Patent ID: 7106107

Claim:
A comparator circuit, comprising: a reference generator connecting to a first source providing a first voltage, the reference generator being operative to generate a reference signal and including a control circuit selectively operable in one of at least a first mode and a second mode in response to a first control signal applied to the reference generator, wherein in the first mode the reference signal is not generated, and in the second mode the reference generator is operative to generate the reference signal; a comparator connecting to a second source providing a second voltage, the second voltage being less than the first voltage, the comparator being operative to receive the reference signal and an input signal, and to generate an output signal which is a function of a comparison between the input signal and the reference signal; a hysteresis circuit operative to selectively control a switching threshold of the comparator, relative to the input signal, as a function of the output signal of the comparator; and a voltage clamp operative to limit a voltage applied to at least one of the control circuit, the comparator, and the hysteresis circuit to less than the second voltage.