Rainbow Electronics DS1543 - Manual (Page 16)

DS1543
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AC TEST CONDITIONS
Output Load: 100 pF + 1TTL Gate
Input Pulse Levels: 0.0 to 3.0V
Timing Measurement Reference Levels:
Input: 1.5V
Output: 1.5V
Input Pulse Rise and Fall Times: 5 ns
NOTES:
1. Voltage referenced to ground.
2. Typical values are at 25
°
C and nominal supplies.
3. Outputs are open.
4. Battery switch over occurs at the lower of either the battery voltage or V
PF
.
5. The IRQ /FT and RST outputs are open-drain.
6. Data retention time is at 25
°
C.
7. Each DS1543 has a built-in switch that disconnects the lithium source until V
CC
is first applied by the
user. The expected t
DR
is defined for DIP modules as a cumulative time in the absence of V
CC
starting
from the time power is first applied by the user.
8. Real Time Clock Modules (DIP) 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.
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.