Datasheet
Table Of Contents
- Table 1. Device summary
- 1 Description
- Figure 1. M41T62 logic diagram
- Figure 2. M41T63 logic diagram
- Figure 3. M41T64 logic diagram
- Figure 4. M41T65 logic diagram
- Figure 5. M41T62 connections
- Figure 6. M41T63 connections
- Figure 7. M41T64 connections
- Figure 8. M41T65 connections
- Table 2. Signal names
- Figure 9. M41T62 block diagram
- Figure 10. M41T63 block diagram
- Figure 11. M41T64 block diagram
- Figure 12. M41T65 block diagram
- Figure 13. Hardware hookup for SuperCap™ backup operation
- 2 Operation
- 3 Clock operation
- 3.1 RTC registers
- 3.2 Calibrating the clock
- 3.3 Setting alarm clock registers
- 3.4 Watchdog timer
- 3.5 Watchdog output (WDO - M41T63/65 only)
- 3.6 Square wave output (M41T62/63/64)
- 3.7 Full-time 32 KHz square wave output (M41T64)
- 3.8 Century bits
- 3.9 Leap year
- 3.10 Output driver pin (M41T62/65)
- 3.11 Oscillator stop detection
- 3.12 Initial power-on defaults
- 4 Maximum ratings
- 5 DC and AC parameters
- Table 12. Operating and AC measurement conditions
- Figure 25. AC measurement I/O waveform
- Figure 26. Crystal isolation example
- Table 13. Capacitance
- Table 14. DC characteristics
- Table 15. Crystal electrical characteristics
- Table 16. Crystals suitable for use with M41T6x series RTCs
- Table 17. Oscillator characteristics
- Figure 27. Bus timing requirements sequence
- Table 18. AC characteristics
- 6 Package mechanical information
- Figure 28. QFN16 - 16-pin, quad, flat package, no-lead, 3 mm x 3 mm body size, outline
- Table 19. QFN16 - 16-pin, quad, flat package, no-lead, 3 mm x 3 mm body size, mechanical data
- Figure 29. QFN16 - 16-pin, quad, flat package, no-lead, 3 x 3 mm, recommended footprint
- Figure 30. LCC8 - 8-pin, 1.5 mm x 3.2 mm leadless chip carrier, outline
- Table 20. LCC8 - 8-pin, 1.5 mm x 3.2 mm leadless chip carrier, mechanical data
- Figure 31. LCC8 - 8-pin, 1.5 mm x 3.2 mm leadless chip carrier, recommended footprint
- Figure 32. Carrier tape for QFN16 3 mm x 3 mm package
- Table 21. Carrier tape dimensions for QFN16 3 mm x 3 mm package
- Figure 33. Carrier tape for LCC8 1.5 mm x 3.2 mm package
- Figure 34. Reel schematic
- Table 22. Reel dimensions for 12 mm carrier tape - QFN16 and LCC8 packages
- 7 Part numbering
- 8 Revision history
Description M41T62, M41T63, M41T64, M41T65
6/44 DocID10397 Rev 20
1 Description
The M41T6x is a low-power serial real-time clock (RTC) with a built-in 32.768 kHz oscillator.
Eight registers are used for the clock/calendar function and are configured in binary-coded
decimal (BCD) format. An additional eight registers provide status/control of alarm, 32 KHz
output, calibration, and watchdog functions. Addresses and data are transferred serially via
a two-line, bidirectional 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), 32 KHz output (M41T62/63/64), 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 two very small packages: a tiny, 3 mm x 3 mm 16-pin QFN which
requires a user-supplied 32 KHz crystal, and an ultra-small 1.5 mm x 3.2 mm LCC with
embedded crystal - no external crystal is required.
Figure 1. M41T62 logic diagram
1. Open drain.
2. Defaults to 32 KHz on power-up.
3. Not bonded on LCC package.
SCL
V
CC
M41T62
V
SS
SDA
IRQ/OUT
(1)
SQW
(2)
XI
(3)
XO
(3)
AI09103