Microchip | MCP7940N-I/SN

The MCP7940N-I/SN is a Low-Power, Low-Cost I2C Real-Time Clock, uses digital timing compensation for an accurate clock, a programmable output control for versatility, and a power sense circuit that automatically switches to the backup supply.

It tracks time using several internal registers. For communication, it uses the I2C bus. The device is fully accessible through the serial interface while VCC is between 1.8 V and 5.5 V, but can operate down to 1.3 V for timekeeping and SRAM retention only.

Features:

• Real-Time Clock (RTC), Battery Backed
• Dual alarm with single output
• On-Chip digital trimming/calibration
• Range -127 to +127 ppm
• Resolution 1 ppm
• Programmable open-drain output control
• CLKOUT with 4 selectable frequencies
• 64 Bytes SRAM, battery backed
• Power-fail time-stamp for Battery Switchover
• Low power CMOS technology
• 100 kHz and 400 kHz compatibility