General Description
The DS1374 is a 32-bit binary counter designed to continuously count time in seconds. An additional counter gen erates a periodic alarm or serves as a watchdog timer. If disabled, this counter can be used as 3 bytes of non volatile (NV) RAM. Separate output pins are provided for an interrupt and a square wave at one of four selectable frequencies. A precision temperature-compensated refer ence and comparator circuit monitor the status of VCC to detect power failures, provide a reset output, and auto matically switch to the backup supply when necessary. Additionally, the reset pin is monitored as a pushbutton input for externally generating a reset. The device is programmed serially through an I2C serial interface.

FEATUREs
♦ 32-Bit Binary Counter
♦ Second Binary Counter Provides Time-of-Day
Alarm, Watchdog Timer, or NV RAM
♦ Separate Square-Wave and Interrupt Output Pins
♦ I2C Serial Interface
♦ Automatic Power-Fail Detect and Switch Circuitry
♦ Single-Pin Pushbutton Reset Input/Open-Drain
Reset Output
♦ Low-Voltage Operation
♦ Trickle-Charge Capability
♦ -40°C to +85°C Operating Temperature Range
♦ 10-Pin µSOP, 16-Pin SO
♦ Available in a Surface-Mount Package with an
Integrated Crystal (DS1374C)
♦ Underwriters Laboratories (UL) Recognized