New Timekeeper IC Combines Processor Reset And Back-Up Switching Circuitry

Touted as the first ultra-low voltage timekeeper with sophisticated power monitoring circuitry and power-fail switches, the DS1672 Low-Voltage Serial Timekeeping chip is said to enable more efficient and cost-effective board designs. It also offers the option of an automatic switch for trickle charging. Communicating with a processor over a 2-wire interface, the DS1672's 32-bit counter counts seconds, from which a software algorithm computes time of day, week, month and year.
The timekeeper monitors power supplies for out-of-tolerance voltage and, when an under-supply condition occurs, it write-protects timekeeping data registers, resets the processor, and switches to backup power to prevent data corruption. In low-power mode, timekeeping is maintained down to 1.3V, with less than 200 nA being consumed. Different versions of the timekeeper are available for 2.0V, 3.0V and 3.3V environments, with 8-pin DIP, SOIC and mSOP packages also offered as options. Price varies by packaging from $1.18 each/1,000 for DIP and SOIC to $1.35 each for mSOP packages.