DS1689 Datasheet, PDF (30/32 Pages) Dallas Semiconductor – 3-Volt/5-Volt Serialized Real-Time Clock with NV RAM Control

NOTES:
1. All voltages are referenced to ground.
DS1689/DS1693
2. Typical values are at 25°C and nominal supplies.
3. Outputs are open.
4. Value for voltage and currents is from the V_CCI input pin to the V_CCO pin.
5. Write protection trip point occurs during power fail prior to switchover from V_CC to V_BAT.
6. Value for voltage and currents is from the V_BAT input pin to the V_CCO pin.
7. Applies to the AD0-AD7 pins, and the SQW pin when each is in a high impedance state.
8. The IRQ pin is open drain.
9. Measured with a load of 50 pF + 1 TTL gate.
10. Wakeup kickstart timeout generated only when the oscillator is enabled and the countdown chain is
not reset.
11. V_SW is determined by the larger of V_BAT and V_BAUX.
12. Z_CE is an average input to output impedance as the input is swept from GND to V_CCI and less than
4 mA is forced through Z_CE.
13. The DS1693 will keep time to an accuracy of ±1 minute per month during data retention time for the
period of t_DR.
14. t_DR is the amount of time that the internal battery can power the internal oscillator and internal
registers of the DS1693. As such, t_DR is specified with V_CCO floating. If V_CCO is powering an external
SRAM, an auxiliary battery must be connected to the V_BAUX pin. The auxiliary battery should be sized
such that it can power the external SRAM for the t_DR period.
15. The CEI pin has an internal pull-up of 60 kW.
16. The PSEL pin has an internal pull-down of 60 kW.
17. For industrial grade parts, I_BAT (with OSC off) limit increases to 250 nA.
18. Real-Time Clock Modules can be successfully processed through conventional wave-soldering
techniques as long as temperature exposure to the lithium energy source contained within does not
exceed +85°C. Post-solder cleaning with water washing techniques is acceptable, provided that
ultrasonic vibration is not used.
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