Linear Technology LT2940 Power & Current Monitor DC1495A DC1495A 数据表

LT2940

1

2940f

Power and Current Monitor

The LT

®

2940 measures a high side current and a differ-

ential voltage, multiplies them and outputs a current 
proportional to instantaneous power. Bidirectional high 
side currents and bipolar voltage differences are correctly 
handled by the four-quadrant multiplier and push-pull 
output stage, which allows the LT2940 to indicate forward 
and reverse power fl ow.

An integrated comparator with inverting and noninvert-
ing open-collector outputs makes the LT2940 a complete 
power level monitor. In addition, an output current pro-
portional to the sensed high side current allows current 
monitoring. The current mode outputs make scaling, 
fi ltering and time integration as simple as selecting ex-
ternal resistors and/or capacitors.

n

  Four-Quadrant Power Measurement

n

  ±5% Power Measurement Accuracy

n

  4V to 80V High Side Sense, 100V Max

n

  Current Mode Power and Current Outputs

n

  Output Bandwidth Exceeds 500kHz

n

  ±3% Current Measurement Accuracy

n

  6V to 80V Supply Range, 100V Max 

n

  Inverting and Noninverting Open-Collector 

Comparator Outputs

n

  Available in 12-Pin DFN (3mm 

× 3mm) and 12-Lead 

MSOP Packages

n

  Board Level Power and Current Monitoring

n

  Line Card and Server Power Monitoring

n

  Power Sense Circuit Breaker

n

  Power Control Loops

n

 Power/Energy Meters

n

  Battery Charger Metering

CMP

+

PMON

IMON

CMPOUT

CMPOUT

LATCH

V

–

V

+

I

–

I

+

2940 TA01a

V

CC

110k

+

–

10.0k

0A TO 10A

LED ON WHEN

P

LOAD

 > 60W

P

LOAD

 = V

LOAD

• I

LOAD

V

LOAD

6V TO 80V

I

LOAD

LT2940

GND

20mΩ

2W

5V

1k

V

IMON

 = I

LOAD

• 100

mV

A

V

PMON

 = P

LOAD

• 20.75

mV

W

24.9K

4.99k

LOAD

k

V

 = 

k

I

 = 20mΩ

1

12

I

LOAD

 (A)

P

LOAD

 (W)

0

V

PMON

 (V)

2.0

1.5

1.0

4

8

2

6

10

12

14

0.5

0

2.5

96

72

48

24

0

120

80V

30V

15V

10V

2940 TA01b

LED ON

LED OFF

V

LOAD

= 6V

60W ALARM

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear 
Technology Corporation. All other trademarks are the property of their respective owners.