6

Typical applications

6.1

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 TSB952 (see the figure below).

Figure 51. Low-side current sensing schematic

VOUT can be expressed as follows:

VOUT=Rsℎunt⋅I1− Rg2Rg2+Rf2 ⋅ 1+Rf1Rg1 +Ip⋅Rg2⋅Rf2

Rg2+Rf2⋅ 1+Rf1Rg1 −In⋅Rf1

− 1+Rf1Rg1

(4)

Assuming that Rf2 = Rf1 = Rf and Rg2 = Rg1 = Rg, Eq. (4) can be simplified as follows:

VOUT=Rsℎunt⋅I⋅RfRg−VIO⋅ 1+RfRg +Rf⋅IIO

(5)

The main advantage of using the TSB952 for low-side current sensing relies on its speed (high bandwidth and

slew rate) allowing for a better control of many applications thanks to its fast detection of current change.

TSB952

Typical applications

DS14576 - Rev 1

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