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
DC and AC parameters M41T62, M41T63, M41T64, M41T65
34/44 DocID10397 Rev 20
Table 15. Crystal electrical characteristics
Sym Parameter
(1)(2)
Min Typ Max Units
fO
Resonant frequency - 32.768 kHz
RS
Series resistance (T
A
= –40 to 70 °C, oscillator startup at 2.0 V) - 75
(3)(4)
kΩ
C
L
Load capacitance - 6 pF
1. For the QFN16 package, user-supplied external crystals are required. The 6 and 7 pF crystals listed in
Table 16 below have been evaluated by ST and have been found to be satisfactory for use with the M41T6x
series RTC.
2. Load capacitors are integrated within the M41T6x. Circuit board layout considerations for the 32.768 kHz
crystal of minimum trace lengths and isolation from RF generating signals should be taken into account.
3. Guaranteed by design.
4. R
S (max)
= 65 kΩ for T
A
= –40 to 85 °C and oscillator startup at 1.5 V.
Table 16. Crystals suitable for use with M41T6x series RTCs
Vendor Order number Package
Manufacturer’s specifications
ESR
max
Temp.
range (°C)
Rated
tolerance
at 25 °C
Rated
load
cap.
Citizen CMJ206T-32.768KDZB-UB
8.3 x 2.5 mm
leaded SMT
50 kΩ –40/+85 ±20 ppm 6 pF
Citizen CM315-32.768KDZY-UB 3.2 x 1.5 x 0.9 mm SMT 70 kΩ –40/+85 ±20 ppm 7 pF
Ecliptek E4WCDA06-32.768K
(1)
2.0 x 6.0 mm thru-hole 50 kΩ –10/+60 ±20 ppm 6 pF
Ecliptek E5WSDC 07 - 32.768K 7 x 1.5 x 1.4 mm SMT 65 kΩ –40/+85 ±20 ppm 7 pF
ECS ECS-.327-6-17X-TR 3.8 x 8.5 x 2.5 mm SMT 50 kΩ –40/+85 ±20 ppm 6 pF
ECS ECS-.327-7-34B-TR 3.2 x 1.5 x 0.9 mm SMT 70 kΩ –40/+85 ±20 ppm 7 pF
ECS ECS-.327-7-38-TR 7 x 1.5 x 1.4 mm SMT 65 kΩ –40/+85 ±20 ppm 7 pF
Epson MC-146 32.7680KA-AG: ROHS
(2)
7 x 1.5 x 1.4 mm SMT 65 kΩ –40/+85 ±20 ppm 7 pF
Fox 298LF-0.032768-19 1.5 x 5.0 mm thru-hole 50 kΩ –20/+60 ±20 ppm 6 pF
Fox 299LF-0.032768-37 2.0 x 6.0 mm thru-hole 50 kΩ –20/+60 ±20 ppm 6 pF
Fox 414LF-0.032768-12 3.8 x 8.5 x 2.5 mm SMT 50 kΩ –40/+85 ±20 ppm 6 pF
Fox 501LF-0.032768-5 7 x 1.5 x 1.4 mm SMT 65 kΩ –40/+85 ±20 ppm 7 pF
Micro
Crystal
MS3V-T1R 32.768KHZ 7PF 20PPM
6.7 x 1.4 mm
leaded SMT
65 kΩ –40/+85 ±20 ppm 7 pF
Pletronics SM20S - 32.768K - 6pF 3.8 x 8.5 x 2.5 mm SMT 50 kΩ –40/+85 ±20 ppm 6 pF
Seiko SSPT7F-7PF20PPM 7 x 1.5 x 1.4 mm SMT 65 kΩ –40/+85 ±20 ppm 7 pF
Seiko VT200F-6PF20PPM 2.0 x 6.0 mm thru-hole 50 kΩ –10/+60 ±20 ppm 6 pF
1. ST has been informed that this crystal has been terminated by the vendor.
2. Epson MC-146 32.7680KA-E: ROHS is 6 pF version.