Rochester Electronics Clock/Timing - Real Time Clocks DS1743P-70+

The DS1743P-70+ is a year-2000-compliant real-time clock and nonvolatile static RAM integrated into a 34-pin PowerCap module. It features an 8k x 8 SRAM capacity and includes a built-in lithium energy source, ensuring data retention for over 10 years without power. The device provides a bytewide interface for accessing clock registers, which store time data in BCD format, including century, year, month, date, day, hours, minutes, and seconds, with automatic leap year compensation valid through 2099. The DS1743P-70+ incorporates power-fail control circuitry that prevents data loss during power fluctuations by disabling access when the supply voltage falls below a specified threshold. The lithium battery is electrically disconnected until the device is powered for the first time, preserving its freshness. This module is designed for surface mounting and requires a separate PowerCap for the crystal and battery, which can be installed after soldering to avoid damage from high temperatures. The device is UL recognized to prevent charging of the internal lithium battery, making it suitable for applications requiring reliable timekeeping and data retention.