LTC2945

27

Rev. C

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Power Monitoring in –48V System Using Low Side Sensing (1.5kHz I2C Interface)

TYPICAL APPLICATIONS

C1

1µF

CONTROL REGISTER A2 = 0

MOCD207M

MOCD207M

2945 TA05

ADR0

ADR1

SCL

VDD INTVCC

VEE

SDAI

SDAO

ADIN

ALERT

SENSE–

GND

SENSE+

LTC2945

C2

0.1µF

–48V

RTN

VEE

–48V INPUT

R7

0.51k

R3

1k

R4

1k

VOUT

R8

0.51k

R9

10k

R10

10k

R11

10k

3.3V

RSNS

0.02

VDD

GND

µP

SCL

SDA

INT

R1

20k

R2

20k

VCC

GND

RSHUNT

3

× 1.8k IN SERIES

C1

1µF

HCPL-063L

CONTROL REGISTER A0 = 0

VEE

VEE

HCPL-063L

2945 TA06

ADR0

ADR1

SCL

VDD

INTVCC

SDAI

SDAO

ADIN

ALERT

SENSE–

GND

SENSE+

LTC2945

VCC

GND

–48V

RTN

VEE

–48V INPUT

R7

0.51k

R3

0.51k

R4

1k

VOUT

C2

1µF

R8

0.51k

R9

1k

R10

1k

R11

10k

3.3V

3.3V

RSNS

0.02

VDD

GND

µP

SCL

SDA

INT

R12

100

Q1

PZTA42

D1

1N4148WS

R1

1k

R2

1k

R5

735k

R6

15k

Power Monitoring in –48V Harsh Environment Using INTVCC Shunt Regulator to Tolerate 200V Transients