 25 mv max temperature coefficient 6 80 80 ppm/c typ digital inputs input high voltage, v ih v dd 0.7 v dd 0.7 v min input low voltage, v il v dd 0.3 v dd 0.3 v max input leakage current 1 1 a max digital outputs output low voltage, v ol 0.4 0.4 v max i ol = 3 ma output high current 1 1 a max v oh = 5 v
ad7416/ad7417/ad7418 rev. i | page 5 of 24 parameter a version b version 1 unit test conditions/comments power requirements v dd 5.5 5.5 v max for specified performance 2.7 2.7 v min i dd logic inputs = 0 v or v dd normal operation 600 600 a max power-down 1.5 1.5 a max 0.7 a typically auto power-down mode v dd = 3 v; see the operating modes section 10 sps throughput rate 6 6 w typ 1 ksps throughput rate 60 60 w typ 10 ksps throughput rate 600 600 w typ power-down 3 3 w max typically 0.15 w 1 b version applies to ad7417 only with temper ature range of ?40c to +85 c. a version temperature rang e is ?40c to +125c. for v dd = 2.7 v, t a = 85c maximum and temperature sensor measurem ent error = 3c maximum. 2 see the terminology section. 3 refers to the input current when the part is not converting. primarily due to revers e leakage current in the esd protection di odes. 4 sample tested during initial releas e and after any redesign or process change that may affect this parameter. 5 on-chip reference shuts down when an external reference is applied. 6 the accuracy of the temperature sensor is affected by reference tolerance.
ad7416/ad7417/ad7418 rev. i | page 6 of 24 ad7416 specifications v dd = 2.7 v to 5.5 v, gnd = 0 v, ref in = 2.5 v, unless otherwise noted. table 2. parameter min typ max unit test conditions/comments temperature sensor and adc accuracy 2.0 c t a = ?25c to + 100c ( v dd = 3 v minimum) 1 3.0 c t a = ?40c to + 125c ( v dd = 3 v minimum) 1 resolution 10 bits temperature conversion time 40 s update rate, t r 400 s oti delay 1 t r 6 t r ms depends on fault queue setting supply current 1.0 ma i 2 c active 350 600 a i 2 c inactive 0.2 1.5 a shutdown mode t oti default temperature 80 c t hyst default temperature 75 c digital inputs input high voltage, v ih v dd 0.7 v dd + 0.5 v input low voltage, v il ?0.3 v dd 0.3 v input high current, i ih +0.005 +1.0 a v in = 5 v input low current, i il ?0.005 ?1.0 a v in = 0 v input capacitance, c in 20 pf all digital inputs digital outputs output low voltage, v ol 0.4 v i ol = 3 ma output high current 1 a v oh = 5 v output fall time, t f 250 ns c l = 400 pf, i o = 3 ma os output low voltage, v ol 0.8 v i out = 4 ma ac electrical characteristics 2 ad7416/ad7417/ad7418 serial clock period, t 1 2.5 s see figure 4 data in setup time to scl high, t 2 50 ns see figure 4 data out stable after scl low, t 3 0 ns see figure 4 sda low setup time to scl low (start condition), t 4 50 ns see figure 4 sda high hold time after scl high (stop condition), t 5 50 ns see figure 4 sda and scl fall time, t 6 300 ns see figure 4 1 for v dd = 2.7 v to 3 v, t a maximum = 85c and temperature sens or measurement erro r = 3c maximum. 2 sample tested during initial releas e and after any redesign or process change that may affect this parameter. scl t 1 t 4 t 2 t 5 t 3 t 6 sda data in sda data out 01126-004 figure 4. diagram for serial bus timing
ad7416/ad7417/ad7418 rev. i | page 7 of 24 absolute maximum ratings t a = 25c, unless otherwise noted. table 3. parameter rating v dd to agnd ?0.3 v to +7 v v dd to dgnd ?0.3 v to +7 v analog input voltage to agnd a in1 to a in4 ?0.3 v to v dd + 0.3 v reference input voltage to agnd 1 ?0.3 v to v dd + 0.3 v digital input voltage to dgnd ?0.3 v to v dd + 0.3 v digital output voltage to dgnd ?0.3 v to v dd + 0.3 v operating temperature range a version ?40c to +125c b version ?40c to +85c storage temperature range ?65c to +150c junction temperature 150c tssop, power dissipation 450 mw ja thermal impedance 120c/w lead temperature, soldering 260c vapor phase (60 sec) 215c infrared (15 sec) 220c 16-lead soic package, power dissipation 450 mw ja thermal impedance 100c/w lead temperature, soldering vapor phase (60 sec) 215c infrared (15 sec) 220c 8-lead soic package, power dissipation 450 mw ja thermal impedance 157c/w lead temperature, soldering vapor phase (60 sec) 215c infrared (15 sec) 220c msop package, power dissipation 450 mw ja thermal impedance 206c/w lead temperature, soldering vapor phase (60 sec) 215c infrared (15 sec) 220c 1 if the reference input voltage is likely to exceed v dd by more than 0.3 v (for example, during power-up) and the refe rence is capable of supplying 30 ma or more, it is recommended to us e a clamping diode between the ref in pin and the v dd pin. figure 5 shows how the diode should be connected. stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. ref in bat81 ad7417 v dd 01126-025 figure 5. diode connection esd caution
ad7416/ad7417/ad7418 rev. i | page 8 of 24 pin configurations and function descriptions nc 1 sda 2 scl 3 oti 4 nc 16 convst 15 v dd 14 a0 13 ref in 5 a1 12 gnd 6 a2 11 a in1 7 a in4 10 a in2 8 a in3 9 nc = no connect ad7417 top view (not to scale) 01126-005 figure 6. ad7417 pin configuration (soic/tssop) table 4. ad7417 pin function descriptions pin no. mnemonic description 1, 16 nc no connection. do not connect anything to this pin. 2 sda digital i/o. serial bus bidirectional data. push-pull output. 3 scl digital input. serial bus clock. 4 oti this pin is a logic output. the overtemperature indicator (o ti) is set if the result of a conversion on channel 0 (temperature sensor) is greater than an 8-bit word in the t oti setpoint register. the signal is reset at the end of a serial read operation. open-drain output. 