描述 Description

The M41T8x are low power Serial I2C Real Time Clocks with a built-in 32.768kHz oscillator (external crystal-controlled for the QFN16 and SO8 packages, embedded crystal for the SOX18 package). Eight bytes of the Register Map (see Table 2 on page 23) are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. An additional 17 bytes of the Register Map provide status/control of the two Alarms, Watchdog, 8-bit Counter, and Square Wave functions. An additional seven bytes are made available as user SRAM.

特性 Features

■ 2.0 to 5.5V clock operating voltage

■ Ultra-low battery supply current of 365nA

■ Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century

■ Programmable clock calibration (analog and digital)

■ Automatic switchover and reset output circuitry (fixed reference)

– M41T83S

VCC = 3.00V to 5.50V

(2.85V ≤ VRST ≤ 3.00V)

– M41T83R

VCC = 2.70V to 5.50V

(2.55V ≤ VRST ≤ 2.70V)

– M41T83Z

VCC = 2.38V to 5.50V

(2.25V ≤ VRST ≤ 2.38V)

■ Serial interface supports I2C Bus (400kHz protocol)

■ Programmable alarm with interrupt function (valid even during battery back-up mode)

■ Optional 2nd programmable alarm available

■ Square wave output defaults to 32KHz on power-up (M41T83 only)

■ RESET (RST) output

■ Watchdog timer

■ Programmable 8-bit counter/timer

■ 7 bytes of battery-backed user SRAM

■ Battery low flag

■ Power-down time stamp (HT bit)

■ Low operating current of 80μA

■ Oscillator stop detection

■ Battery or Super-cap? back-up

■ Operating temperature of –40°C to 85°C

■ Package options include:

– a 16-lead QFN (M41T83),

– an 18-lead embedded crystal SOIC (M41T83), or

– an 8-lead SOIC (M41T82)

■ RoHS compliance: lead-free components are compliant with the RoHS directive.