DS1543 datasheet(16/17 Pages) DALLAS

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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 VPF.

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 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.

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.

DS1543 Datasheet(PDF) 16 Page - Dallas Semiconductor