5 ref in reference input. an external 2.5 v reference can be connected to the ad7417 at this pin. to enable the on-chip reference, the ref in pin should be tied to gnd. if an external reference is connected to the ad7417, the internal reference shuts down. 6 gnd ground reference for track-and-hold, compar ator and capacitor dac, and digital circuitry. 7 to 10 a in1 to a in4 analog input channels. the ad7417 has four analog inp ut channels. the input channels are single-ended with respect to gnd. the input channels can convert voltage signals in the range of 0 v to vref. a channel is selected by writing to the configuration register of the ad7417. 11 a2 digital input. this is the highest programmable bit of the serial bus address. 12 a1 digital input. this is the middle pr ogrammable bit of the serial bus address. 13 a0 digital input. this is the lowest programmable bit of the serial bus address. 14 v dd positive supply voltage, 2.7 v to 5.5 v. 15 convst logic input signal. convert start signal. the rising edge of this signal fully powers up the part. the power-up time for the part is 4 s. if the convst pulse is greater than 4 s, the falling edge of convst places the track-and-hold mode into hold mode and initiates a conversion. if the pulse is less than 4 s, an internal timer ensures that the track-and-hold does not go into hold, and conversion is not initiated until the power-up time has elapsed. the track-and-hold goes into track mode again at the end of conversion (see the section). operating modes
ad7416/ad7417/ad7418 rev. i | page 9 of 24 sda 1 scl 2 oti 3 gnd 4 v dd 8 a0 7 a1 6 a2 5 ad7416 top view (not to scale) 0 1126-006 sda 1 scl 2 oti 3 gnd 4 convst 8 v dd 7 ref in 6 a in 5 ad7418 top view (not to scale) 01126-007 figure 7. ad7416 pin configurat ion (soic/msop) figure 8. ad7418 pin configuration (soic/msop) table 5. ad7416 pin function descriptions pin no. mnemonic description 1 sda digital i/o. serial bus bidirectional data. push-pull output. 2 scl digital input. serial bus clock. 3 oti this pin is a logic output. the oti is set if the result of a conversion on channel 0 (temperature sensor) is greater than an 8-bit word in the t oti setpoint register. the signal is reset at the end of a serial read operation. open-drain output. 4 gnd ground reference for track-and-hold, compar ator and capacitor dac, and digital circuitry. 5 a2 digital input. this is the highest programmable bit of the serial bus address. 6 a1 digital input. this is the middle pr ogrammable bit of the serial bus address. 7 a0 digital input. this is the lowest programmable bit of the serial bus address. 8 v dd positive supply voltage, 2.7 v to 5.5 v. table 6. ad7418 pin function descriptions pin no. mnemonic description 1 sda digital i/o. serial bus bidirectional data. push-pull output. 2 scl digital input. serial bus clock. 3 oti this is a logic output. the oti is set if the result of a conversion on channel 0 (temperature sensor) is greater than an 8-bit word in the t oti setpoint register. the signal is reset at the end of a serial read operation. open-drain output. 4 gnd ground reference for track-and-hold, compar ator and capacitor dac, and digital circuitry. 5 a in analog input channel. the input channel is single-ended with respect to gnd. the input channel can convert voltage signals in the range of 0 v to vref. the analog in put channel is selected by writing to the configuration register of the ad7418 and choosing channel 4. 6 ref in reference input. an external 2.5 v reference can be connected to the ad7418 at this pin. to enable the on-chip reference, the ref in pin should be tied to gnd. if an external reference is connected to the ad7418, the internal reference shuts down. 7 v dd positive supply voltage, 2.7 v to 5.5 v. 8 convst logic input signal. convert start signal. the rising edge of this signal fully powers up the part. the power-up time for the part is 4 s. if the convst pulse is greater than 4 s, the falling edge of convst places the track-and-hold mode into hold mode and initiates a conversion. if the pulse is less than 4 s, an internal timer ensures that the track-and-hold does not go into hold, and conversion is not initiated until the power-up time has elapsed. the track-and-hold goes into track mode again at the end of conversion (see the section). operating modes
ad7416/ad7417/ad7418 rev. i | page 10 of 24 terminology relative accuracy relative accuracy or endpoint nonlinearity is the maximum deviation from a straight line passing through the endpoints of the adc transfer function. differential nonlinearity this is the difference between the measured and the ideal 1 lsb change between any two adjacent codes in the adc. offset error this is the deviation of the first code transition (0000000) to (0000001) from the ideal, that is, gnd + 1 lsb. offset error match this is the difference in offset error between any two channels. gain error this is the deviation of the last code transition (1111110) to (1111111) from the ideal, that is, vref ? 1 lsb, after the offset error has been adjusted out. gain error match this is the difference in gain error between any two channels. track-and-hold acquisition time track-and-hold acquisition time is the time required for the output of the track-and-hold amplifier to reach its final value, within ? lsb, after the end of conversion (the point at which the track-and-hold returns to track mode). it also applies to situations where a change in the selected input channel takes place or where there is a step input change on the input voltage applied to the selected a in input of the ad7417 or ad7418. it means that the user must wait for the duration of the track-and- hold acquisition time after the end of conversion, or after a channel change or step input change to a in before starting another conversion, to ensure that the part operates to specification.
