LTC2945

27

2945f

TYPICAL APPLICATIONS

Power Monitoring in –48V System Using External Linear Regulator to Supply Opto-couplers and SCL/SDA Resistive Pull-Ups

Wide Range Dual Supply Monitor with Single LTC2945

GND

C1

1μF

PS9817-2

CONTROL REGISTER A2 = 0

PS9817-2

2945 TA07

ADR0

ADIN

ADR1

SCL

SDAI

SDAO

ALERT

GND

LTC2945

LT3010-5

GND

–48V

RTN

–48V INPUT

R7

0.5k

R3

0.51k

R4

1k

R8

0.51k

R9

1k

R10

1k

R11

10k

5V

5V

0.02Ω

GND

μP

SCL

SDA

INT

R1

1k

R2

10k

IN

SHDN

OUT

SENSE

GND

C3

0.1μF

C2

1μF

* SELECT RSHUNT ACCORDING TO THE EQUATION IN THE “FLEXIBLE POWER SUPPLY TO LTC2945” SECTION.

** VOLTAGE DATA HAS AN OFFSET VALUE DUE TO D1’S DROP, IF DESIRABLE THIS CAN BE COMPENSATED THROUGH SOFTWARE.

20k

2945 TA08

0.02Ω

C3

0.1μF

C2

0.1μF

ADR0

ADR1

SDAI

SCL

SDAO

ALERT

ADIN

GND

LTC2945

LTC6102

1k

D2

BAT54

D1

BAT54

1k

C1

0.1μF

0.02Ω

–INF –INS

OUT

+IN

SUPPLY B

4.5V TO 80V

SUPPLY A

4.5V TO 80V

INTERFACE

TO

LOAD

SUPPLY A

ΔSENSE INTERNALLY GENERATED

AND CURRENT (ADIN) DATA

ADIN

1

VOLTAGE

DATA

CURRENT

DATA

POWER

DATA

CONTROL REG

A2

0

SUPPLY B