M41T01 Datasheet, PDF (1/24 Pages) STMicroelectronics – Automatic switchover and deselect circuitry

M41T01
Low-power serial real-time clock (RTC)
with built-in battery switchover circuit
Datasheet - production data
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Features
 2.0 to 5.5 V clock operating voltage
 Counters for seconds, minutes, hours, day,
date, month, years, and century
 Software clock calibration
 Automatic switchover and deselect circuitry
 Ultra-low battery supply current of 800 nA
 Low operating current of 300 μA
 Battery and capacitor backup
 Battery backup not recommended for 3.0 V
applications (capacitor backup only)
 Operating temperature of –40 to 85 °C
 Automatic leap year compensation
Description
The M41T01 is a low-power serial real-time clock
(RTC). The built-in 32.768 kHz oscillator circuit
works with an external crystal and does not need
any load capacitors.
The M41T01 clock has a built-in power sense
circuit which detects power failures and
automatically switches to the battery supply
during power failures. Eight 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 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 5 years
with a 50 mA/h 3 V lithium cell. The M41T01 is
supplied in an 8-lead plastic small outline
package.
October 2013
This is information on a product in full production.
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