Current Sources and Voltage References

Using the enhancement-mode MOSFET as a current source

Creating Current Sources with Power MOSFETs

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We will use Figure 8.18 as a design example, because the combination of a monolithic

voltage reference together with a power MOSFET would be useful in many applica-

tions. In this example of a power current sink, one should first determine the voltage

supplies and the current output required. Let’s suppose that we have 12 volts (±5%)

available and that the current required through the power FET is 4 Amps. The power

MOSFET required needs to have a V

(BR)DSS

of at least 18 volts and a current rating

(at 100˚C) of at least 6 Amps. We should check the FET’ ...