ad7416/ad7417/ad7418 rev. i | page 11 of 24 theory of operation circuit information the ad7417 and ad7418 are single-channel and four-channel, 15 s conversion time, 10-bit adcs with on-chip temperature sensor, reference, and serial interface logic functions on a single chip. the ad7416 has no analog input channel and is intended for temperature measurement only. the adc section consists of a conventional successive approximation converter based around a capacitor dac. the ad7416, ad7417, and ad7418 are capable of running on a 2.7 v to 5.5 v power supply, and the ad7417 and ad7418 accept an analog input range of 0 v to +vref. the on-chip temperature sensor allows an accurate measurement of the ambient device temperature to be made. the working measurement range of the temperature sensor is ?40c to +125c. the parts require a 2.5 v reference that can be provided from the parts own internal reference or from an external reference source. converter details conversion is initiated on the ad7417/ad7418 by pulsing the convst input. the conversion clock for the part is internally generated so that no external clock is required except when reading from and writing to the serial port. the on-chip track- and-hold goes from track mode to hold mode, and the conversion sequence is started on the falling edge of the convst signal. a conversion is also initiated in the automatic conversion mode every time a read or write operation to the ad7416/ad7417/ ad7418 takes place. in this case, the internal clock oscillator (which runs the automatic conversion sequence) is restarted at the end of the read or write operation. the track-and-hold goes into hold mode approximately 3 s after the read or write operation is complete, and a conversion is then initiated. the result of the conversion is available either 15 s or 30 s later, depending on whether an analog input channel or the tempera- ture sensor is selected. the track-and-hold acquisition time of the ad7417/ad7418 is 400 ns. a temperature measurement is made by selecting the channel 0 of the on-chip mux and carrying out a conversion on this channel. a conversion on channel 0 takes 30 s to complete. temperature measurement is explained in the temperature measurement section. the on-chip reference is not available to the user, but ref in can be overdriven by an external reference source (2.5 v only). all unused analog inputs should be tied to a voltage within the nominal analog input range to avoid noise pickup. for minimum power consumption, the unused analog inputs should be tied to gnd. typical connection diagram figure 9 shows a typical connection diagram for the ad7417. using the a0, a1, and a2 pins allows the user to select from up to eight ad7417 devices on the same serial bus, if desired. an external 2.5 v reference can be connected at the ref in pin. if an external reference is used, a 10 f capacitor should be connected between ref in and gnd. sda and scl form the 2-wire i 2 c compatible interface. for applications where power consump- tion is of concern, the automatic power-down at the end of a conversion should be used to improve power performance (see the operating modes section.) + + supply 2.7v to 5.5v 2-wire serial interface 0.1f 10f 10f for external reference optional external reference ad780/ ref192 0v to 2.5v input sda scl gnd oti convst v dd ref in ad7417 a0 a1 a2 a in1 a in2 a in3 a in4 01126-008 microcontroller/ microprocessor figure 9. typical ad7417 connection diagram analog inputs figure 10 shows an equivalent circuit of the analog input structure of the ad7417 and ad7418. the two diodes, d1 and d2, provide esd protection for the analog inputs. care must be taken to ensure that the analog input signal never exceeds the supply rails by more than 200 mv to prevent these diodes from becoming forward-biased and start conducting current into the substrate. the maximum current these diodes can conduct without causing irreversible damage to the part is 20 ma. capacitor c2 in figure 10 is typically about 4 pf and can primarily be attributed to pin capacitance. resistor r1 is a lumped component made up of the on resistance of a multiplexer and a switch. this resistor is typically about 1 k. capacitor c1 is the adc sampling capacitor and has a capacitance of 3 pf. v dd v balance a in r1 1k ? convert phase: switch open track phase: switch closed d1 d2 c2 4pf c1 3pf 01126-009 figure 10. equivalent analog input circuit on-chip reference the ad7417/ad7418 have an on-chip 1.2 v band gap reference that is amplified by a switched capacitor amplifier to give an output of 2.5 v. the amplifier is only powered up at the start of the conversion phase and is powered down at the end of the conversion. the on-chip reference is selected by connecting the ref in pin to analog ground, which causes sw1 (see figure 11 ) to open and the reference amplifier to power up during a conver- sion. therefore, the on-chip reference is not available externally.
ad7416/ad7417/ad7418 rev. i | page 12 of 24 an external 2.5 v reference can be connected to the ref in pin. this has the effect of shutting down the on-chip reference circuitry. ref in sw1 26k? 2.5v 24k? 1.2v 1.2v external reference detect buffer 0 1126-010 figure 11. on-chip reference temperature measurement a common method of measuring temperature is to exploit the negative temperature coefficient of a diode, or the base-emitter voltage of a transistor, operated at a constant current. unfortu- nately, this technique requires calibration to null out the effect of the absolute value of v be , which varies from device to device. the technique used in the ad7416/ad7417/ad7418 is to measure the current change in v be when the device is operated at two different currents. this is given by () nqktv be n1/ = where: k is boltzmanns constant. q is the charge on the electron (1.6 10 ?19 coulombs). t is the absolute temperature in kelvins. n is the ratio of the two currents. sensing transistor to adc sensing transistor v out+ v dd v out? in i 01126-011 figure 12. temperature measurement technique figure 12 shows the method the ad7416/ad7417/ad7418 use to measure the device temperature. to measure v be , the sensor (substrate transistor) is switched between operating currents of i and n i. the resulting waveform is passed through a chopper-stabilized amplifier that performs the functions of amplification and rectification of the waveform to produce a dc voltage proportional to v be . this voltage is measured by the adc to give a temperature output in 10-bit twos complement form. the temperature resolution of the adc is 0.25c, which corres- ponds to 1 lsb of the adc. the adc can theoretically measure a temperature span of 255c; the guaranteed temperature range is ?40c to +125c. the result of th e conversion is stored in the temperature value register (0x00) as a 16-bit word. the 10 msbs of this word store the temperature measurement (see table 9 and table 10 ). the temperature conversion formulas using the 10 msbs of the temperature value register are positive temperature = adc code /4 (1) negative temperature = ( adc code ? 512)/4 (2) the msb is removed from adc code in equation 2. internal register structure the ad7417/ad7418 have seven internal registers, as shown in figure 13 . six of these are data registers and one is an address pointer register. the ad7416 has five internal registers (the adc and config2 registers are not applicable to the ad7416). temperature value register (read-only address 0x00) configuration register (read/write address 0x01) t hyst setpoint register (read/write address 0x02) t oti setpoint register (read/write address 0x03) adc value register (read-only address 0x04) config2 register (read/write address 0x05) sda data scl address pointer register (selcts data register for read/write) address serial bus interface 01126-012 figure 13. ad7417/ad7418 register structure address pointer register the address pointer register is an 8-bit register that stores an address that points to one of the six data registers. the first data byte of every serial write operation to the ad7416/ad7417/ ad7418 is the address of one of the data registers, which is stored in the address pointer register, and selects the data register to which subsequent data bytes are written. only the three lsbs of the address pointer register are used to select a data register. table 7. address pointer register p7 1 p6 1 p5 1 p4 1 p3 1 p2 p1 p0 0 0 0 0 0 register select 1 p3 to p7 must be set to 0.
