Microchip Technology MCP7940N-I/SN

Description
The MCP7940N series of low-power Real-Time Clocks (RTCs) utilizes digital timing compensation for accurate timekeeping. It features a programmable output control for versatility and a power sense circuit that automatically switches to the backup supply. Using a low-cost 32.768 kHz crystal, it tracks time using internal registers and communicates via the I²C™ bus.
The clock/calendar automatically adjusts for months with fewer than 31 days, including leap year corrections. It operates in either 24-hour or 12-hour format with an AM/PM indicator and settable alarms to the second, minute, hour, day of the week, date, or month. The programmable CLKOUT generates frequencies of 32.768, 8.192, 4.096 kHz, and 1 Hz from the external crystal.
The device is fully accessible through the serial interface while Vcc is between 1.8V and 5.5V, but can operate down to 1.3V for timekeeping and SRAM retention only.

Features
64 Bytes SRAM
Real-Time Clock/Calendar (RTCC) with battery backup
Dual alarm with single output
On-Chip Digital Trimming/Calibration
Programmable Open-Drain Output Control
64 Bytes SRAM, Battery Backed
Automatic Vcc Switchover to VBAT Backup Supply
Power-Fail Time-Stamp for Battery Switchover
Low-Power CMOS Technology
100 kHz and 400 kHz Compatibility
ESD Protection >4,000V
Pb-Free and RoHS Compliant

Applications
Timekeeping and date tracking
Alarm and event scheduling
Data logging and timestamping
Industrial control and automation
Consumer electronics
Medical devices