Patent ID: 8823419
Filing Date: 2014-09-02
Classification: H03K

Abstract:
1. A ping pong comparator voltage monitoring circuit, comprising: a first comparator having a first input connected to a voltage Vin to be monitored, a second input connected to a first node, and an output which toggles from a first state to a second state when Vin increases above the voltage applied to said first comparator's second input and toggles from said second state to said first state when Vin falls below the voltage applied to said first comparator's second input; a second comparator having a first input connected to said voltage Vin, a second input connected to a second node, and an output which toggles from a first state to a second state when Vin increases above the voltage applied to said second comparator's second input and toggles from said second state to said first state when Vin falls below the voltage applied to said second comparator's second input; a multiplexer connected to receive the outputs of said first and second comparators at first and second inputs, respectively, and to receive a periodic control signal at a ‘select’ input, said multiplexer arranged to alternately couple the voltage applied to said first and second inputs to an output in response to said periodic control signal, said multiplexer output being the output of said voltage monitoring circuit; a first reference voltage source which produces a voltage V a second reference voltage source which produces a voltage V a first hysteresis voltage source which produces a voltage hyst a second hysteresis voltage source which produces a voltage hyst said voltage monitoring circuit arranged such that said first and second hysteresis voltage sources are switched in such that the voltage at said first node is V and such that the voltage at said first node is V