View ADR318ARJ-R2_4387337.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

precision low drift sot-23 voltage reference with shutdown adr318 rev. a 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 ?2006 analog devices, inc. all rights reserved. features pin configuration 1 shdn 5 gnd 2 v in 3 v out(sense) 4 v out(force) adr318 top view (not to scale) 0 3431-001 initial accuracy: 5 mv maximum, 0.27% maximum low temperature coefficient: 25 ppm/c maximum load regulation: 100 ppm/ma line regulation: 25 ppm/v low supply headroom: 0.6 v figure 1. 5-lead sot-23 wide operating range: (v out + 0.6 v) to 15 v low power: 120 a maximum shutdown to less than 3 a maximum output current: 5 ma wide temperature range: 0c to 70c tiny 5-lead sot-23 package applications battery-powered instrumentation portable medical instruments data acquisition systems industrial process control systems fault protection critical systems general description the adr318 1 is a precision 1.8 v band gap voltage reference featuring high accuracy, high stability, and low power consumption in a tiny footprint. patented temperature drift curvature correction techniques minimize nonlinearity of the voltage change with temperature. the wide operating range and low power consumption with additional shutdown capability make the part ideal for battery-powered applications. the v out (sense) pin enables greater accuracy by supporting full kelvin operation in pcbs employing thin or long traces. the adr318 is a low dropout voltage (ldv) device that provides a stable output voltage from supplies as low as 600 mv above the output voltage. this device is specified over the industrial operating range of 0c to 70c, and is available in a tiny 5-lead sot-23 package. the combination of v out (sense) and shutdown functions also enables a number of unique applications, combining precision reference/regulation with fault decision and overcurrent protection. see the applications section for details. 1 protected by u.s. patent no. 5,969,657; other pa tents pending.
adr318 rev. a | page 2 of 12 table of contents features .............................................................................................. 1 applications....................................................................................... 1 pin configuration............................................................................. 1 general description ......................................................................... 1 revision history ............................................................................... 2 specifications..................................................................................... 3 electrical characteristics............................................................. 3 absolute maximum ratings............................................................ 4 thermal resistance ...................................................................... 4 esd caution.................................................................................. 4 typical performance characteristics ............................................. 5 terminology ...................................................................................... 8 theory of operation .........................................................................9 device power dissipation considerations.................................9 shutdown mode operation .........................................................9 applications..................................................................................... 10 basic voltage reference connection ....................................... 10 precision negative voltage reference without precision resistors....................................................................................... 10 general-purpose current source ............................................ 10 high power performance with current limit ........................... 10 outline dimensions ....................................................................... 12 ordering guide .......................................................................... 12 revision history 10/06rev. 0 to rev. a updated format..................................................................universal changes to ordering guide .......................................................... 12 updated outline dimensions ....................................................... 12 1/03revision 0: initial version
adr318 rev. a | page 3 of 12 specifications electrical characteristics t a = t min to t max , v in = 5 v, unless otherwise noted 1 . table 1. parameter symbol conditions min typ max unit initial accuracy v o 1.795 1.8 1.802 v initial accuracy error v oerr ?0.27 +0.27 % temperature coefficient tc vo 0c to 70c 5 25 ppm/c minimum supply voltage headroom v in C v out 600 mv line regulation v out /v in v in = 2.5 v to 15 v, 10 25 ppm/v 0c < t a < 70c load regulation v out /i load v in = 3 v, i load = 0 ma to 5 ma, 0c < t a < 70c 100 ppm/ma quiescent current i sy no load 100 120 a 0c < t a < 70c 140 a voltage noise e n 0.1 hz to 10 hz 5 v p-p turn-on settling time t r 20 s long-term stability 2 v out 50 ppm/1000 hours output voltage hysteresis v o_hys 40 ppm ripple rejection ratio rrr f in = 60 hz 85 db short circuit to ground i sc v in = 5.0 v 25 ma v in = 15.0 v 30 ma shutdown supply current i shdn 3 a shutdown logic input current i logic 500 na shutdown logic low v inl 0.8 v shutdown logic high v inh 2.4 v 1 t min = 0c, t max = 70c. 2 the long-term stability specification is noncumulative. the drift in subsequent 1000-hour periods is sign ificantly lower than in the first 1000-hour period.
