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august 2006 rev 11 1/41 1 m41t62, m41t63 m41t64, M41T65 serial access real-time clock with alarms feature summary counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century 32 khz crystal oscilla tor integrating load capacitance and high crystal series resistance operation oscillator stop detect ion monitors clock operation serial interface supports i 2 c bus (400khz) 350na timekeeping current @ 3v low operating current of 35 a (@400khz) timekeeping down to 1.0v 1.3v to 4.4v i 2 c bus operating voltage 32khz square wave on power-up to drive a microcontroller in low power mode (m41t62/63/64) programmable (1hz to 32khz) square wave (m41t63/64) programmable alarm with interrupt function (m41t62/65) accurate programmable watchdog (from 62.5ms to 31 min) software clock calibration to compensate deviation of crystal due to temperature automatic leap year compensation operating temperature of ?40 to 85c lead-free 16-pin qfn package lithium ion rechargeable operation table 1 qfn16 (q) 3mm x 3mm 1 xi 2 xo 3 4 ai11107 st qfn16 smt crystal vsoj20 (47.6mm 2 ) guard ring (21.5mm 2 ) gnd plane 32khz crystal + qfn 16 vs. vsoj20 table 1. device options basic rtc alarms osc fail detect watchdog timer calibration sqw output irq output wdo output f 32k output m41t62 ?? ? ? ??? m41t63 ?? ? ? ?? ? m41t64 ?? ? ? ?? ? M41T65 ?? ? ? ? ?? www.st.com
contents m41t62/63/64/65 2/40 contents 1 summary description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.1 2-wire bus characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.1.1 bus not busy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.1.2 start data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.1.3 stop data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.1.4 data valid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.1.5 acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.2 read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.3 write mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3 clock operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1 timekeeper? registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.2 calibrating the clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.3 setting alarm clock registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.4 watchdog timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.5 watchdog output (wdo - m41t63/65 only) . . . . . . . . . . . . . . . . . . . . . . . 26 3.6 square wave output (m41t62/63/64) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.7 full-time 32khz square wave output (m41t64) . . . . . . . . . . . . . . . . . . . . 27 3.8 century bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.9 output driver pin (m41t62/65) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.10 oscillator stop detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.11 initial power-on defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 4 maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 5 dc and ac parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6 package mechanical information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7 part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 8 revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
m41t62/63/64/65 list of tables 3/40 list of tables table 1. device options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 table 2. signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 table 3. m41t62 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 table 4. m41t63 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 table 5. m41t64 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 table 6. M41T65 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 table 7. alarm repeat modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 table 8. square wave output frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 table 9. initial power-on default values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 table 10. century bits examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 table 11. absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 table 12. operating and ac measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 table 13. capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 table 14. dc characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 table 15. crystal electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 table 16. oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 table 17. ac characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 table 18. qfn16 ? 16-lead, quad, flat package, no lead, 3x3mm body size, mechanical data . . . 36 table 19. ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 table 20. revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
list of figures m41t62/63/64/65 4/40 list of figures figure 1. m41t62 logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 figure 2. m41t64 logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 figure 3. m41t63 logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 figure 4. M41T65 logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 figure 5. m41t62 connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 figure 6. m41t63 connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 figure 7. m41t64 connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 figure 8. M41T65 connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 figure 9. m41t62 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 figure 10. m41t63 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 figure 11. m41t64 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 figure 12. M41T65 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 figure 13. hardware hookup for supercap? back-up operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 figure 14. serial bus data transfer sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 figure 15. acknowledgement sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 figure 16. slave address location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 17. read mode sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 18. alternative read mode sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5 figure 19. write mode sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 figure 20. crystal accuracy across temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 figure 21. calibration waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 figure 22. alarm interrupt reset waveform. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 figure 23. ac measurement i/o waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 figure 24. crystal isolation example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 figure 25. bus timing requirements sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 figure 26. qfn16 ? 16-lead, quad, flat package, no lea d, 3x3mm body size, outline . . . . . . . . . . . 35 figure 27. qfn16 ? 16-lead, quad, flat package, no lead, 3x3mm, recommended footprint. . . . . . 36 figure 28. 32khz crystal + qfn16 vs. vsoj20 mechanical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
