
DS1556 1M, Nonvolatile, Y2K-Compliant Timekeeping RAM
2 of 18
PIN DESCRIPTION
A0–A16
- Address Input
DQ0–DQ7
- Data Input/Outputs
IRQ/FT
- Interrupt, Frequency Test Output (Open Drain)
RST
- Power-On Reset Output (Open Drain)
CE
- Chip Enable
OE
- Output Enable
WE
- Write Enable
VCC
- Power Supply Input
GND
- Ground
N.C.
- No Connection
X1, X2
- Crystal Connection
VBAT
- Battery Connection
ORDERING INFORMATION
PART
TEMP RANGE
VOLTAGE
(V)
PIN-PACKAGE
TOP MARK**
DS1556-70+
0°C to +70°C
5.0
32 EDIP (0.740a)
DS1556+070
DS1556-70IND+
-40°C to +85°C
5.0
32 EDIP (0.740a)
DS1556+070 IND
DS1556P-70+
0°C to +70°C
5.0
34 PowerCap*
DS1556P+70
DS1556P-70IND+
-40°C to +85°C
5.0
34 PowerCap*
DS1556P+70 IND
DS1556W-120+
0°C to +70°C
3.3
32 EDIP (0.740a)
DS1556W+120
DS1556W-120IND+
-40°C to +85°C
3.3
32 EDIP (0.740a)
DS1556W+120 IND
DS1556WP-120+
0°C to +70°C
3.3
34 PowerCap*
DS1556WP+120
DS1556WP-120IND+
-40°C to +85°C
3.3
34 PowerCap*
DS1556WP+120 IND
+Denotes a lead(Pb)-free/RoHS-compliant package.
*DS9034-PCX+ or DS9034I-PCX+ required (must be ordered separately).
**A “+” in top mark denotes a lead(Pb)-free device. An “IND” anywhere on the top mark indicates an industrial temperature grade device.