M41T93_08 Datasheet, PDF (1/51 Pages) STMicroelectronics – Serial SPI bus RTC with battery switchover

M41T93
Serial SPI bus RTC with battery switchover
Features
■ Ultra-low battery supply current of 365 nA
■ Factory calibrated accuracy ±5 ppm
guaranteed after 2 reflows (SOX18)
– Much better accuracies achievable using
built-in programmable analog and digital
calibration circuits
■ 2.0 V to 5.5 V clock operating voltage
■ Counters for tenths/hundredths of seconds,
seconds, minutes, hours, day, date, month,
year, and century
■ Automatic switchover and reset output circuitry
(fixed reference)
– M41T93S: V_CC = 3.0 V to 5.5 V
(2.85 V ≤ V_RST ≤ 3.00 V)
– M41T93R: V_CC = 2.7 V to 5.5 V
(2.55 V ≤ V_RST ≤ 2.70 V)
– M41T93Z: V_CC = 2.38 V to 5.50 V
(2.25 V ≤ V_RST ≤ 2.38 V)
■ Compatible with SPI bus serial interface
(supports SPI mode 0 [CPOL = 0, CPHA = 0])
■ Programmable alarm with interrupt function
(valid even during battery back-up mode)
■ Optional 2^nd programmable alarm available
■ Square wave output (defaults to 32 kHz on
power-up)
■ 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 80 µA
■ Oscillator stop detection
■ Battery or SuperCap™ backup
■ Operating temperature of –40°C to +85°C
QFN16, 4 mm x 4 mm (QA)
18
1
SOX18 (MY, 18-pin, 300 mil SOIC
with embedded crystal)
■ Package options include:
– a 16-lead QFN or an 18-lead embedded
crystal SOIC
■ RoHS compliance: lead-free components are
compliant with the RoHS directive
August 2008
Rev 4
1/51
www.st.com
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