DS1643/DS1643P
AC TEST CONDITIONS
Output Load:
Input Pulse Levels:
100 pF + 1TTL Gate
0.0 to 3.0 Volts
Timing Measurement Reference Levels:
Input: 1.5V
Output: 1.5V
Input Pulse Rise and Fall Times: 5 ns
NOTES:
1. Voltages are referenced to ground.
2. Typical values are at 25°C and nominal supplies.
3. Outputs are open.
4. The CE2 control signal functions exactly the same as the CE signal except that the logic levels for
active and inactive levels are opposite.
5. Data retention time is at 25°C.
6. Each DS1643 has a built-in switch that disconnects the lithium source until VCC is first applied by the
user. The expected tDR is defined for DIP modules as a cumulative time in the absence of VCC starting
from the time power is first applied by the user.
7. Real-Time Clock Modules (DIP) can be successfully processed through conventional wave-soldering
techniques as long as temperatures 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.
In addition, for the PowerCap:
a. Dallas Semiconductor recommends that PowerCap Module bases experience one pass through
solder reflow oriented with the label side up (“live-bug”).
b. Hand soldering and touch-up: Do not touch or apply the soldering iron to leads for more than 3
seconds. To solder, apply flux to the pad, heat the lead frame pad and apply solder. To remove the
part, apply flux, heat the lead frame pad until the solder reflow and use a solder wick to remove
solder.
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