Current Sources and Voltage References

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Enhancing the voltage reference design

forcing feedback loop of the op amp. The loop forces the output to compensate for all

of these errors, and thus provides the exact same voltage to the load as exists on-

chip. While that is its primary purpose, it also works in a similar manner when includ-

ing any filtering and/or buffering (such as in providing a reference voltage with a much

higher current output, e.g., 50 mA, 150 mA, 600 mA). As an example, Figure 12.15A

shows the general feedback arrangement using a simple buffer, which is shown within

the dotted box. This may be replaced by a power op amp buffer with even higher cur-

rent output capability ...