m41t62/63/64/65 summary description 5/40 1 summary description the m41t6x serial access timekeeper ? is a low power serial rtc with a built-in 32.768 khz oscillator (external crystal co ntrolled). eight registers (see table 3 on page 19 ) are used for the clock/calendar function and are configured in binary coded decimal (bcd) format. an additional 8 registers provide status/control of alarm, 32khz output, calibration, and watchdog functions. addresses and data are transferred serially via a two line, bi-directional i 2 c interface. the built-in address register is incremented automatically after each write or read data byte. functions available to the user include a time-of-day clock/calendar, alarm interrupts (m41t62/65), 32khz output (m41t64), programmable square wave output (m41t62/63/64), and watchdog output (m41t63/65). the eight clock address locations contain the century, year, month, date, day, hour, minute, second and tenths/hundredths of a second in 24 hour bcd format. corrections for 28-, 29- (leap year), 30- and 31-day months are made automatically. the m41t6x is supplied in a 16-pin qfn. figure 1. m41t62 logic diagram 1. open drain. 2. defaults to 32khz on power-up. scl v cc m41t62 v ss sda irq/out (1) sqw (2) xi xo ai09103
summary description m41t62/63/64/65 6/40 figure 2. m41t64 logic diagram 1. open drain. 2. defaults to 32khz on power-up. figure 3. m41t63 logic diagram 1. open drain. 2. defaults to 32khz on power-up. scl v cc m41t64 v ss sda f 32k (2) sqw (1) xi xo ai09108 scl v cc m41t63 v ss sda wdo (1) sqw (2) xi xo ai09189
m41t62/63/64/65 summary description 7/40 figure 4. M41T65 logic diagram 1. open drain. figure 5. m41t62 connections 1. sqw output defaults to 32khz upon power-up. 2. open drain. scl v cc M41T65 v ss sda wdo (1) irq/ft/out (1) xi xo ai09109 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 nc nc nc nc nc nc xi xo sqw (1) v ss v ss v cc nc scl sda irq/out (2) ai09100
summary description m41t62/63/64/65 8/40 figure 6. m41t63 connections 1. sqw output defaults to 32khz upon power-up. 2. open drain. figure 7. m41t64 connections 1. enabled on power-up. 2. open drain. figure 8. M41T65 connections 1. open drain. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 nc nc nc nc nc nc xi xo sqw (1) v ss v ss v cc nc scl sda wdo (2) ai09190 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 nc nc nc nc nc nc xi xo f 32k (1) v ss v ss v cc nc scl sda sqw (2) ai09101 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 nc nc nc nc nc nc xi xo wdo (1) v ss v ss v cc nc scl sda irq/ft/out (1) ai09102
m41t62/63/64/65 summary description 9/40 figure 9. m41t62 block diagram 1. open drain. 2. defaults to 32khz on power-up. figure 10. m41t63 block diagram 1. open drain. 2. defaults to 32khz on power-up. table 2. signal names xi oscillator input xo oscillator output sda serial data input/output scl serial clock input irq /out interrupt or out output (open drain) irq /ft/out interrupt, frequency test, or out output (open drain) sqw programmable square wave - defaults to 32khz on power-up (open drain for m41t64 only) f 32k dedicated 32khz output (m41t64 only) wdo watchdog timer output (open drain) v cc supply voltage v ss ground real time clock calendar rtc w/alarm oscillator fail detect square wave watchdog irq/out (1) sqw (2) ofie sda scl afe sqwe i 2 c interface 32khz oscillator xtal ai08899a real time clock calendar rtc w/alarm oscillator fail detect square wave watchdog sqw (2) wdo (1) sda scl sqwe i 2 c interface 32khz oscillator xtal ai09191
summary description m41t62/63/64/65 10/40 figure 11. m41t64 block diagram 1. defaults enabled on power-up. 2. open drain. figure 12. M41T65 block diagram 1. open drain. real time clock calendar rtc w/alarm oscillator fail detect square wave watchdog sqw (2) f 32k (1) 32ke sda scl sqwe i 2 c interface 32khz oscillator xtal ai09192 real time clock calendar rtc w/alarm oscillator fail detect watchdog irq/ft/out (1) wdo (1) ofie sda scl ft afe i 2 c interface 32khz oscillator xtal ai09193
m41t62/63/64/65 summary description 11/40 figure 13. hardware hookup for supercap? back-up operation 1. diode required on open drain pin (m 41t65 only) for supercap (or battery) back-up. low threshold bat42 diode recommended. 2. for m41t62 and M41T65 (open drain). 3. for m41t63 and M41T65 (open drain). 4. for m41t64 (open drain). ai10400b v cc port reset input sqwin serial clock line serial data line 32khz clkin xo xi m41t6x mcu v ss irq/ft/out (2) wdo (3) sqw (4) f 32k sda scl v cc v cc (1)
operation m41t62/63/64/65 12/40 2 operation the m41t6x clock operates as a slave device on the serial bus. access is obtained by implementing a start condition followed by the correct slave address (d0h). the 16 bytes contained in the device can then be accessed sequentially in the following order: 1 st byte: tenths/hundredths of a second register 2 nd byte: seconds register 3 rd byte: minutes register 4 th byte: hours register 5 th byte: square wave/day register 6 th byte: date register 7 th byte: century/month register 8 th byte: year register 9 th byte: calibration register 10 th byte: watchdog register 11 th - 15 th bytes: alarm registers 16th byte: flags register 2.1 2-wire bus characteristics the bus is intended for communication between di fferent ics. it consists of two lines: a bi- directional data signal (sda) and a clock signal (scl). both the sda and scl lines must be connected to a positive supply voltage via a pull-up resistor. the following protocol has been defined: data transfer may be initiated only when the bus is not busy. during data transfer, the data line must remain stable whenever the clock line is high. changes in the data line, while the clock line is high, will be inte rpreted as control signals. accordingly, the following bus conditions have been defined: 2.1.1 bus not busy both data and clock lines remain high. 2.1.2 start data transfer a change in the state of the data line, from high to low, while the clock is high, defines the start condition. 2.1.3 stop data transfer a change in the state of the data line, from low to high, while the clock is high, defines the stop condition.
m41t62/63/64/65 operation 13/40 2.1.4 data valid the state of the data line represents valid data when after a start condition, the data line is stable for the duration of the high period of the clock signal. the data on the line may be changed during the low period of the clock signal. there is one clock pulse per bit of data. each data transfer is initiated with a start co ndition and terminated with a stop condition. the number of data bytes transferred between the start and stop conditions is not limited. the information is transmitted byte-wide and each receiver acknowledges with a ninth bit. by definition a device that gives out a message is called ?transmitter,? the receiving device that gets the message is called ?receiver.? th e device that controls the message is called ?master.? the devices that are controlled by the master are called ?slaves.? 2.1.5 acknowledge each byte of eight bits is followed by one acknowledge bit. this acknowledge bit is a low level put on the bus by the receiver whereas the master generates an extra acknowledge related clock pulse. a slave receiver which is addressed is obliged to generate an acknowledge after the reception of each byte that has been clocked out of the slave transmitter. the device that acknowledges has to pull down the sda line during the acknowledge clock pulse in such a way that the sda line is a stable low during the high period of the acknowledge related clock pulse. of course, setup and hold times must be taken into account. a master receiver must signal an end of data to the slave transmitter by not generating an acknowledge on the last byte that has been clocked out of the slave. in this case the transmitter must leave the data line high to enable the master to generate the stop condition. figure 14. serial bus data transfer sequence ai00587 data clock data line stable data valid start condition change of data allowed stop condition
