DS1644 Maxim, DS1644 Datasheet - Page 11

• Manufacturer Part Number: DS1644
• Description: The DS1644 is a 32k x 8 nonvolatile static RAM with a full function real time clock, which are both accessible in a byte-wide format
• Manufacturer: Maxim

NOTES:
1. All voltages are referenced to ground.
2. Typical values are at 25C and nominal supplies.
3. Outputs are open.
4. Data retention time is at 25C and is calculated from the date code on the device package. The date
5. t
6. t
7. Real-Time Clock Modules (DIP) can be successfully processed through conventional wave-soldering
PACKAGE INFORMATION
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a
different suffix character, but the drawing pertains to the package regardless of RoHS status.
code XXYY is the year followed by the week of the year in which the device was manufactured. For
example, 9225 would mean the 25
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 version:
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
AH1
AH2
solder reflow oriented with the label side up (“live - bug”).
3 (three) 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.
, t
, t
PACKAGE TYPE
DH1
DH2
34 PWRCP
28 EDIP
are measured from
are measured from
WE
CE
going high.
going high.
th
week of 1992.
PACKAGE CODE
MDF28+3
PC2+2
11 of 14
DOCUMENT NO.
21-0245
21-0246
DS1644/DS1644P
Note