ad7416/ad7417/ad7418 rev. i | page 13 of 24 table 8. register addresses p2 p1 p0 registers 0 0 0 temperature value 0 0 1 configuration register 0 1 0 t hyst setpoint 0 1 1 t oti setpoint 1 0 0 adc value (ad7417/ad7418 only) 1 0 1 config2 (ad7417/ad7418 only) temperature value register (address 0x00) the temperature value register is a 16-bit, read-only register whose 10 msbs store the temperature reading from the adc in 10-bit twos complement format. bit d5 to bit d0 are unused. table 9. temperature value register d15 d14 d13 d12 d11 d10 d9 d8 d7 d6 msb b8 b7 b6 b5 b4 b3 b2 b1 lsb the temperature data format is shown in table 10 . this shows the full theoretical range of the adc from ?128c to +127c, but in practice, the temperature measurement range is limited to the operating temperature range of the device. table 10. temperature data format temperature digital output ?128c 10 0000 0000 ?125c 10 0000 1100 ?100c 10 0111 0000 ?75c 10 1101 0100 ?50c 11 0011 1000 ?25c 11 1001 1100 ?10c 11 1101 1000 ?0.25c 11 1111 1111 0c 00 0000 0000 +0.25c 00 0000 0001 +10c 00 0010 1000 +25c 00 0110 0100 +50c 00 1100 1000 +75c 01 0010 1100 +100c 01 1001 0000 +125c 01 1111 0100 +127c 01 1111 1100 configuration register (address 0x01) the configuration register is an 8-bit, read/write register that is used to set the operating modes of the ad7416/ad7417/ad7418. bit d7 to bit d5 control the channel selection as outlined in table 12 . bits[d7:d5] should always be set to 000 for the ad7416. bit d4 and bit d3 are used to set the length of the fault queue. d2 sets the sense of the oti output. d1 selects the comparator or interrupt mode of operation, and d0 = 1 selects the shutdown mode (default: d0 = 0). table 11. configuration register d7 d6 d5 d4 d3 d2 d1 d0 channel selection fault queue oti polarity cmp/int shutdown the ad7416 contains a temperature-only channel; the ad7417 has four analog input channels and a temperature channel; and the ad7418 has two channels, a temperature channel, and an analog input channel. the temperature channel address for all parts is the same, channel 0. the address for the analog input channel on the ad7418 is channel 4. table 12 outlines the channel selection on the parts, and table 13 shows the fault queue settings. d1 and d2 are explained in the oti output section. table 12. channel selection d7 d6 d5 channel selection 0 0 0 temperature sensor (all parts), channel 0 0 0 1 a in1 (ad7417 only), channel 1 0 1 0 a in2 (ad7417 only), channel 2 0 1 1 a in3 (ad7417 only), channel 3 1 0 0 a in4 (ad7417) and a in (ad7418), channel 4 table 13. fault queue settings d4 d3 number of faults 0 0 1 (power-up default) 0 1 2 1 0 4 1 1 6 t hyst setpoint register (address 0x02) the t hyst setpoint register is a 16-bit, read/write register whose nine msbs store the t hyst setpoint in twos complement format equivalent to the nine msbs of the temperature value register. bit d6 to bit d0 are unused. t oti setpoint register (address 0x03) the t oti setpoint register is a 16-bit, read/write register whose nine msbs store the t oti setpoint in twos complement format equivalent to the nine msbs of the temperature value register. bit 6 to bit 0 are unused. table 14. t hyst setpoint and t oti setpoint registers d15 d14 d13 d12 d11 d10 d9 d8 d7 msb b7 b6 b5 b4 b3 b2 b1 lsb adc value register (address 0x04) the adc value register is a 16-bit, read-only register whose 10 msbs store the value produced by the adc in binary format. bit d5 to bit d0 are unused. table 15 shows the adc value register with 10 msbs containing the adc conversion request. table 15. adc value register d15 d14 d13 d12 d11 d10 d9 d8 d7 d6 msb b8 b7 b6 b5 b4 b3 b2 b1 lsb adc transfer function the designed code transitions occur at successive integer lsb values (that is, 1 lsb, 2 lsb, and so on). the lsb size = vref/1024. the ideal transfer function characteristic for the ad7417 and ad7418 adc is shown in figure 14 .
ad7416/ad7417/ad7418 rev. i | page 14 of 24 analog input adc code 0v 1/2lsb 111...111 111...110 111...000 011...111 000...010 000...001 000...000 +vref ? 1lsb 1lsb ? vref/1024 01126-013 figure 14. ideal transfer function characteristic for the ad7417/ad7418 config2 register (address 0x05) a second configuration register is included in the ad7417/ ad7418 for the functionality of the convst pin. it is an 8-bit register with bit d5 to bit d0 being left at 0. bit d7 determines whether the ad7417/ad7418 should be operated in its default mode (d7 = 0), performing conversions every 355 s or in its convst pin mode (d7 = 1), where conversions start only when the convst pin is used. bit 6 contains the test 1 bit. when this bit is 0, the i 2 c filters are enabled (default). setting this bit to 1 disables the filters. table 16. config2 register d7 d6 d5 d4 d3 d2 d1 d0 conversion mode test 1 0 0 0 0 0 0 serial bus interface control of the ad7416/ad7417/ad7418 is carried out via the i 2 c compatible serial bus. the ad7416/ad7417/ad7418 are connected to this bus as a slave device, under the control of a master device, for example, the processor. serial bus address as with all i 2 c compatible devices, the ad7416/ad7417/ad7418 have a 7-bit serial address. the four msbs of this address for the ad7416 are set to 1001; the ad7417 are set to 0101, and the three lsbs can be set by the user by connecting the a2 to a0 pins to either v dd or gnd. by giving them different addresses, up to eight ad7416/ad7417 devices can be connected to a single serial bus, or the addresses can be set to avoid conflicts with other devices on the bus. the four msbs of this address for the ad7418 are set to 0101, and the three lsbs are all set to 0. if a serial communication occurs during a conversion operation, the conversion stops and restarts after the communication. the serial bus protocol operates as follows: 1. the master initiates data transfer by establishing a start condi- tion, defined as a high-to-low transition on the serial data line, sda, while the serial clock line, scl, remains high. this indicates that an address/data stream follows. all slave peripherals connected to the serial bus respond to the 7-bit address (msb first) plus an r/ w bit, which determines the direction of the data transfer, that is, whether data is written to or read from the slave device. the peripheral whose address corresponds to the transmitted address responds by pulling the data line low during the low period before the ninth clock pulse, known as the acknowl- edge bit. all other devices on the bus now remain idle while the selected device waits for data to be read from or written to it. if the r/ w bit is a 0, then the master writes to the slave device. if the r/ w bit is a 1, then the master reads from the slave device. 