Patent ID: 7102396
Filing Date: 2006-09-05
Classification: H04M,H04W,Y02D

Abstract:
1. A hysteresis detecting circuit comprising: a comparator for comparing an input signal and a reference potential; a switch for selecting said reference potential from a plurality of voltage sources having stabilization times; and a delay circuit for supplying a low level signal as said input signal for a period of time corresponding to said stabilization times of said plurality of voltage sources, wherein said switch selects one of said plurality of voltages sources as said reference potential during an initial state of said hysteresis detecting circuit, wherein said delay circuit comprises: a constant current source; a capacitor connected in series to said constant current source; an inverter connected to a connection point between said constant current source and said capacitor; and a transistor connected to the output of said inverter, wherein the drain of said transistor is connected to said input signal.