MS1100

Hangzhou Ruimeng Technology Co.,Ltd

VERSION : V1.10

2023.05.22

http://www.relmon.com

- PAGE 12 -

Low-Side Current Monitor

Figure 6 shows a circuit for a low-side current monitor. The circuit reads the voltage across a shunt resistor,

the voltage of which is amplified by the MS8552, and the result is read by the MS1100.

It is suggested that the MS1100 be operated at a gain of 8. The gain of the MS8552 can be reduced. For a

gain of 8, the op amp should provide output voltage of no greater than 0.256V. Therefore, the shunt resistor

is sized to provide a maximum voltage drop of 64mV at full-scale current.

MS1100

LOAD

MS8552

RS

(2)

1kΩ

3kΩ

G=+4

49.9kΩ

R3

(1)

FS = 0.256V

(P GA Gain = 8)

FS = 0.2V

0.1μF

VDD

VREF

5V

I

2C

NOTE: (1) Pull-down resistor allows outpu t to 0V.

(2) RS is sized for a 64mV drop at full-scale current.

Figure 6. Low-Side Current Measurement