adr318 rev. a | page 4 of 12 absolute maximum ratings at 25 c, unless otherwise noted. table 2. parameter rating 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. supply voltage 18 v output short-circuit duration to gnd observe derating curves storage temperature range: rj-5 package C65c to +125c thermal resistance operating temperature range 0c to 70c ja is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. junction temperature range: rj-5 package C65c to +150c lead temperature range (soldering, 60 sec) 300c table 3. thermal resistance package type ja jc unit 5-lead sot-23 (rj-5) 230 146 c/w esd caution
adr318 rev. a | page 5 of 12 typical performance characteristics 1.802 1.801 1.800 1.799 1.798 0 10203040506070 v out (v) temperature (c) 03431-002 mean + standard deviation mean mean ? standard deviation figure 2. typical output voltage vs. temperature 110 100 90 80 70 2.5 15.0 70c 25c 0c 12.5 10.0 7.5 5.0 supply current (a) input voltage (v) 03431-003 figure 3. supply current vs. input voltage ? 30 ?40 ?50 ?60 ?70 ?80 07 0 60 50 40 30 20 10 load regulation (ppm/ma) temperature (c) 2.5v 10v 03431-004 0 0 ?5 ?10 ?15 ?20 ?25 07 60 50 40 30 20 10 line regulation (ppm/mv) temperature (c) 03431-005 v in = 2.5v to 15v figure 5. line regulation vs. temperature 2.5 70c 25c 0c 2.3 2.1 1.9 1.7 05 4 3 2 1 v in_min (v) load current (ma) 03431-006 figure 6. minimum input voltage vs. load current voltage (2mv/div) time (400ms/div) 03431-007 figure 7. typical output voltage noise 0.1 hz to 10 hz figure 4. load regulation vs. temperature
adr318 rev. a | page 6 of 12 voltage (200mv/div) time (200s/div) load off load on v out v l 03431-011 i l = 5ma i l = 0ma voltage (10mv/div) time (10ms/div) 03431-008 figure 8. typical output voltage noise 10 hz to 10 khz figure 11. load transient response, c l = 0 nf voltage (200mv/div) time (200s/div) load off load on 03431-012 v out v l i l = 5ma i l = 0ma voltage (50mv/div) time (40s/div) 03431-009 v in v out figure 9. line transient response, c bypass = 0 f figure 12. load transient response, c l = 1 nf voltage (200mv/div) time (200s/div) load off load on 03431-013 v out v l i l = 5ma i l = 0ma voltage (50mv/div) time (40s/div) 03431-010 v in v out figure 10. line transient response, c bypass = 0.1 f figure 13. load transient response, c l = 100 nf
adr318 rev. a | page 7 of 12 voltage (50mv/div) time (40s/div) v in v out 03431-014 voltage (1v/div) time (4s/div) v out shutdown pin 03431-016 figure 14. turn-on/turn-off response at 5 v, r load = 1.8 k figure 16. shutdown pin response voltage (2v/div) time (100s/div) v in v out 03431-015 figure 15. turn-on/turn-off response at 5 v, r load = 1.8 k, c bypass = 0.1 f
adr318 rev. a | page 8 of 12 terminology temperature coefficient temperature coefficient is the change of output voltage with respect to operating temperature changes, normalized by the output voltage at 25c. this parameter is expressed in ppm/c, and can be determined with the following equation: () () () () 6 10 c 25 c ppm ? ? = ? ? ? ? ? ? 1 2 o 1 o 2 o o t t v t v t v tcv (1) where: v o (25c) = v o at 25c. v o (t 1 ) = v o at temperature 1. v o (t 2 ) = v o at temperature 2. long-term stability long-term stability is the typical shift of output voltage at 25c on a sample of parts subjected to a test of 1000 hours at 25c. v o = v o (t 0 ) ? v o (t 1 ) [] () () () 6 10 ppm ? = 0 o 1 o 0 o o t v t v t v v (2) where: v o (t 0 ) = v o at 25c at time 0. v o (t 1 ) = v o at 25c after 1000 hours of operation at 25c. thermal hysteresis thermal hysteresis is the change of output voltage after the device is cycled through temperature from +25c to ?40c to +125c and back to +25c. this is a typical value from a sample of parts put through such a cycle. v o_hys = v o (25c) ? v o_tc [] ( ) () 6 _ _ 10 c 25 c 25 ppm ? = o tc o o hys o v v v v (3) where: v o (25c) = v o at 25c. v o_tc = v o at 25c after temperature cycle at +25c to ?40c to +125c and back to +25c.
