DS1644 Maxim, DS1644 Datasheet - Page 12

• 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

DS1644 28-PIN PACKAGE
DS1644P
NOTE FOR THE PowerCap VERSION:
a.
b.
12 of 14
MAXIM RECOMMENDS THAT PowerCap MODULE BASES
EXPERIENCE ONE PASS THROUGH SOLDER REFLOW
ORIENTED WITH THE LABEL SIDE UP (“LIVE - BUG”).
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 REFLOWS AND USE A SOLDER WICK
TO REMOVE SOLDER.
PKG
DIM
A IN.
MM
B IN.
MM
C IN.
MM
D IN.
MM
E IN.
MM
F IN.
MM
G IN.
MM
H IN.
MM
J IN.
MM
K IN.
MM
PKG
DIM
A
B
C
D
E
F
G
28-PIN
MIN
1.470
37.34
0.715
18.16
0.335
8.51
0.075
1.91
0.015
0.38
0.140
3.56
0.090
2.29
0.590
14.99
0.010
0.25
0.015
0.38
INCHES
MIN
0.920
0.980
-
0.052
0.048
0.015
0.025
MAX
1.490
37.85
0.740
18.80
0.365
9.27
0.105
2.67
0.030
0.76
0.180
4.57
0.110
2.79
0.630
16.00
0.018
0.45
0.025
0.64
NOM
0.925
0.985
-
0.055
0.050
0.020
0.027
DS1644/DS1644P
MAX
0.930
0.990
0.080
0.058
0.052
0.025
0.030