Timekeeping Chip

The DS1672 Low-Voltage Serial Timekeeping Chip is an ultra-low voltage timekeeper with power monitoring circuitry and power-fail switches. The single-chip combination enables more efficient and cost-effective board designs. The chip offers the option of an automatic switch to trickle charging. Communicating with a processor over a 2-wire interface, the chip's 32-bit counter counts seconds, from which a software algorithm computes time of day, week, month and year. Silicon clocks are used in all kinds of computers and computerized systems; the device's low-voltage operation is critical to battery-operated equipment such as cell phones, GPS devices, palm-size computers and laptops.

The device monitors power supplies for out-of-tolerance voltages. When an under-supply condition occurs, it write-protects timekeeping data registers, resets the processor, and switches to backup power to prevent data corruption. On low-power mode the oscillator maintains timekeeping down to 1.3V, consuming less than 200 nanoamps of current. When power supplies return to normal levels, the device holds the processor in reset for 250 ms while operating conditions stabilize.

The device is an ideal timekeeper for any electronic system, instrument or machine that operates in the 2.0V to 3.3V ranges and requires protection from power failure. Different versions are available for 2.0V, 3.0V, and 3.3V environments, with 8-pin DIP, SOIC and µSOP package options.

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