1 of 1

111899

VCCI

VBAT2

VBAT1

VCCO

TOL

PF

CE7

CE6

C

B

A

GND

CE

CE0

CE1

CE2

CE3

NC

CE4

CE5

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

VBAT1

VCCO

TOL

PF

CE7

CE6

C

B

A

GND

VCCI

VBAT2

CE

CE0

CE1

CE2

CE3

NC

CE4

CE5

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

20-Pin DIP (300-mil)

See Mech. Drawings

Section

20-Pin SOIC (300-mil)

See Mech. Drawings

Section

FEATURES

Converts full CMOS RAMs into nonvolatile

memories

out of tolerance

Automatically switches to battery when

power-fail occurs

3 to 8 decoder provides control for up to eight

CMOS RAMs

Consumes less than 100 nA of battery current

Tests battery condition on power-up

Provides for redundant batteries

Power-fail signal can be used to interrupt

processor on power failure

Optional 5% or 10% power-fail detection

Optional 20-pin SOIC surface mount package

Optional industrial temperature range of

-40°C to +85°C

PIN ASSIGNMENT

PIN DESCRIPTION

A, B, C

- Address Inputs

CE

- Chip Enable Input

CE0

- Chip Enable Outputs

GND

- Ground

- + Battery 1

- + Battery 2

TOL

- Power Supply Tolerance

- +5V Supply

- RAM Supply

PF

- Power-fail

NC

- No Connection

DESCRIPTION

The DS1211 Nonvolatile Controller x 8 Chip is a CMOS circuit which solves the application problem of

converting CMOS RAMs into nonvolatile memories. Incoming power is monitored for an out-of-

tolerance condition. When such a condition is detected, the chip enables are inhibited to accomplish write

protection and the battery is switched on to supply RAMs with uninterrupted power. Special circuitry

uses a low-leakage CMOS process which affords precise voltage detection at extremely low battery

consumption.

By combining the DS1211 nonvolatile controller/decoder chip and lithium batteries, nonvolatile RAM

operation can be achieved for up to eight CMOS memories.

See the data sheet for the DS1212 Nonvolatile Controller x 16 Chip for electrical specifications and

operation.

DS1211

Nonvolatile Controller x 8 Chip

www.dalsemi.com