1

LTC1392

Micropower Temperature,

Power Supply and

Differential Voltage Monitor

1

2

3

4

8

7

6

5

GND

CLK

CS

LTC1392

LTC1392 • TA01

5V

+

1

µF

MPU

(e.g., 68HC11)

P1.4

P1.3

P1.2

TEMPERATURE (

°C)

–40

5

4

3

2

1

0

–1

–2

–3

–4

–5

0

40

60

LTC1392 • TA02

–20

20

80

100

LTC1392C

GUARANTEED

LIMIT

LTC1392I

GUARANTEED

LIMIT

TYPICAL

DESCRIPTIO

S

FEATURE

s

Complete Ambient Temperature Sensor Onboard

s

System Power Supply Monitor

s

10-Bit Resolution Rail-to-Rail Common-Mode

Differential Voltage Input

s

Available in 8-Pin SO and PDIP

s

0.2

µA Supply Current When Idle

s

700

µA Supply Current When Sampling at

Maximum Rate

s

Single Supply Voltage: 4.5V to 6V

s

3-Wire Half-Duplex Serial I/O

s

Communicates with Most MPU Serial Ports and All

MPU Parallel I/O Ports

The LTC

designed to measure temperature, on-chip supply voltage

and a differential voltage. The differential inputs feature

rail-to-rail common mode input voltage range. The LTC1392

contains a temperature sensor, a 10-bit A/D converter with

sample-and-hold, a high accuracy bandgap reference and

a 3-wire half-duplex serial interface.

The LTC1392 can be programmed to measure ambient

temperature, power supply voltage and an external volt-

age at the differential input pins, that can also be used for

current measurement using an external sense resistor.

When measuring temperature, the output code of the A/D

converter is linearly proportional to the temperature in

°C.

Production trimming achieves

±2°C initial accuracy at

room temperature and

±4°C over the full –40°C to 85°C

temperature range.

The on-chip serial port allows efficient data transfer to a

wide range of MPUs over three or four wires. This,

coupled with low power consumption, makes remote

location sensing possible and facilitates transmitting

data through isolation barriers.

S

APPLICATI

s

Temperature Measurement

s

Power Supply Measurement

s

Current Measurement

s

Remote Data Acquisition

s

Environment Monitoring

, LTC and LT are registered trademarks of Linear Technology Corporation.

APPLICATI

TYPICAL

Complete Temperature, Supply Voltage and

Supply Current Monitor

Output Temperature Error