Patent ID: 8446307

Claim:
A comparator, including: a preamplifier amplifying a first signal and a second signal to produce a first amplified signal on a first output terminal and a second amplified signal on a second output terminal; a variable capacitor, a clamp and a latch coupled in parallel to the first output terminal and the second output terminal of the preamplifier; and a control circuit coupled to the variable capacitor and the clamp, the control circuit configured to: close the clamp during a first time period to cause the first amplified signal and the second amplified signal to bypass the capacitor and the latch, and open the clamp during a second time period following the first time period to cause the first amplified signal and the second amplified signal to be coupled to the capacitor and the latch, the capacitor filtering the amplified signals, and the latch producing a digital output signal of the comparator based on the filtered signals.