AN4439 datasheet(5/16 Pages) STMICROELECTRONICS

부품명	AN4439

상세설명	L99ASC03 current sense amplifier offset adjust

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AN4439

The L99ASC03 current sense amplifier circuit

The L99ASC03 current sense amplifier consists of two stages. The first stage is a fixed gain

of 10 inverting amplifier. The second stage is a programmable gain inverting amplifier. The

second stage programmable voltage gain (AV2) can be programmed for a gain of 2, 3, 7, or

10. This translates to system gain settings of 20, 30, 70 and 100 when considering both op-

amps.

Figure 1. L99ASC03 current sense amplifier circuit

Where:

•

R1=R2=10 kΩ +45 % / -15 % (semiconductor resistor vary a lot and they vary together.

As a result ratios stay fairly tight)

•

VX = 2.5 V +/-2 %

With both the CSI+ and CSI- pins available we can add a few resistors to the CSI- pin to

generate an appropriate offset to bring the CSO @ 0 A to close to 0 V.

Figure 2. L99ASC03 input offset circuit

GAPG2002140828MS

AN4439 데이터시트(PDF) 5 Page - STMicroelectronics