DS1744-70+ Dallas Semiconductor, DS1744-70+ Datasheet - Page 15

• Manufacturer Part Number: DS1744-70+
• Description: Nonvolatile timekeeping RAM, with Crystal, Power-Fail & Lithium Battery, DIP-28
• Manufacturer: Dallas Semiconductor

Specifications of DS1744-70+

• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

AC TEST CONDITIONS
Output Load: 50pF + 1TTL Gate
Input Pulse Levels: 0 to 3.0V
Timing Measurement Reference Levels:
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) Battery switchover occurs at the lower of either the battery terminal voltage or V
5) Data-retention time is at +25°C.
6) Each DS1744 has a built-in switch that disconnects the lithium source until the user first applies V
7) RTC modules (DIP) can be successfully processed through conventional wave-soldering techniques as
8) t
9) t
The expected t
in the absence of V
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:
AH1
AH2
Input: 1.5V
Output: 1.5V
a. ) Dallas Semiconductor recommends that PowerCap module bases experience one pass through
b.) Hand soldering and touch-up: Do not touch or apply the soldering iron to leads for more than
, t
, t
DH1
DH2
solder reflow oriented with the label side up (“live-bug”).
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 reflows, and use a solder
wick to remove solder.
are measured from WE going high.
are measured from CE going high.
DR
is defined for DIP modules and assembled PowerCap modules as a cumulative time
CC
starting from the time power is first applied by the user.
15 of 20
PF
.
CC
.