adr318 rev. a | page 9 of 12 theory of operation device power dissipation considerations band gap references are the high performance solution for low supply voltage and low power voltage reference applications, and the adr318 is no exception. the uniqueness of this lies in its architecture. by observing the adr318 is capable of delivering load currents up to 5 ma with an input voltage that ranges from 2.4 v to 15 v. when this device is used in applications with high input voltages, care should be taken to avoid exceeding the specified maximum power dissipation or junction temperature. doing so results in premature device failure. the following formula should be used to calculate the devices maximum junction temperature or dissipation: figure 17 , the ideal zero temperature coefficient (tc) band gap voltage is referenced to the output, not to ground. therefore, if noise exists on the ground line, it is greatly attenuated on v out . the band gap cell consists of the pnp pair, q51 and q52, running at unequal current densities. the difference in voltage base emitter (v be ) results in a voltage with a positive tc that is amplified by the ratio of 2 (r58/r54). this proportional-to-absolute temperature (ptat) voltage, combined with v be q51 and v be q52, produces the stable band gap voltage. ja a j d t t p ? = (4) where: reduction in band gap curvature is performed by the ratio of the resistors r44 and r59, one of which is linearly temperature dependent. precision laser-trimming and other patented circuit techniques are used to further enhance the drift performance. t j = the junction temperature. t a = the ambient temperatures. p d = the device power dissipation. shdn gnd q51 r54 r59 q1 r44 r49 r58 r60 r61 r48 r53 q52 v out(force) v out(sense) v in 03431-017 ja = the device package thermal resistance. shutdown mode operation the adr318 includes a shutdown feature that is ttl/cmos compatible. a logic low or a 0 v condition on the shdn pin is required to turn the device off. during shutdown, the output of the reference becomes a high impedance state where its potential would then be determined by external circuitry. if the shutdown feature is not used, the shdn pin should be connected to v in (pin 2). figure 17. simpli fied schematic
adr318 rev. a | page 10 of 12 applications basic voltage reference connection general-purpose current source the circuit in figure 18 illustrates the basic configuration for the adr318. decoupling capacitors are not required for circuit stability. the adr318 is capable of driving capacitative loads from 0 f to 10 f. however, a 0.1 f ceramic output capacitor is recommended to absorb and deliver the charge as is required by a dynamic load. many times in low power applications, the need arises for a precision current source that can operate on low supply voltages. as shown in figure 2 0 , the adr318 can be configured as a precision current source. the illustrated circuit configuration is a floating current source with a grounded load. the reference output voltage is bootstrapped across r1 that sets the output current into the load. with this configuration, circuit precision is maintained for load currents in the range of the reference supply current, typically 90 ma, to approximately 5 ma. the supply current is a function of i set and increases slightly at a given i set . shutdown input shdn adr318 gnd v out(f) v out(s) v in output c i 0.1f c o 0.1f 03431-018 + v dd u1 adr318 shdn v out(f) v out(s) gnd r1 r l i sy (i set ) i sy adj 0.1f i out = i set + i sv (i set ) i set v in 03431-020 figure 18. voltage reference connection precision negative voltage reference without precision resistors a negative reference can be easily generated by combining the adr318 with an op amp. figure 19 shows this simple negative reference configuration. v out(f) and v out(s) are at virtual ground and therefore the negative reference can be taken directly from the output of the op amp. the op amp should be a dual-supply, low offset, rail-to-rail amplifier, such as the op1177. figure 20. general-purpose current source high power performance with current limit + v dd ?vref op1177 adr318 shdn v out(s) v out(f) gnd v in ?v ss 03431-019 in some cases, the user may want higher output current delivered to a load and still achieve better than 0.5% accuracy out of the adr318. the accuracy for a reference is normally specified with no load (see the specifications section). however, the output voltage changes with the load current. the circuit in figure 21 provides high current without compromising the accuracy of the adr318. the power bipolar junction transistor (bjt) q1 provides the required current, up to 1 a. the adr318 delivers the base drive to q1 through the force pin. the sense pin of the adr318 is a regulated output and is connected to the load. figure 19. negative reference
adr318 rev. a | page 11 of 12 the transistor q2 protects q1 during short-circuit limit faults by robbing its base drive. the maximum current is i l, max = 0.6 v/r s . a similar circuit function can also be achieved using the darlington transistor configuration, as shown in figure 22 . adr318 shdn gnd v out(f) v out(s) v in v in r s r1 4.7k ? q1 q2 r l 03431-022 adr318 shdn gnd v out(f) v out(s) v in v in r s r1 4.7k ? r l q1 q2 03431-021 figure 22. high output current with darlington drive configuration figure 21. high power performance with current limit
adr318 rev. a | page 12 of 12 outline dimensions pin 1 1.60 bsc 2.80 bsc 1.90 bsc 0.95 bsc 5 12 3 4 0.22 0.08 10 5 0 0.50 0.30 0.15 max seating plane 1.45 max 1.30 1.15 0.90 2.90 bsc 0.60 0.45 0.30 compliant to jedec standards mo-178-aa figure 23. 5-lead small outline transistor package [sot-23] (rj-5) dimensions shown in millimeters ordering guide model temperature range package description package option branding output voltage ordering quantity ADR318ARJ-R2 0c to 70c 5-lead sot-23 rj-5 rea 1.800 v 250 adr318arj-reel 0c to 70c 5-lead sot-23 rj-5 rea 1.800 v 10,000 adr318arj-reel7 0c to 70c 5-lead sot-23 rj-5 rea 1.800 v 3,000 adr318arjz-reel7 1 0c to 70c 5-lead sot-23 rj-5 l28 1.800 v 3,000 1 z = pb-free part. ?2006 analog devices, inc. all rights reserved. trademarks and registered trademarks are the prop erty of their respective owners. c03431-0-10/06(a)

▲Up To Search▲

Price & Availability of ADR318ARJ-R2

	To Download ADR318ARJ-R2 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .