The DS1687-5+ is an RTC (Real Time Clock) IC manufactured by Analog Devices. It is a low power, full-featured clock/calendar and incorporates both 64-bit and 128-bit protected battery backup SRAM. It also offers programmable output clock signals such as a 256Hz square wave, 32kHz period wave, 1 Hz wave and a 1/128Hz wave. It features a ±2ppm accuracy and is available in a tiny 8-pin MSOP package. It supports low-voltage battery backup, extended temperature range from -40°C to +85°C, and a wide commercial supply voltage range from 2.7V to 5.5V. Furthermore, it includes many features such as programmable switchover points for seasonal time change, battery-backed clock accumulation, power-on reset, two alarms, five programmable output drivers and advanced power management features. This clock is the ideal choice for battery-backed applications such as medical equipment, security systems, digital appliances and industrial controllers.