DS1632 Datasheet, PDF (2/6 Pages) Dallas Semiconductor – PC Power-Fail and Reset Controller

DS1632
power-up and via pushbutton input, power-fail status signals for the processor, and low battery warning
signals. The DS1632 is capable of detecting power failure at both the 5% and 10% power supply
tolerances, and the reset pulse width can be set for either 95 ms or 190 ms. The device is designed to
connect directly to popular laptop and notebook chip sets which eliminates the need for discrete
components and reduces cost.
BLOCK DIAGRAM Figure 1
OPERATION - CRYSTAL OSCILLATOR SECTION
The DS1632 crystal oscillator is designed to be hooked directly to a 32.768 kHz crystal. By using the
Daiwa Part No. DT26S, Seiko Part No. DS-VT-200 or equivalent, the oscillator will be accurate enough
to run a real time clock to within ±2 minutes per month. If another crystal is to be selected, it should have
a specified load capacitance (C_L) of 6 pF. The crystal oscillator will run as long as either V_CC or V_BAT is
present, providing that V_BAT is greater than 2.3V. The oscillator output provides a rail to rail swing with
regards to V_CC or V_BAT, whichever is greater. The crystal oscillator is also used internally as a time base.
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