DS1643 Datasheet, PDF (12/17 Pages) Dallas Semiconductor – Nonvolatile Timekeeping RAM

DS1643/DS1643P
AC TEST CONDITIONS
Output Load: 100pF + 1TTL Gate
Input Pulse Levels: 0 to 3.0V
Timing Measurement Reference Levels:
Input: 1.5V
Output: 1.5V
Input Pulse Rise and Fall Times: 5ns
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 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.
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.
PACKAGE INFORMATION
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
28 EDIP
MDF28+2
21-0245
34 PowerCap
PC1+2
21-0246
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