摘要 |
An integrator circuit having a relatively large RC time constant includes a resistive element implemented with a field effect transistor operated in a sub-threshold mode. The size of the field effect transistor is selected, in addition to the sub-threshold gate voltage, to achieve a desired resistance value in a small area and without using bipolar devices. A differential integrator circuit includes two field effect transistors operated in a sub-threshold mode, with a capacitor connected between the output terminals of the two field effect transistors. A bulk drive circuit can be optionally used to reduce high frequency in the bulk.
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