Patent ID: 7714620
Filing Date: 2010-05-11
Classification: H03K

Abstract:
1. A system comprising: a reference voltage generator configured to generate a first reference voltage based on an input reference voltage and a second reference voltage based on the input reference voltage, the first reference voltage being higher than the second reference voltage, the reference voltage generator further configured to select the first reference voltage and the second reference voltage based on a first control input, wherein the first reference voltage and the second reference voltage define an amplitude hysteresis, the amplitude hysteresis being a voltage difference between the first reference voltage and the second reference voltage; a first comparator circuit coupled to the reference voltage generator and configured to receive an input signal, the first comparator circuit further configured to generate a first signal indicating whether the input signal is higher than the first reference voltage; a second comparator circuit coupled to the reference voltage generator and configured to receive the input signal, the second comparator circuit further configured to generate a second signal indicating whether the input signal is lower than the second reference voltage; and a latch coupled to the first comparator circuit and the second comparator circuit, the latch configured to be set to a first state if the first signal indicates the input signal is higher than the first reference voltage and to be set to a second state if the second signal indicates the input signal is lower than the second reference voltage.