7-39

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

407-727-9207

CA3277

Dual 5V Regulator with Serial Data Buffer

Interface for Microcontroller Applications

Description

The CA3277 is a Dual 5V Voltage Regulator IC intended for micro-

processor and logic controller applications. It is supplied with fea-

tures that are commonly specified for sequentially controlled

shutdown and startup requirements of microcontrollers. Over-volt-

age shutdown, short circuit current limiting and thermal shutdown

features are provided for protection in the harsh environmental appli-

cations of industrial and automotive systems. The CA3277 functions

are complementary to the needs of microcontroller and memory cir-

cuits, providing for sustained memory with a 5V standby output.

The Ignition Comparator senses the voltage level at the IGN IN input

and provides a 5V logic switched output (supply sourced

from

OUT1). The Ignition Output, IGN OUT can be used to signal a sys-

tem microcontroller which can respond with a logic switched output

to the CA3277 ENABLE input control for OUT2. The OUT1 +5V

Standby Supply of the regulator is normally used as a power supply

for microcontroller/memory circuits to preserve stored data when in

the standby mode.To allow for maximum heat transfer from the chip,

the four center leads are directly connected to the die mounting pad.

Refer to AN9302 for further information on CA3277 circuit Applica-

tions.

Ordering Information

PART NUMBER

TEMPERATURE RANGE

PACKAGE

CA3277E

16 Lead Plastic DIP

Features

• Dual 5V Regulator

- Regulation Range 6V to 18V

- Bandgap Voltage References

• Low Quiescent Idle Current, 500

µA Typ.

• Over-Voltage Shutdown Protection, 20.5V Typ.

• Reverse Battery Protection, -26V Max.

• Thermal Shutdown Protection

• Short Circuit Current Limiting

• Low Input P.S. Flag and Delayed Reset Control

• Low Voltage Shutdown Control, Ouput1

• Ignition Comparator Logic Level Control

• Data Comparator and 100X Current Mult. Used

as Input/Output Buffers for Remote Serial Data

Communication

Applications

• Automotive 5V Regulators and Data Buffers

• Industrial Controller Remote System

• Microcontroller and Memory Power Supply

• Radio, TV, CATV, Consumer Applications

File Number

2792.4

April 1994

Pinout

CA3277 (PDIP)

TOP VIEW

14

15

16

9

13

12

11

10

1

2

3

4

5

7

6

8

IGN

ENABLE

GND

GND

IGN OUT

CUR IN

CUR OUT

OUT2

BATT

OUT1

DATA IN

GND

GND

DATA OUT

RESET

CRST

Functional Block Diagram

4, 5 AND

12, 13

OUT1 REG.

DR. CNTRL

BANDGAP

VOLTAGE

REF

2

RESET

CRST

8

7

BATT

1

OVER-

SHTDWN

15

OVER-

SHTDWN

ENABLE 14

CURRENT

MULTIPLIER

IGN

11

OUT

10

CUR

OUT

9

16

IGN IN

3

DATA IN

6

DATA

OUT

GND

-

+

(OUTPUT2)

TEMP

OUT2 REG.

DR. CNTRL

OUT1

OUT2

LOW

VOLTAGE

SHTDWN

VOLTAGE

6V

1.2V

+5V

(STANDBY)

+5V

(ENABLE)

CUR

IN

-

+

IN

-

+

-

+

-

+

-

+