operation m41t62/63/64/65 14/40 figure 15. acknowledgement sequence 2.2 read mode in this mode the master reads the m41t6x slave after setting the slave address (see figure 17 on page 15 ). following the write mode control bit (r/w =0) and the acknowledge bit, the word address 'an' is written to the on-chip address pointer. next the start condition and slave address are repeated followed by the read mode control bit (r/w =1). at this point the master transmitter becomes the master receiver. the data byte which was addressed will be transmitted and th e master receiver will send an acknowledge bit to the slave transmitter. the address pointer is only incremented on reception of an acknowledge clock. the m41t6x slave transmit ter will now place the da ta byte at address an+1 on the bus, the master receiver reads and acknowledges the new byte and the address pointer is incremented to ?an+2.? this cycle of reading consecutive addresses will continue until the mast er receiver sends a stop condition to the slave transmitter. the system-to-user transfer of clock data will be halted whenever the address being read is a clock address (00h to 07h). the update will resume due to a stop condition or when the pointer increments to any non-clock address (08h-0fh). note: this is true both in read mode and write mode. an alternate read mode may also be implemented whereby the master reads the m41t6x slave without first writing to the (volatile) address pointer. the first address that is read is the last one stored in the pointer (see figure 18 on page 15 ). ai00601 data output by receiver data output by transmitter scl from master start clock pulse for acknowledgement 12 89 msb lsb
m41t62/63/64/65 operation 15/40 figure 16. slave address location figure 17. read mode sequence figure 18. alternative read mode sequence ai00602 r/w slave address start a 01000 11 msb lsb ai00899 bus activity: ack s ack ack ack no ack stop start p sda line bus activity: master r/w data n data n+1 data n+x word address (an) slave address s start r/w slave address ack ai00895 bus activity: ack s ack ack ack no ack stop start p sda line bus activity: master r/w data n data n+1 data n+x slave address
operation m41t62/63/64/65 16/40 2.3 write mode in this mode the master transmitter transmits to th e m41t6x slave receiver. bus protocol is shown in figure 19 on page 16 . following the start condition and slave address, a logic '0' (r/w =0) is placed on the bus and indicates to the addresse d device that word address ?an? w ill follow and is to be written to the on-chip address pointer. the data word to be written to the memory is strobed in next and the internal address pointer is incremented to the next address location on the reception of an acknowledge clock. the m41t6x slave receiver will send an acknowledge cl ock to the master transmit ter after it has received the slave address see figure 16 on page 15 and again after it has received the word address and each data byte. figure 19. write mode sequence ai00591 bus activity: ack s ack ack ack ack stop start p sda line bus activity: master r/w data n data n+1 data n+x word address (an) slave address
m41t62/63/64/65 clock operation 17/40 3 clock operation the m41t6x is driven by a quartz-controlled oscillator with a nominal frequency of 32.768khz. the accuracy of the real-time clock depends on the frequency of the quartz crystal that is used as the time-base for the rtc. the eight byte clock register (see table 3: m41t62 register map , table 4: m41t63 register map , table 5: m41t64 register map , and table 6: M41T65 register map ) is used to both set the clock and to read the date and time from the clock, in a binary coded decimal format. tenths/hundredths of seconds, seconds, minutes, and hours are contained within the first four registers. a write to any clock register will result in th e tenths/hundredths of seconds being reset to ?00,? and tenths/hundredths of seconds cannot be written to any value other than ?00.? bits d0 through d2 of register 04h contain the day (day of week). registers 05h, 06h, and 07h contain the date (day of month), month, and years. the ninth clock register is the calibration register (this is described in the clock calibration section). bit d7 of register 01h contains the stop bit (st). setting this bi t to a '1' will cause the oscillator to stop. when reset to a '0' the oscillator rest arts within one second (typical). upon initial power-up, the user should set the st bit to a '1,' then immediately reset the st bit to '0.' this provides an additiona l ?kick-start? to the oscillator circuit. bit d7 of register 02h (minut e register) contains the oscilla tor fail interrupt enable bit (ofie). when the user se ts this bit to '1,' any condition wh ich sets the oscillator fail bit (of) (see oscillator stop detection on page 28 ) will also generate an interrupt output. bits d6 and d7 of clock register 06h (century/month register) contain the century bit 0 (cb0) and century bit 1 (cb1). a write to any location within the first eight bytes of the clock register (00h-07h), including the ofie bit, rs0-rs 3 bit, and cb0-cb1 bits will re sult in an update of the system clock and a reset of the divider chain. this could result in an inadvertent change of the current time. these non-clock related bits should be written prior to setting the clock, and remain unchanged until such time as a new clock time is also written. the eight clock registers may be read one byte at a time, or in a sequential block. provision has been made to assure that a clock update does not occur while any of the eight clock addresses are being read. if a clock address is being read, an update of the clock registers will be halted. this will prevent a trans ition of data during the read.
clock operation m41t62/63/64/65 18/40 3.1 timekeeper ? registers the m41t6x offers 16 internal registers which contain clock, calibration, alarm, watchdog, flags, and square wave. the clock registers are memory locations which contain external (user accessible) and internal copies of the data (usually referred to as biport ? timekeeper cells). the external copies are ind ependent of inte rnal functions except that they are updated periodically by the simultaneous transfer of the incremented internal copy. the internal divider (or clock) chain will be re set upon the completion of a write to any clock address (00h to 07h). the system-to-user transfer of clock data will be halted whenever the address being read is a clock address (00h to 07h). the update will resu me either due to a st op condition or when the pointer increments to a non-clock address. timekeeper and alarm registers store data in bcd format. calibration, watchdog, and square wave bits are written in a binary format.
