Abstract: A circuit adapting pin output levels to a reference level in which a digital comparator compares an output voltage from an output pin of a device to a reference voltage level. The comparator, relying on the polarity of the comparator output as well as the registered polarity of the comparator output on the previous clock cycle, signals a state machine, which sends a clocked signal to a sense circuit and voltage regulator. The sense circuit may modify a resistance in a switched resistor network, such that the output level is incrementally stepped at clocked intervals towards the reference voltage until the polarity of the error signal reverses. When the output voltage crosses the reference voltage threshold, the comparator flips states and continues to regulate output pin voltage to the reference voltage level.

Abstract: A circuit adapting pin output levels to a reference level in which a digital comparator compares an output voltage from an output pin of a device to a reference voltage level. The comparator, relying on the polarity of the comparator output as well as the registered polarity of the comparator output on the previous clock cycle, signals a state machine, which sends a clocked signal to a sense circuit and voltage regulator. The sense circuit may modify a resistance in a switched resistor network, such that the output level is incrementally stepped at clocked intervals towards the reference voltage until the polarity of the error signal reverses. When the output voltage crosses the reference voltage threshold, the comparator flips states and continues to regulate output pin voltage to the reference voltage level.