SGM321/358/324

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Typical Application Circuits

Differential Amplifier

The circuit shown in Figure 4 performs the difference function. If

the resistors ratios are equal ( R4 / R3 = R2 / R1 ), then

Vn

Vp

SGM321

Vref

R1

R2

R3

R4

Figure 4. Differential Amplifier

Instrumentation Amplifier

The circuit in Figure 5 performs the same function as that in Figure 4

but with the high input impedance.

Vn

Vp

SGM321

Vref

R1

R2

R3

R4

SGM321

SGM321

Figure 5. Instrumentation Amplifier

Low Pass Active Filter

and the –3dB corner frequency is 1/2

within the bandwidth of the amplifier. The Large values of feedback

resistors can couple with parasitic capacitance and cause undesired

effects such as ringing or oscillation in high-speed amplifiers. Keep

resistors value as low as possible and consistent with output loading

consideration.

SGM321

R1

R2

R3 = R1 // R2

C

Figure 6. Low Pass Active Filter