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DS1221 Nonvolatile Controller X 4 Chip Datasheet
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Features
Control Circuitry to Make CMOS RAM Nonvolatile
Controls up to 4 Memories
Monitors Vcc and Write protects when out of Tolerance
Consumes less than 100nA Battery Current
Tests Battery Condition on Start-Up
Supports redundant batteries
Pin Layout
Pin Description
| Pin Number | Description |
|---|---|
| 1 | Vcco - RAM Supply |
| 2 | Vbat1 - +Battery 1 |
| 3 | RST - Reset |
| 4 | A - Address Input A |
| 5 | B - Address Input B |
| 6 | RD - Read Input |
| 7 | WE - Write Enable |
| 8 | GND - Ground |
| 9 | D/Q - Data Input/Output |
| 10 | CE3 - Chip Enable Output 3 |
| 11 | CE2 - Chip Enable Output 2 |
| 12 | CE1 - Chip Enable Output 1 |
| 13 | CE0 - Chip Enable Output 0 |
| 14 | CE - Chip Enable Input |
| 15 | Vbat2 - +Battery 2 |
| 16 | Vcci - +5V Supply |
Dimensional Drawing
Technical Data
Datasheet
Application Notes