| 摘要 |
Circuitry for reducing charge injection effects in an offset voltage compensation circuit for a switched-capacitor amplifier is provided. The switched-capacitor amplifier circuitry includes an operational amplifier having inverting and noninverting inputs and an output. An initialization circuit provides the inverting input with a voltage close to the offset voltage of the operational amplifier. A feedback circuit ensures that the voltage at the inverting input attains the offset voltage. In order to attenuate the effects of disengaging the feedback circuit after the input voltage attains the offset voltage, an attenuation circuit is provided. The attenuation circuit prevents the voltage at the inverting input from being affected by charge injection effects that arise when the feedback circuit is disengaged. The offset voltage compensation circuit may be used with switched-capacitor amplifiers configured as comparators, amplifiers, or successive approximation A/D converters.
|
