Current Sources and Voltage References

Creating precision current regulators with op amps

Creating Precision Current Sources with Op Amps and Voltage References

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An alternative to this circuit is shown in Figure 11.12, which is a fast, differential-

input, bilateral current pump. It looks similar to the previous example but uses a sec-

ond op amp in place of the trimmer. It produces an output current of up to ±10 mA,

proportional to the differential input voltage, which in this example is limited to ±1 volt.

A higher output current is achievable if one uses an op amp with a higher-rated out-

put current. In this circuit the second op amp A

2

is used as a buffer in the feedback

loop of ...