TSX920 datasheet(21/32 Pages) STMICROELECTRONICS

Nome de Peças	TSX920

Descrição Electrónicos	10 MHz rail-to-rail CMOS 16 V operational amplifiers

PDF	32 Pages

Scroll/Zoom	100%

Fabricante Electrônico	STMICROELECTRONICS [STMicroelectronics]

Página de início	http://www.st.com

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21 / 32 page

TSX920, TSX921, TSX922, TSX923

Application information

DocID024310 Rev 4

21/32

5.7

High-side current sensing

TSX92x rail to rail input devices can be used to measure a small differential voltage on a

high side shunt resistor and translate it into a ground referenced output voltage. The gain is

fixed by external resistance.

Figure 41: High-side current sensing configuration

Vout can be expressed as follows:

Equation 8

Assuming that Rf2 = Rf1 = Rf and Rg2 = Rg1 = Rg, Equation 8 can be simplified as follows:

Equation 9

With the TSX92x operational amplifiers, the high side current measurement must be made

by respecting the common mode voltage of the amplifier: (VCC-) - 0.1 V to (VCC+) + 0.1 V. If

the application requires a higher common voltage please refer to the TSC high side current

sensing family.

ou t

shun t

I 1

–

io 1

–

out

shunt

io 1

–

TSX920 Folha de dados(PDF) 21 Page - STMicroelectronics