M41T56_11 STMICROELECTRONICS [STMicroelectronics], M41T56_11 Datasheet - Page 5

• Manufacturer Part Number: M41T56_11
• Description: Serial real-time clock (RTC) with 56 bytes NVRAM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M41T56
1
Description
The M41T56 is a low-power, serial real-time clock (RTC) with 56 bytes of NVRAM. A built-in
32,768 Hz oscillator (external crystal controlled) and the first 8 bytes of the RAM are used
for the clock/calendar function and are configured in binary coded decimal (BCD) format.
Addresses and data are transferred serially via a two-line, bidirectional bus. The built-in
address register is incremented automatically after each WRITE or READ data byte.
The M41T56 clock has a built-in power sense circuit which detects power failures and
automatically switches to the battery supply during power failures. The energy needed to
sustain the RAM and clock operations can be supplied from a small lithium coin cell.
Typical data retention time is in excess of 10 years with a 50 mAh, 3 V lithium cell. The
M41T56 is supplied in an 8-lead plastic SOIC package.
Figure 1.
Logic diagram
OSCI
SCL
Doc ID 6104 Rev 9
V CC
V SS
M41T56
V BAT
OSCO
SDA
FT/OUT
Description
AI02304B
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