Current Sources and Voltage References

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A look to the future

very-low-offset, low-drift precision type. The buffers connect to the output of the filter

and directly drive the input of each A/D converter’s internal reference ladder (each of

which has a small capacitor across it). The capacitors used in the filter should be high-

quality polypropylene types, and the resistors should be precision low TC types. Either

circuit could use a reference with noise-reduction terminals if desired, which could

simplify the design (but may not provide as good a level of filtering). However, before

doing anything, you should first be aware of the noise characteristics involved, starting

with the noise requirements ...