2. data is sent over the serial bus in sequences of nine clock pulses, eight bits of data followed by an acknowledge bit from the receiver of data. transitions on the data line must occur during the low period of the clock signal and remain stable during the high period, because a low-to-high transi- tion when the clock is high may be interpreted as a stop signal. 3. when all data bytes have been read or written, stop conditions are established. in write mode, the master pulls the data line high during the 10th clock pulse to assert a stop condition. in read mode, the master device pulls the data line high during the low period before the ninth clock pulse. this is known as no acknowledge. the master then takes the data line low during the low period before the 10th clock pulse, then high during the 10th clock pulse to assert a stop condition. any number of bytes of data can be transferred over the serial bus in one operation, but it is not possible to mix read and write in one operation because the type of operation is determined at the beginning and cannot subsequently be changed without starting a new operation. writing to the ad7416/ad7417/ad7418 depending on the register being written to, there are three different writes for the ad7416/ad7417/ad7418. ? w riting to the address pointer register for a subsequent read. to read data from a particular register, the address pointer register must contain the address of that register. if it does not, the correct address must be written to the address pointer register by performing a single-byte write operation, as shown in figure 15 . the write operation consists of the serial bus address followed by the address pointer byte. no data is written to any of the data registers. ? writing a single byte of data to the configuration register, the config2 register, or to the t oti setpoint or t hyst setpoint registers. the configuration register is an 8-bit register, so only one byte of data can be written to it. if only 8-bit temperature comparisons are required, the temperature lsb can be ignored in t oti and t hyst , and only eight bits need to be written to the t oti setpoint and t hyst setpoint registers. writing a single byte of data to one of these registers consists of the serial bus address, the data register address written to the address pointer register, followed by the data byte
ad7416/ad7417/ad7418 rev. i | page 15 of 24 written to the selected data register. this is illustrated in figure 16 . ? writing two bytes of data to the t oti setpoint or t hyst setpoint register. if 9-bit resolution is required for the temperature setpoints, two bytes of data must be written to the t oti setpoint and t hyst setpoint registers. this consists of the serial bus address, the register address written to the address pointer register, followed by two data bytes written to the selected data register. this is illustrated in figure 17 . scl 1 19 9 s da 1001 start by master ack. by ad741x 1 ack. by ad741x 1 stop by master frame 2 address pointer register byte frame 1 serial bus address byte 1 ad741x = ad7416/ad7417/ad7418. a2 a1 p7 p6 p5 p4 p3 p2 p1 p0 a0 r/w 01126-014 figure 15. writing to the address pointer register to se lect a data register for a subsequent read operation scl 1 1 1 9 9 9 sda 1 0 0 1 start by master ack. by ad741x 1 ack. by ad741x 1 ack. by ad741x 1 stop by master frame 2 address pointer register byte frame 3 data byte frame 1 serial bus address byte scl (continued) sda (continued) a2 a1 p7 p6 p5 p4 p3 p2 p1 p0 d6 d7 d5 d4 d3 d2 d1 d0 a0 r/w 01126-015 1 ad741x = ad7416/ad7417/ad7418. figure 16. writing to the address pointer register followed by a single byte of data to the selected data register scl scl (continued) sda (continued) 11 9 1 19 9 sda 1 0 0 1 start by master ack. by ad741x 1 ack. by ad741x 1 ack. by ad741x 1 stop by master ack. by ad741x 1 stop by master frame 2 address pointer register byte frame 1 serial bus address byte a2 d15 d14 d13 d12 d11 d10 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 a1 p7 p6 p5 p4 p3 p2 p1 p0 a0 r/w 9 frame 3 most significant data byte frame 4 least significant data byte 01126-016 1 ad741x = ad7416/ad7417/ad7418. figure 17. writing to the address pointer regist er followed by two bytes of data to the t oti setpoint or t hyst setpoint register
ad7416/ad7417/ad7418 rev. i | page 16 of 24 reading data from the ad7416/ad7417/ad7418 reading data from the ad7416/ad7417/ad7418 is a single- byte or 2-byte operation. reading back the contents of the configuration register is a single-byte read operation, as shown in figure 18 , with the register address previously having been set by a single-byte write operation to the address pointer register. reading data from the temperature value register, the t oti setpoint or t hyst setpoint register is a 2-byte operation, as shown in figure 19 . it is also possible to read the most significant bit of a 9-bit or 10-bit register in this manner. note that when reading back from the ad7416/ad7417/ ad7418, no more than three bytes of data must be read back. a stop command must be inserted at the end of the read communication. if a stop command is not inserted by the master and the ad7416/ad7417/ad7418 receive more scl cycles than the maximum needed for three bytes of data, then the i 2 c interface on the ad7416/ad7417/ad7418 pulls the sda line low and prevents it from going high again. to recover the ad7416/ad7417/ad7418 interface, the part must be powered off and on again. reference the an-686 application note, implementing an i 2 c? reset at www.analog.com for more information on i 2 c interfaces. scl 1 19 9 s da 1 0 0 1 start by master ack. by ad741x 1 no ack. by master stop by master frame 2 single data byte from ad741x 1 frame 1 serial bus address byte a1 d7 d6 d5 d4 d3 d2 d1 d0 a0 a2 r/w 01126-017 1 ad741x = ad7416/ad7417/ad7418. figure 18. reading a single byte of data from the configuration register scl 1 1 1 9 9 9 s da 1001 start by master ack. by ad741x 1 ack. by master no ack. by master stop by master frame 2 most significant byte from ad741x 1 frame 3 least significant data byte from ad741x 1 frame 1 serial bus address byte scl (continued) sda (continued) a2 a1 d15 d14 d13 d12 d11 d10 d9 d8 d6 d7 d5 d4 d3 d2 d1 d0 a0 r/w 01126-018 1 ad741x = ad7416/ad7417/ad7418. figure 19. reading two bytes of data from the t oti setpoint or t hyst setpoint register
