TSZ182

V1

V2

Rg

Rf

Rf

R2

R4

R1

R3

TSZ181

Vout

TSZ182

+

-

-

+

-

+

The gain is set by tuning the Rg resistor. To have the best performance, it is suggested to have R1 = R2 = R3 =

R4. The output is given by Equation 2.

Equation 2

The matching of R1, R2 and R3, R4 is important to ensure a good common mode rejection ratio (CMR).

5.14.3

Low-side current sensing

Power management mechanisms are found in most electronic systems. Current sensing is useful for protecting

applications. The low-side current sensing method consists of placing a sense resistor between the load and the

circuit ground. The resulting voltage drop is amplified using the TSZ181 (see Figure 64. Low-side current sensing

schematic).

-

+

+

-

Rshunt

Rg1

Rg2

C1

Rf1

5 V

Vout

Rf2

T SZ181

I

In

Ip

Equation 3

+

1

–

×

1

+

–

–

+

=

+

+

×

×

+

×

Equation 4

×

–

×

+

=

+

TSZ181, TSZ182

Application examples

DS11863 - Rev 5

page 26/43