Not For New Design

This is information on a product still in production but not recommended for new designs.

May 2008

Rev 9

1/25

1

M41T00

Serial real-time clock

Features

month, years, and century

capacitance (12.5 pF) providing exceptional

oscillator stability and high crystal series

resistance operation

protocol)

(typ at 3 V)

(for 3 V application select M41T00S datasheet)

crystal deviation due to temperature

Description

The M41T00 is a low power serial real time clock

with a built-in 32.768 kHz oscillator (external

crystal controlled). 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 M41T00 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 5 years

with a 50 mA/h 3 V lithium cell (see Section 2.10:

Data retention mode for AC/DC characteristics).

The M41T00 is supplied in 8-lead plastic small

outline package.

8

1

SO8(M)

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