DS1200
Serial RAM Chip
www.maxim-ic.com
FEATURES
PIN ASSIGNMENT
C 1024 Bits of Read/Write Memory
C Low Data Retention Current for Battery
Backup Applications
C Four Million Bits/Second Data Rate
C Single-Byte or Multiple-Byte Data Transfer
Capability
C No Restrictions on the Number of Write
Cycles
16-Pin SO (300mil)
C Low-Power CMOS Circuitry
See Mech. Drawings Section
APPLICATIONS
C Software Authorization
C Computer Identification
C System Access Control
C Secure Personnel Areas
C Calibration
PIN DESCRIPTION
VCC
- +5V
RST
- Reset
C Automatic System Setup
C Traveling Work Record
DQ
- Data Input/Output
- Clock
CLK
GND
VBAT
NC
- Ground
- Battery (+)
- No Connection
DESCRIPTION
The DS1200 serial RAM chip is a miniature read/write memory that can randomly access individual
8-bit strings (bytes) or sequentially access the entire 1024-bit contents (burst). Interface cost to a
microprocessor is minimized by on-chip circuitry, which permits data transfers with only three signals:
CLK, RST , and DQ.
Nonvolatility can be achieved by connecting a battery of 2V to 4V at the battery input VBAT. A load of
0.5ꢀꢁꢂshould be used to size the external battery for the required data retention time. If nonvolatility is
not required the VBAT pin should be grounded.
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