ad7416/ad7417/ad7418 rev. i | page 17 of 24 oti output the oti output has two operating modes that are selected by bit d1 of the configuration register. in the comparator mode, (d1 = 0), the oti output becomes active when the temperature exceeds t oti and remains active until the temperature falls below t hyst . this mode allows the ad7416/ad7417/ad7418 to be used as a thermostat, for example, to control the operation of a cooling fan. t oti t hyst oti output comparator mode oti output interrupt mode 1 in interrupt mode, a read operation or shutdown resets the oti output; otherwise, the oti output remains active indefinitely, once triggered. read 1 read 1 read 1 read 1 read 1 read 1 read 1 01126-019 figure 20. operation of oti output (shown active low) the open-drain configuration of oti allows the oti outputs of several ad7416/ad7417/ad7418 devices to be wire-anded together when in active low mode. the oti output is used to indicate that an out-of-limit tempera- ture excursion has occurred. oti is an open-drain output that can be programmed to be active low by setting bit d2 of the configuration register to 0 or active high by setting bit d2 of the configuration register to 1. in the interrupt mode (d1 = 1), the oti output becomes active when the temperature exceeds t oti and remains active even if the temperature falls below t hyst , until it is reset by a read opera- tion. once oti becomes active by the temperature exceeding t oti , and resets, it remains inactive even if the temperature remains, or subsequently rises again, above t oti . it does not become active again until the temperature falls below t hyst . it then remains active until reset by a read operation. once oti becomes active by the temperature falling below t hyst and then resets, it remains inactive even if the temperature remains, or subsequently falls again, below t hyst . oti is also reset when the ad7416/ad7417/ad7418 are placed in shutdown mode by setting bit d0 of the configuration register to 1. the oti output requires an external pull-up resistor. this can be connected to a voltage different from v dd (for example, to allow interfacing between 5 v and 3.3 v systems) provided that the maximum voltage rating of the oti output is not exceeded. the value of the pull-up resistor depends on the application but should be as large as possible to avoid excessive sink currents at the oti output, which can heat the chip and affect the temperature reading. the maximum value of the pull-up resistor that meets the output high current specification of the oti output is 30 k, but higher values can be used if a lower output current is required. for most applications, a value of 10 k is suitable. fault queue to avoid false triggering of the ad7416/ad7417/ad7418 in noisy environments, a fault queue counter is provided that can be programmed by bit d3 and bit d4 of the configuration register (see table 11 ) to count 1, 2, 4, or 6 fault events before oti becomes active. to trigger oti, the faults must occur consecutively. for example, if the fault queue is set to 4, then four consecutive temperature measurements greater than t oti (or less than t hyst ) must occur. any reading that breaks the sequence resets the fault queue counter, so if there are three readings greater than t oti followed by a reading less than t oti , the fault queue counter is reset without triggering oti. power-on defaults the ad7416/ad7417/ad7418 always power up with the following defaults: ? address pointer pointing to temperature value register comparator mode ? t oti = 80c ? t hyst = 75c ? oti active low ? fault queue = 1 these default settings allow the ad7416/ad7417/ad7418 to be used as a standalone thermostat without any connection to a serial bus. operating modes the ad7416/ad7417/ad7418 have two possible modes of operation depending on the value of d0 in the configuration register. mode 1 normal operation of the ad7416/ad7417/ad7418 occurs when d0 = 0. in this active mode, a conversion takes place every 400 s. after the conversion has taken place, the part partially powers down, consuming typically 350 a of the current until the next conversion occurs. two situations can arise in this mode on the request of a tempera- ture read. if a read occurs during a conversion, the conversion aborts and a new one starts on the stop/repeat start condition. the temperature value that is read is that of the previous com- pleted conversion. the next conversion typically occurs 400 s after the new conversion has begun. if a read is called between conversions, a conversion is initiated on the stop/repeat start condition. after this conversion, the part returns to performing a conversion every 400 s. with v dd = 3 v for each 400 s cycle, the ad7416/ad7417/ ad7418 spend 40 s (or 10% of the time) in conversion mode. the part spends 360 s (or 90% of time) in partial power-down mode. thus, the average power dissipated by the ad7416/ ad7417/ad7418 is 3 mw 0.1 + 1 mw 0.9 = 1.2 mw