m41t62/63/64/65 clock operation 19/40 table 3. m41t62 register map (1) 1. keys: 0 = must be set to '0' af = alarm flag (read only) afe = alarm flag enable flag bmb0 - bmb4 = watchdog multiplier bits cb0-cb1 = century bits of = oscillator fail bit ofie = oscillator fa il interrupt enable bit out = output level rb0 - rb2 = watchdog resolution bits rpt1-rpt5 = alarm repeat mode bits rs0-rs3 = sqw frequency bits s = sign bit sqwe = square wave enable bit st = stop bit wdf = watchdog flag bit (read only) addr function/range bcd format d7 d6 d5 d4 d3 d2 d1 d0 00h 0.1 seconds 0.01 seconds 10ths/100ths of seconds 00-99 01h st 10 seconds seconds seconds 00-59 02h ofie 10 minutes minutes minutes 00-59 03h 0 0 10 hours hours (24 hour format) hours 00-23 04h rs3 rs2 rs1 rs0 0 day of week day 01-7 05h 0 0 10 date date: day of month date 01-31 06h cb1 cb0 0 10m month century/ month 0-3/01-12 07h 10 years year year 00-99 08h out 0 s calibration calibration 09h rb2 bmb4 bmb3 bmb2 bmb1 bmb0 rb1 rb0 watchdog 0ah afe sqwe 0 al 10m alarm month al month 01-12 0bh rpt4 rpt5 ai 10 date alarm date al date 01-31 0ch rpt3 0 ai 10 hour alarm hour al hour 00-23 0dh rpt2 alarm 10 minutes alarm minutes al min 00-59 0eh rpt1 alarm 10 seconds alarm seconds al sec 00-59 0fh wdf af 0 0 0 of 0 0 flags
clock operation m41t62/63/64/65 20/40 table 4. m41t63 register map (1) 1. keys: 0 = must be set to '0' af = alarm flag (read only) bmb0 - bmb4 = watchdog multiplier bits cb0-cb1 = century bits of = oscillator fail bit rb0 - rb2 = watchdog resolution bits rpt1-rpt5 = alarm repeat mode bits rs0-rs3 = sqw frequency bits s = sign bit sqwe = square wave enable bit st = stop bit wdf = watchdog flag bit (read only) addr function/range bcd format d7 d6 d5 d4 d3 d2 d1 d0 00h 0.1 seconds 0.01 seconds 10ths/100ths of seconds 00-99 01h st 10 seconds seconds seconds 00-59 02h 0 10 minutes minutes minutes 00-59 03h 0 0 10 hours hours (24 hour format) hours 00-23 04h rs3 rs2 rs1 rs0 0 day of week day 01-7 05h 0 0 10 date date: day of month date 01-31 06h cb1 cb0 0 10m month century/ month 0-3/01-12 07h 10 years year year 00-99 08h 0 0 s calibration calibration 09h rb2 bmb4 bmb3 bmb2 bmb1 bmb0 rb1 rb0 watchdog 0ah 0 sqwe 0 al 10m alarm month al month 01-12 0bh rpt4 rpt5 ai 10 date alarm date al date 01-31 0ch rpt3 0 ai 10 hour alarm hour al hour 00-23 0dh rpt2 alarm 10 minutes alarm minutes al min 00-59 0eh rpt1 alarm 10 seconds alarm seconds al sec 00-59 0fh wdf af 0 0 0 of 0 0 flags
m41t62/63/64/65 clock operation 21/40 table 5. m41t64 register map (1) 1. keys: 0 = must be set to '0' 32ke = 32khz enable bit af = alarm flag (read only) bmb0 - bmb4 = watchdog multiplier bits cb0-cb1 = century bits of = oscillator fail bit rb0 - rb2 = watchdog resolution bits rpt1-rpt5 = alarm repeat mode bits rs0-rs3 = sqw frequency bits s = sign bit sqwe = square wave enable bit st = stop bit wdf = watchdog flag bit (read only) addr function/range bcd format d7 d6 d5 d4 d3 d2 d1 d0 00h 0.1 seconds 0.01 seconds 10ths/100ths of seconds 00-99 01h st 10 seconds seconds seconds 00-59 02h 0 10 minutes minutes minutes 00-59 03h 0 0 10 hours hours (24 hour format) hours 00-23 04h rs3 rs2 rs1 rs0 0 day of week day 01-7 05h 0 0 10 date date: day of month date 01-31 06h cb1 cb0 0 10m month century/ month 0-3/01-12 07h 10 years year year 00-99 08h 0 0 s calibration calibration 09h rb2 bmb4 bmb3 bmb2 bmb1 bmb0 rb1 rb0 watchdog 0ah 0 sqwe 32ke al 10m alarm month al month 01-12 0bh rpt4 rpt5 ai 10 date alarm date al date 01-31 0ch rpt3 0 ai 10 hour alarm hour al hour 00-23 0dh rpt2 alarm 10 minutes alarm minutes al min 00-59 0eh rpt1 alarm 10 seconds alarm seconds al sec 00-59 0fh wdf af 0 0 0 of 0 0 flags
clock operation m41t62/63/64/65 22/40 m table 6. M41T65 register map (1) 1. keys: 0 = must be set to '0' af = alarm flag (read only) afe = alarm flag enable flag bmb0 - bmb4 = watchdog multiplier bits cb0-cb1 = century bits ft = frequency test bit of = oscillator fail bit ofie = oscillator fa il interrupt enable bit out = output level rb0 - rb2 = watchdog resolution bits rpt1-rpt5 = alarm repeat mode bits s = sign bit st = stop bit wdf = watchdog flag bit (read only) addr function/range bcd format d7 d6 d5 d4 d3 d2 d1 d0 00h 0.1 seconds 0.01 seconds 10ths/100ths of seconds 00-99 01h st 10 seconds seconds seconds 00-59 02h ofie 10 minutes minutes minutes 00-59 03h 0 0 10 hours hours (24 hour format) hours 00-23 04h 0 0 0 0 0 day of week day 01-7 05h 0 0 10 date date: day of month date 01-31 06h cb1 cb0 0 10m month century/ month 0-3/01-12 07h 10 years year year 00-99 08h out ft s calibration calibration 09h rb2 bmb4 bmb3 bmb2 bmb1 bmb0 rb1 rb0 watchdog 0ah afe 0 0 al 10m alarm month al month 01-12 0bh rpt4 rpt5 ai 10 date alarm date al date 01-31 0ch rpt3 0 ai 10 hour alarm hour al hour 00-23 0dh rpt2 alarm 10 minutes alarm minutes al min 00-59 0eh rpt1 alarm 10 seconds alarm seconds al sec 00-59 0fh wdf af 0 0 0 of 0 0 flags
m41t62/63/64/65 clock operation 23/40 3.2 calibrating the clock the m41t6x is driven by a quartz contro lled oscillator with a no minal frequency of 32,768hz. the accuracy of the real-time clock depends on the frequency of the quartz crystal that is used as the time-base for the rtc. the accuracy of the clock is dependent upon the accuracy of the crystal, and the match betwe en the capacitive load of the oscillator circuit and the capacitive load for which the cr ystal was trimmed. the m41t6x oscillator is designed for use with a 6pf crystal load capa citance. when the calibration circuit is properly employed, accuracy improves to better than 2 ppm at 25c. the oscillation rate of crystals changes with temperature (see figure 20 on page 24 ). therefore, the m41t6x design employs periodic counter correction. the calibration circuit adds or subtracts counts from the oscillator divider circui t at the divide by 256 stage, as shown in figure 21 on page 24 . the number of times pulses which are blanked (subtracted, negative calibration) or split (added, positive calibration) depends upon the value loaded into the five calibration bits found in the calibration register. adding counts speeds the clock up, subtracting counts slows the clock down. the calibration bits occupy the five lower order bits (d4-d0) in the calibration register (08h). these bits can be set to represent any value between 0 and 31 in binary form. bit d5 is a sign bit; '1' indicates positive calibration, '0' indicates negative calibration. calibration occurs within a 64 minute cycle. the first 62 minutes in the cycle may, once per minute, have one second either shortened by 128 or lengthened by 256 oscillator cycles. if a binary '1' is loaded into the register, only th e first 2 minutes in the 64 minute cycle will be modified; if a binary 6 is loaded, the first 12 will be affected, and so on. therefore, each calibration step has the effect of adding 512 or subtracting 256 oscillator cycles for every 125,829,120 ac tual oscillator cycles, that is +4.068 or ?2.034 ppm of adjustment per calibration step in the calibration register. assuming that the oscillator is running at exactly 32,768 hz, ea ch of the 31 increments in the calibration byte would represent +10.7 or ?5.35 seconds per day which corresponds to a total range of +5.5 or ?2.75 minutes per month (see figure 21 on page 24 ). two methods are available for ascertaining how much calibration a given m41t6x may require: the first involves setting the clock, letting it run for a month and comparing it to a known accurate reference and recording deviation over a fixed period of time. calibration values, including the number of seconds lost or gained in a given period, can be found in application note an934, ?timekeeper ? calibration.? this allows the designer to give the end user the abilit y to calibrate the clock as th e environment requires, even if the final product is packaged in a non-user serviceable enclosure. the designer could provide a simple utility that ac cesses the calibration byte. the second approach is better suited to a manufacturing environment, and involves the use of either the sqw pin (m41t62/63/64) or the irq /ft/out pin (M41T65). the sqw pin will toggle at 512hz wh en rs3 = '0,' rs2 = '1,' rs 1 = '1,' rs0 = '0,' sqwe = '1,' and st = '0.' alternatively, for the M41T65, the irq /ft/out pin will toggle at 512hz when ft and out bits = '1' and st = '0.' any deviation from 512hz indicates the degree and direction of oscillato r frequency shift at the test temperature. for example, a reading of 512.010124 hz would indicate a +20 ppm oscillator frequency erro r, requiring a ?10 (xx001010) to be loaded into the calibration byte for correction. note that setting or changi ng the calibration byte does not affect the frequency test or square wave output frequency.
clock operation m41t62/63/64/65 24/40 figure 20. crystal accuracy across temperature figure 21. calibration waveform ai07888 ?160 0 10203040506070 frequency (ppm) temperature c 80 ?10 ?20 ?30 ?40 ?100 ?120 ?140 ?40 ?60 ?80 20 0 ?20 = ?0.036 ppm/ c 2 0.006 ppm/ c 2 k ? f = k x (t ? t o ) 2 f t o = 25 c 5 c ai00594b normal positive calibration negative calibration
m41t62/63/64/65 clock operation 25/40 3.3 setting alarm clock registers address locations 0ah-0eh contain the alarm settings. the alarm can be configured to go off at a prescribed time on a specific month, date, hour, minute, or second, or repeat every year, month, day, hour, minute, or second. bits rpt5?rpt1 put the alarm in the repeat mode of operation. table 7 on page 25 shows the possible configurations. codes not listed in the table default to the once per second mode to quickly alert the user of an incorrect alarm setting. when the clock information matches the alarm clock settings based on the match criteria defined by rpt5?rpt1, the af (alarm flag) is set. if afe (alarm flag enable) is also set (m41t62/65), the alarm condition activates the irq /out or irq /ft/out pin. to disable the alarm, write '0' to the alarm date register and to rpt5?rpt1. note: if the address pointer is allowed to increment to the flag register address, an alarm condition will not cause the interrupt/flag to oc cur until the address po inter is moved to a different address. it should also be noted that if the last address written is the ?alarm seconds,? the address pointer will increment to the flag address, causing this situation to occur. the irq output is cleared by a read to the flags register as shown in figure 22 on page 25 . a subsequent read of the flags register is necessary to see that the value of the alarm flag has been reset to '0.' figure 22. alarm interrupt reset waveform table 7. alarm repeat modes rpt5 rpt4 rpt3 rpt2 rpt1 alarm setting 1 1 1 1 1 once per second 1 1 1 1 0 once per minute 1 1 1 0 0 once per hour 1 1 0 0 0 once per day 1 0 0 0 0 once per month 0 0 0 0 0 once per year alarm flag bit (af) 0fh 0eh 00h high-z ai08898 irq/out or irq/ft/out
clock operation m41t62/63/64/65 26/40 3.4 watchdog timer the watchdog timer can be used to detect an out-of-control microprocessor. the user programs the watchdog timer by setting the desired amount of time-out into the watchdog register, address 09h. bits bmb4-bmb0 store a binary multiplier and the three bits rb2-rb0 select the resolution where: 000=1/16 second (16hz); 001=1/4 second (4hz); 010=1 second (1hz); 011=4 seconds (1/4hz); and 100 = 1 minute (1/60hz). note: invalid combinations (101, 110, and 111) will not enable a watchdog time-out. setting the bmb4-bmb0 = 0 with any combination of rb2- rb0, other than 000, will result in an immediate watchdog time-out. the amount of time-out is then determined to be the multiplication of the five-bit multiplier value with the resolution. (for example: writing 00001110 in the watchdog register = 3*1 or 3 seconds). if the processor does not reset the timer within the specified period, the m41t6x sets the wdf (watchdog flag) and generates an interrupt on the irq pin (m41t62), or a watchdog output pulse (m41t63 and M41T65 only) on the wdo pin. the watchdog timer can only be reset by having the microprocessor perform a write of the watchdog register. the time-out period then starts over. should the watchdog timer time-out, any value may be written to the watchdog register in order to clear the irq pin. a value of 00h will disable the wa tchdog function until it is again programmed to a new value. a read of the flag s register will reset the watchdog flag (bit d7; register 0fh). the watchdog function is automatically disabled upon power-up, and the watchdog register is cleared. note: a write to any clock register will restart the watchdog timer. 3.5 watchdog output (wdo - m41t63/65 only) if the processor does not reset the watchdog time r within the specified period, the watchdog output (wdo ) will pulse low for t rec (see table 17 on page 34 ). this output may be connected to the reset input of the processor in order to generate a processor reset. after a watchdog time-out occurs, th e timer will remain disabled until such time as a new countdown value is written into the watchdog register. note: the crystal oscillator must be running for the wdo pulse to be available. the wdo output is an n-channel, open drain output driver (with i ol as specified in table 14 on page 32 ).
m41t62/63/64/65 clock operation 27/40 3.6 square wave output (m41t62/63/64) the m41t62/63/64 offers the user a programmable square wave function which is output on the sqw pin. rs3-rs0 bits located in 04h establish the square wave output frequency. these frequencies are listed in ta b l e 8 . once the selection of the sqw frequency has been completed, the sqw pin can be turned on and off under software control with the square wave enable bit (sqwe) located in register 0ah. the sqw output is an n-channel, open drain output driver for the m41t64, and a full cmos output driver for the m41t62/63. the initial power-up default for the sqw output is 32khz (except for m41t64, which defaults disabled). 3.7 full-time 32khz square wave output (m41t64) the m41t64 offers the user a special 32khz square wave function which is enabled on power-up to output on the f 32k pin as long as v cc 1.3v, and the oscillator is running (st bit = '0'). this function is available within on e second (typ) of initial power-up and can only be disabled by setting the 32ke bit to '0' or the st bit to '1.' if not used, the f 32k pin should be disconnected and allowed to float. table 8. square wave output frequency square wave bits square wave rs3 rs2 rs1 rs0 frequency units 0000none? 000132.768khz 00108.192khz 00114.096khz 01002.048khz 01011.024khz 0110512hz 0111256hz 1000128hz 100164hz 101032hz 101116hz 11008hz 11014hz 11102hz 11111hz
clock operation m41t62/63/64/65 28/40 3.8 century bits these two bits will increment in a binary fashio n at the turn of the century, and handle all leap years correctly. see table 10 on page 29 for additional explanation. 3.9 output driver pin (m41t62/65) when the ofie bit, afe bit, and watchdog register are not set to generate an interrupt, the irq /out pin becomes an output driver that reflects the contents of d7 of the calibration register. in other words, when d7 (out bit) is a '0,' then the irq /out pin will be driven low. note: the irq /out pin is an open drain which requires an external pull-up resistor. 3.10 oscillator stop detection if the oscillator fail (of) bit is internally set to a '1,' this indicates that the oscillator has either stopped, or was stopped for some period of time and can be used to judge the validity of the clock and date data. this bit will be set to '1' an y time the oscillator stops. in the event the of bit is found to be set to '1' at any time other than the initial power-up, the stop bit (st) should be written to a '1,' then immediately reset to '0.' this will restart the oscillator. the following conditions can cause the of bit to be set: the first time power is applied (defaults to a '1' on power-up). note: if the of bit cannot be written to '1' four (4) seconds after the initia l power-up, the stop bit (st) should be written to a '1,' then immediately reset to '0.' the voltage present on v cc or battery is insufficie nt to support oscillation. the st bit is set to '1.' external interference of the crystal if the oscillator fail interrupt enable bi t (ofie) is set to a '1,' the irq pin will also be activated. the irq output is cleared by resetting the ofie or of bit to '0' (not by reading the flag register). the of bit will remain set to '1' until written to logic '0.' the oscillator must start and have run for at least 4 seconds before attempting to reset the of bit to '0.' if the trigger event occurs during a power-down condit ion, this bit will be set correctly. 3.11 initial power-on defaults upon application of power to the device, the regi ster bits will initially power-on in the state indicated in ta b l e 9 .
m41t62/63/64/65 clock operation 29/40 table 9. initial power-on default values condition device st of ofie out ft afe sqwe 32ke rs3-1 rs0 watchdog initial power-up (1) 1. all other control bits power-up in an undetermined state. m41t62 0 1 0 1 n/a 0 1 n/a 0 1 0 m41t63 0 1 n/a n/a n/a n/a 1 n/a 0 1 0 m41t64 0 1 n/a n/a n/a n/a 0 1 0 1 0 M41T65 0 1 0 1 0 0 n/a n/a n/a n/a 0 table 10. century bits examples cb0 cb1 leap year? example (1) 1. leap year occurs every four years (f or years evenly divisible by four), except for y ears evenly divisible by 100. the only exceptions are those years evenly divisible by 400 (the y ear 2000 was a leap year, year 2100 is not). 00yes2000 0 1 no 2100 1 0 no 2200 1 1 no 2300
maximum rating m41t62/63/64/65 30/40 4 maximum rating stressing the device above the rating listed in the ?absolute maximum ratings? table may cause permanent damage to the device. these are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. refer also to the stmicroelectronics sure program and other relevant quality documents. table 11. absolute maximum ratings sym parameter conditions (1) 1. test conforms to jedec standard. value (2) 2. data based on characterization results, not tested in production. unit t stg storage temperature (v cc off, oscillator off) ?55 to 125 c v cc supply voltage ?0.3 to 5.0 v t sld (3) 3. reflow at peak temperature of 260c (total th ermal budget not to exceed 245c for greater than 30 seconds). lead solder temperature for 10 seconds 260 c v io input or output voltages ?0.2 to vcc+0.3 v i o output current 20 ma p d power dissipation 1 w v esd(hbm) electro-static discharge voltage (human body model) t a = 25c >1500 v v esd(rcdm) electro-static discharge voltage (robotic charged device model) t a = 25c >1000 v
m41t62/63/64/65 dc and ac parameters 31/40 5 dc and ac parameters this section summarizes the operating and measurement conditions, as well as the dc and ac characteristics of the device. the parameters in the following dc and ac characteristic tables are derived from tests performed under the measurement conditions listed in the relevant tables. designers should check that the operating conditions in their projects match the measurement conditions when using the quoted parameters. figure 23. ac measurement i/o waveform figure 24. crystal isolation example 1. substrate pad should be tied to v ss . table 12. operating and ac measurement conditions (1) 1. output hi-z is defined as the point where data is no longer driven. parameter m41t6x supply voltage (v cc ) 1.3v to 4.4v ambient operating temperature (t a ) ?40 to 85c load capacitance (c l ) 50pf input rise and fall times 5ns input pulse voltages 0.2v cc to 0.8 v cc input and output timing ref. voltages 0.3v cc to 0.7 v cc ai02568 0.8v cc 0.2v cc 0.7v cc 0.3v cc ai09127 crystal xi xo gnd local grounding plane (layer 2)
dc and ac parameters m41t62/63/64/65 32/40 table 13. capacitance symbol parameter (1)(2) 1. effective capacitance m easured with power supply at 3.6v ; sampled only, not 100% tested. 2. at 25c, f = 1mhz. min max unit c in input capacitance 7 pf c out (3) 3. outputs deselected. output capacitance 10 pf t lp low-pass filter input time constant (sda and scl) 50 ns table 14. dc characteristics sym parameter test condition (1) 1. valid for ambient operating temperature: t a = ?40 to 85c; v cc = 1.3v to 4.4v (except where noted). min typ max unit v cc (2) 2. oscillator start-up guaranteed at 1.5v only. operating voltage clock (3) 3. when using battery back-up, v cc fall time should not exceed 10mv/s. 1.0 4.4 v i 2 c bus (400khz) 1.3 4.4 v i cc1 supply current scl = 400khz (no load) 4.4v 100 a 3.6v 50 70 a 3.0v 35 a 2.5v 30 a 2.0v 20 a i cc2 supply current (standby) scl = 0hz all inputs v cc ? 0.2v v ss + 0.2v sqw off 4.4v 950 na 3.6v 375 700 na 3.0v @ 25c 350 na 2.0v @ 25c 310 na v il input low voltage ?0.2 0.3v cc v v ih input high voltage 0.7v cc v cc +0.3 v v ol output low voltage v cc = 4.4v, i ol = 3.0ma (cmos or open drain) 0.4 v v cc = 4.4v, i ol = 1.0ma (sqw, wdo , irq ) 0.4 v v oh output high voltage v cc = 4.4v, i oh = ?1.0ma (push-pull) 2.4 v pull-up supply voltage (open drain) irq /out, irq /ft/out, wdo , sqw (m41t64 only) 4.4 v i li input leakage current 0v v in v cc 1 a i lo output leakage current 0v v out v cc 1 a
m41t62/63/64/65 dc and ac parameters 33/40 table 16. oscillator characteristics figure 25. bus timing requirements sequence table 15. crystal electrical characteristics sym parameter (1)(2) 1. externally supplied if using the qfn16 package. stmicroelectroni cs recommends the citizen cfs-145 (1.5x5mm) and the kds dt-38 (3x8mm) for thru-hole, or the kds dmx-26s (3.2x8mm) for surface-mount, tuning fork-type quartz crystals. kds can be contacted at kouhou@kdsj.co.jp or http://www.kdsj.co.jp . citizen can be contacted at csd@citizen-america.com or http://www.citizencrystal.com . 2. load capacitors are integrated within the m41t6x. ci rcuit board layout consider ations for the 32.768khz crystal of minimum trace lengths and isolation from rf generating signal s should be taken into account. min typ max units f o resonant frequency 32.768 khz r s series resistance ( t a = ?40 to 70c, oscillator start-up at 2.0v) 75 (3)(4) 3. guaranteed by design. 4. r s (max) = 65k ? for t a = ?40 to 85c and oscillator start-up at 1.5v. k ? c l load capacitance 6 pf symbol parameter conditions min typ max unit v sta oscillator start voltage 10 seconds 1.5 v t sta oscillator start time v cc = 3.0v 1 s c g xin 12 pf c d xout 12 pf ic-to-ic frequency variation (1) 1. reference value. t a = 25c, v cc = 3.0v, cmj-145 (c l = 6pf, 32,768hz) manufactured by citizen. ?10 +10 ppm ai00589 sda p tsu:sto tsu:sta thd:sta sr scl tsu:dat tf thd:dat tr thigh tlow thd:sta tbuf s p
dc and ac parameters m41t62/63/64/65 34/40 table 17. ac characteristics sym parameter (1) 1. valid for ambient operating temperature: t a = ?40 to 85c; v cc = 1.3 to 4.4v (except where noted). min typ max units f scl scl clock frequency 0 400 khz t low clock low period 1.3 s t high clock high period 600 ns t r sda and scl rise time 300 ns t f sda and scl fall time 300 ns t hd:sta start condition hold time (after this period the first clock pulse is generated) 600 ns t su:sta start condition setup time (only relevant for a repeated start condition) 600 ns t su:dat (2) 2. transmitter must internally provi de a hold time to bridge the undefined region (300ns max) of the falling edge of scl. data setup time 100 ns t hd:dat data hold time 0 s t su:sto stop condition setup time 600 ns t buf time the bus must be free before a new transmission can start 1.3 s t rec watchdog output pulse width 96 98 ms
m41t62/63/64/65 package mechanical information 35/40 6 package mechanical information in order to meet environmental requirements, st offers these devices in ecopack ? packages. these packages have a lead-free second level interconnect. the category of second level interconnect is marked on the package and on the inner box label, in compliance with jedec standard jesd97. the maximum ratings related to soldering conditions are also marked on the inner box label. ecopack is an st trademark. ecopack specifications are available at: www.st.com. figure 26. qfn16 ? 16-lead, quad, flat package, no lead, 3x3mm body size, outline 1. drawing is not to scale. a3 a a1 e k k b ch d2 e2 l e d 1 2 ddd 3 qfn16-a c
package mechanical information m41t62/63/64/65 36/40 table 18. qfn16 ? 16-lead, quad, flat package, no lead, 3x3mm body size, mechanical data figure 27. qfn16 ? 16-lead, quad, flat package, no lead, 3x3mm, recommended footprint 1. dimensions shown are in millimeters (mm). symb mm inches typ min max typ min max a 0.90 0.80 1.00 0.035 0.032 0.039 a1 0.02 0.00 0.05 0.001 0.000 0.002 a3 0.20 ? ? 0.008 ? ? b 0.25 0.18 0.30 0.010 0.007 0.012 d 3.00 2.90 3.10 0.118 0.114 0.122 d2 1.70 1.55 1.80 0.067 0.061 0.071 e 3.00 2.90 3.10 0.118 0.114 0.122 e2 1.70 1.55 1.80 0.067 0.061 0.071 e0.50? ?0.020? ? k0.20? ?0.008? ? l 0.40 0.30 0.50 0.016 0.012 0.020 ddd ?0.08? ?0.003? ch ?0.33? ?0.013? n16 16 0.28 1.60 3.55 2.0 ai09126
m41t62/63/64/65 package mechanical information 37/40 figure 28. 32khz crystal + qfn16 vs. vsoj20 mechanical data 1. dimensions shown are in millimeters (mm). 1 xi 2 xo 3 4 ai11146 st qfn16 smt crystal vsoj20 2.9 2.9 1.5 3.2 6.0 0.2 7.0 0.3
part numbering m41t62/63/64/65 38/40 7 part numbering table 19. ordering information scheme for other options, or for more information on any aspect of this device, please contact the st sales office nearest you. example: m41t 62 q 6 f device family m41t device type and supply voltage 62 = v cc = 1.3v to 4.4v 63 = v cc = 1.3v to 4.4v 64 = v cc = 1.3v to 4.4v 65 = v cc = 1.3v to 4.4v package q = qfn16 (3mm x 3mm) temperature range 6 = ?40c to 85c shipping method for soic f = ecopack package, tape & reel
m41t62/63/64/65 revision history 39/40 8 revision history table 20. revision history date revision revision changes november 13, 2003 1.0 first issue 19-nov-03 1.1 add features, update characteristics ( figure 1 , figure 2 , figure 4 , figure 9 , figure 22 ; ta b l e 2 , ta b l e 3 , ta b l e 9 , ta bl e 1 1 , ta b l e 1 4 , ta b l e 1 7 ) 25-dec-03 2.0 reformatted; add crystal isolation, footprint ( figure 24 ) 14-jan-04 2.1 update characteristics ( figure 1 , figure 9 , figure 24 ; ta b l e 1 , ta b l e 3 . ta b l e 9 , ta b l e 1 4 ) 27-feb-04 2.2 update characteristics and mechanical dimensions ( figure 1 , figure 2 , figure 3 , figure 4 , figure 5 , figure 6 , figure 9 , figure 10 , figure 11 , figure 12 , figure 26 , figure 27 ; ta bl e 3 , ta b l e 4 , ta b l e 5 , ta b l e 6 , ta b l e 9 , ta b l e 1 1 , ta b l e 1 4 , ta b l e 1 8 ) 02-mar-04 2.3 update characteristics ( figure 7 , figure 8 , figure 11 ; ta b l e 2 , ta b l e 1 4 ) 26-apr-04 3.0 reformat and republish 13-may-04 4.0 update characteristics ( figure 5 , figure 6 , figure 7 , figure 8 , figure 24 , figure 27 ; ta bl e 1 1 , ta bl e 1 4 , ta bl e 1 5 ) 06-aug-04 5.0 correct diagrams; update characteristics ( figure 2 , figure 3 , figure 24 ; ta bl e 2 , ta b l e 1 4 , ta bl e 1 6 ) 11-oct-04 6.0 update characteristics ( ta bl e 1 1 , ta bl e 1 4 ) 18-jan-05 7.0 correct footprint dimensions ; update characteristics ( figure 2 , figure 7 , figure 11 , figure 13 , figure 27 ; ta b l e 1 , ta b l e 2 , ta b l e 5 , ta b l e 8 , ta b l e 9 , ta b l e 1 1 , ta b l e 1 2 , ta b l e 1 4 , ta bl e 1 5 , ta b l e 1 6 , ta bl e 1 7 ) 05-may-05 8.0 add package comparison and mechanical data (in feature summary on page 1 , figure 28 ) 31-oct-05 9.0 update: bus operating voltage, characteristics, add lead-free text ( figure 13 ; ta b l e 1 1 , ta bl e 1 2 , ta bl e 1 4 , ta bl e 1 7 , ta b l e 1 9 ) 30-nov-05 10.0 update esd:hbm rating, crystal characteristics ( ta b l e 1 1 , ta b l e 1 5 ) 22-aug-2006 11 changed document to new template; small text changes for feature summary on page 1
m41t62/63/64/65 40/40 please read carefully: information in this document is provided solely in connection with st products. stmicroelectronics nv and its subsidiaries (?st ?) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described he rein at any time, without notice. all st products are sold pursuant to st?s terms and conditions of sale. purchasers are solely responsible for the choice, selection and use of the st products and services described herein, and st as sumes no liability whatsoever relating to the choice, selection or use of the st products and services described herein. no license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. i f any part of this document refers to any third party products or services it shall not be deemed a license grant by st for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoev er of such third party products or services or any intellectual property contained therein. unless otherwise set forth in st?s terms and conditions of sale st disclaims any express or implied warranty with respect to the use and/or sale of st products including without limitation implied warranties of merchantability, fitness for a parti cular purpose (and their equivalents under the laws of any jurisdiction), or infringement of any patent, copyright or other intellectual property right. unless expressly approved in writing by an authorized st representative, st products are not recommended, authorized or warranted for use in milita ry, air craft, space, life saving, or life sustaining applications, nor in products or systems where failure or malfunction may result in personal injury, death, or severe property or environmental damage. st products which are not specified as "automotive grade" may only be used in automotive applications at user?s own risk. resale of st products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by st for the st product or service described herein and shall not create or extend in any manner whatsoev er, any liability of st. st and the st logo are trademarks or registered trademarks of st in various countries. information in this document supersedes and replaces all information previously supplied. the st logo is a registered trademark of stmicroelectronics. all other names are the property of their respective owners. ? 2006 stmicroelectronics - all rights reserved stmicroelectronics group of companies australia - belgium - brazil - canada - china - czech republic - finland - france - germany - hong kong - india - israel - ital y - japan - malaysia - malta - morocco - singapore - spain - sweden - switzerland - united kingdom - united states of america www.st.com

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