ad7416/ad7417/ad7418 rev. i | page 18 of 24 convst pin mode mode 2 conversions are initiated only by using the convst pin. in this method of operation, convst is normally low. for applications where temperature measurements are required at a slower rate, for example, every second, power consumption of the part can be reduced by writing to the part to go to a full power-down between reads. the current consumption in full power-down is typically 0.2 a and full power-down is initiated when d0 = 1 in the configuration register. when a measurement is required, a write operation can be performed to power up the part. the part then performs a conversion and is returned to power-down. the temperature value can be read in full power- down because the i 2 c bus is continuously active. the rising edge of convst starts the power-up time. this power-up time is 4 s. if the convst high time is longer than 4 s, a conversion is initiated on the falling edge of convst and the track-and-hold also enters its hold mode at this time. if the convst high time is less than 4 s, an internal timer, initiated by the rising edge of convst , holds off the track- and-hold and the initiation of conversion until the timer times out (4 s after the rising edge of convst , which corresponds with the power-up time). the convst input remains low at the end of conversion, thus causing the part to enter its power- down mode. in this method of operation, convst is normally low with a high going pulse controlling the power-up, and the conversion starts. the power dissipation in this mode depends on the rate at which reads take place. taking the requirements for a temperature measurement every 100 ms as an example, the optimum power dissipation is achieved by placing the part in full power-down, waking it up every 100 ms, letting it operate for 400 s and putting it into full power-down again. in this case, the average power consumption is calculated as follows. the part spends 40 s (or 0.04% of time) converting with 3 mw dissipation and a 99.96 ms (99.96% of time) in full shutdown with 60 nw dissipation. the convst pin should not be pulsed when reading from or writing to the port. figure 21 shows the recommended minimum times for the convst pulse when the temperature channel is selected. shows the minimum times an analog input channel is selected. figure 22 thus, the average power dissipation is 3 mw 0.004 + 60 nw 0.9996 = 1.2 w convst 100ns 40s 01126-023 the fastest throughput rate at which the ad7416/ad7417/ ad7418 can be operated is 2.5 khz (that is, a read every 400 s conversion period). because t oti and t hyst are 2-byte reads, the read time with the i 2 c operating at 100 kbps would be 270 s. if temperature reads are called too often, reads will overlap with conversions, aborting them continuously, which results in invalid readings. figure 21. convst when temperature channel selected convst start mode convst 100ns 15s 01126-024 the ad7417/ad7418 have an extra mode, set by writing to the msb of the config2 register. figure 22. convst when v in channel selected
ad7416/ad7417/ad7418 rev. i | page 19 of 24 applications information supply decoupling the ad7416/ad7417/ad7418 should be decoupled with a 0.1 f ceramic capacitor between v dd and gnd. this is particularly important if the part is mounted remote from the power supply. power-on reset to ensure proper power-on reset, make sure that the supply voltage on the v dd pin is at 0 v. refer to the an-588 application note, ad7416/ad7417/ad7418 power-on reset circuit at www.analog.com for more information. a failed power-on reset can prevent the default values from being loaded into the ad7416/ ad7417/ad7418 registers. if the correct values are not loaded into the registers, then the device cannot start operating. the output from the temperature value and adc value registers will be a constant value. to restart the device operation, the registers have to be loaded with their default values via the i 2 c bus. therefore, in the event of an inadequate power-on reset and for all three devices, the following registers should be loaded with their default values: ? configuration registerdefault value = 0x00 ? config2 registerdefault value = 0x00 ? t hyst setpoint registerdefault value = 0x4b00 ? t oti setpoint registerdefault value = 0x5500 mounting the ad7416/ad7417/ad7418 the ad7416/ad7417/ad7418 can be used for surface or air temperature sensing applications. if the device is cemented to a surface with thermally conductive adhesive, the die temperature is within about 0.2c of the surface temperature, due to the low power consumption of the device. take care to insulate the back and leads of the device from the air if the ambient air temperature is different from the surface temperature being measured. the gnd pin provides the best thermal path to the die, so the temperature of the die is close to that of the printed circuit ground track. take care to ensure that this is in close thermal contact with the surface being measured. as with any ic, the ad7416/ad7417/ad7418 and its associated wiring and circuits must be kept free from moisture to prevent leakage and corrosion, particularly in cold conditions where condensation is more likely to occur. water resistant varnishes and conformal coatings can be used for protection. the small size of the ad7416 package allows it to be mounted inside sealed metal probes that provide a safe environment for the device. fan controller figure 23 shows a simple fan controller that switches on a cooling fan when the temperature exceeds 80c and switches it off again when the temperature falls below 75c. the ad7416 can be used as a standalone device in this application or with a serial bus interface if different trip temperatures are required. if the ad7416 is used with a bus interface, the sense of oti can be set to active high, q1 and r1 can be omitted, and oti can be con- nected directly to the gate of q2, with r2 as the pull-up resistor. 8 4 3 v dd 3v to 5.5v 12 v ad7416 r1 10k ? r2 10k ? q1 2n3904 or similar q2 logic level mosfet rated to suit fan current 01126-020 figure 23. ad7416 used as a fan controller thermostat figure 24 shows the ad7416 used as a thermostat. the heater switches on when the temperature falls below t hyst and switches off again when the temperature rises above t oti . for this application and for comparator mode, program the oti output active low. 8 4 3 v dd 3v to 5.5v ad7416 r1 10k? relay q1 2n3904 or similar d1 1n4001 heater suply rla1 heater 01126-021 figure 24. ad7416 used as a thermostat
ad7416/ad7417/ad7418 rev. i | page 20 of 24 system with multiple ad7416 devices the three lsbs of the ad7416 serial address can be set by the user, allowing eight different addresses from 1001000 to 1001111. figure 25 shows a system in which eight ad7416 devices are connected to a single serial bus, with their oti outputs wire-anded together to form a common interrupt line. this arrangement means that each device must be read to determine which one has generated the interrupt, and if a unique interrupt is required for each device, the oti outputs can be connected separately to the i/o chip. v dd 3v to 5.5v r1 10k ? ad7416 8 7 6 5 3 2 1 4 ad7416 8 7 6 5 3 2 1 4 ad7416 8 7 6 5 3 2 1 4 ad7416 8 7 6 5 3 2 1 4 ad7416 8 7 6 5 3 2 1 4 ad7416 8 7 6 5 3 2 1 4 ad7416 8 7 6 5 3 2 1 4 ad7416 8 7 6 5 3 2 1 4 super i/o chip processor 0 1126-022 figure 25. multiple connection of ad74 16 devices to a single serial bus
ad7416/ad7417/ad7418 rev. i | page 21 of 24 outline dimensions controlling dimensions are in millimeters; inch dimensions (in parentheses) are rounded-off millimeter equivalents for reference only and are not appropriate for use in design. compliant to jedec standards ms-012-ac 10.00 (0.3937) 9.80 (0.3858) 16 9 8 1 6.20 (0.2441) 5.80 (0.2283) 4.00 (0.1575) 3.80 (0.1496) 1.27 (0.0500) bsc seating plane 0.25 (0.0098) 0.10 (0.0039) 0.51 (0.0201) 0.31 (0.0122) 1.75 (0.0689) 1.35 (0.0531) 0.50 (0.0197) 0.25 (0.0098) 1.27 (0.0500) 0.40 (0.0157) 0.25 (0.0098) 0.17 (0.0067) coplanarity 0.10 8 0 060606-a 45 figure 26. 16-lead standard small outline package [soic_n] narrow body (r-16) dimensions shown in millimeters and (inches) controlling dimensions are in millimeters; inch dimensions (in parentheses) are rounded-off millimeter equivalents for reference only and are not appropriate for use in design. compliant to jedec standards ms-012-a a 012407-a 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 0.50 (0.0196) 0.25 (0.0099) 45 8 0 1.75 (0.0688) 1.35 (0.0532) seating plane 0.25 (0.0098) 0.10 (0.0040) 4 1 85 5.00 (0.1968) 4.80 (0.1890) 4.00 (0.1574) 3.80 (0.1497) 1.27 (0.0500) bsc 6.20 (0.2441) 5.80 (0.2284) 0.51 (0.0201) 0.31 (0.0122) coplanarity 0.10 figure 27. 8-lead standard small outline package [soic_n] narrow body (r-8) dimensions shown in millimeters and (inches)
ad7416/ad7417/ad7418 rev. i | page 22 of 24 16 9 8 1 pin 1 seating plane 8 0 4.50 4.40 4.30 6.40 bsc 5.10 5.00 4.90 0.65 bsc 0.15 0.05 1.20 max 0.20 0.09 0.75 0.60 0.45 0.30 0.19 coplanarity 0.10 compliant to jedec standards mo-153-ab figure 28. 16-lead thin shrink small outline package [tssop] (ru-16) dimensions shown in millimeters compliant to jedec standards mo-187-aa 0.80 0.60 0.40 8 0 4 8 1 5 pin 1 0.65 bsc seating plane 0.38 0.22 1.10 max 3.20 3.00 2.80 coplanarity 0.10 0.23 0.08 3.20 3.00 2.80 5.15 4.90 4.65 0.15 0.00 0 .95 0 .85 0 .75 figure 29. 8-lead mini small outline package [msop] (rm-8) dimensions shown in millimeters
ad7416/ad7417/ad7418 rev. i | page 23 of 24 ordering guide model 1 temperature range temperature error package description branding package option ad7416ar ?40c to +125c 2c 8-lead sta ndard small outline package (soic_n) r-8 ad7416ar-reel ?40c to +125c 2c 8-lead standard small outline package (soic_n) r-8 ad7416ar-reel7 ?40c to +125c 2c 8-lead standard small outline package (soic_n) r-8 ad7416arz ?40c to +125c 2c 8-lead stand ard small outline package (soic_n) r-8 ad7416arz-reel ?40c to +125c 2c 8-lead standard small outline package (soic_n) r-8 ad7416arz-reel7 ?40c to +125c 2c 8-lead standard small outline package (soic_n) r-8 ad7416arm ?40c to +125c 2c 8-lead mini small outline package (msop) c6a rm-8 ad7416arm-reel ?40c to +125c 2c 8-lead mini small outline package (msop) c6a rm-8 ad7416arm-reel7 ?40c to +125c 2c 8-lead mini small outline package (msop) c6a rm-8 ad7416armz ?40c to +125c 2c 8-lead mini small outline package (msop) c6a# rm-8 AD7416ARMZ-REEL ?40c to +125c 2c 8-lead mini small outline package (msop) c6a# rm-8 AD7416ARMZ-REEL7 ?40c to +125c 2c 8-lead mini small outline package (msop) c6a# rm-8 ad7417-wafer bare die wafer ad7417ar ?40c to +125c 2c 16-lead sta ndard small outline package (soic_n) r-16 ad7417ar-reel ?40c to +125c 2c 16-lead standard small outline package (soic_n) r-16 ad7417ar-reel7 ?40c to +125c 2c 16-lead standard small outline package (soic_n) r-16 ad7417arz ?40c to +125c 2c 16-lead stand ard small outline package (soic_n) r-16 ad7417arz-reel ?40c to +125c 2c 16-lead standard small outline package (soic_n) r-16 ad7417arz-reel7 ?40c to +125c 2c 16-lead standard small outline package (soic_n) r-16 ad7417aru ?40c to +125c 2c 16-lead thin shrink small outline package (tssop) ru-16 ad7417aru-reel ?40c to +125c 2c 16-lead th in shrink small outline package (tssop) ru-16 ad7417aru-reel7 ?40c to +125c 2c 16-lead th in shrink small outline package (tssop) ru-16 ad7417aruz ?40c to +125c 2c 16-lead thin shrink small outline package (tssop) ru-16 ad7417aruz-reel ?40c to +125c 2c 16-lead th in shrink small outline package (tssop) ru-16 ad7417aruz-reel7 ?40c to +125c 2c 16-lead th in shrink small outline package (tssop) ru-16 ad7417br ?40c to +85c 1c 16-lead sta ndard small outline package (soic_n) r-16 ad7417br-reel ?40c to +85c 1c 16-lead standard small outline package (soic_n) r-16 ad7417br-reel7 ?40c to +85c 1c 16-lead standard small outline package (soic_n) r-16 ad7417brz ?40c to +85c 1c 16-lead sta ndard small outline package (soic_n) r-16 ad7417brz-reel ?40c to +85c 1c 16-lead standard small outline package (soic_n) r-16 ad7417brz-reel7 ?40c to +85c 1c 16-lead standard small outline package (soic_n) r-16 ad7418achips die ad7418arz ?40c to +125c 2c 8-lead sta ndard small outline package (soic_n) r-8 ad7418arz-reel ?40c to +125c 2c 8-lead standard small outline package (soic_n) r-8 ad7418arz-reel7 ?40c to +125c 2c 8-lead standard small outline package (soic_n) r-8 ad7418arm ?40c to +125c 2c 8-lead mini small outline package (msop) c7a rm-8 ad7418arm-reel ?40c to +125c 2c 8-lead mini small outline package (msop) c7a rm-8 ad7418arm-reel7 ?40c to +125c 2c 8-lead mini small outline package (msop) c7a rm-8 ad7418armz ?40c to +125c 2c 8-lead mi ni small outline package (msop) t0g rm-8 ad7418armz-reel ?40c to +125c 2c 8-lead mini small outline package (msop) t0g rm-8 ad7418armz-reel7 ?40c to +125c 2c 8-lead mini small outline package (msop) t0g rm-8 eval-ad7416/7/8ebz evaluation board 1 z = rohs compliant part.
ad7416/ad7417/ad7418 rev. i | page 24 of 24 notes i 2 c refers to a communications protocol originally developed by philips semiconductors (now nxp semiconductors). ?1998C2010 analog devices, inc. all rights reserved. trademarks and registered trademarks are the property of their respective owners. d01126-0-11/10(i)

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