Patent ID: 7898315
Filing Date: 2011-03-01
Classification: G01R,H03K,H03M

Abstract:
1. An analog multiplexer with an insulated power supply, comprising: an analog signal transformer, which receives an input of an analog signal in a primary winding of the analog signal transformer via a first semiconductor switch, and performs ON/OFF driving on the first semiconductor switch, to thereby generate a pulse with an amplitude of the analog signal in a secondary winding of the analog signal transformer; a drive transformer, which receives an input of a drive pulse in a primary winding of the drive transformer via a second semiconductor switch, to thereby generate a pulse for turning ON/OFF the first semiconductor switch in a secondary winding of the drive transformer; an inhibit generation circuit, which generates an inhibit pulse having a pulse width wider than a pulse width of the drive pulse; a continuous pulse generation circuit, which generates a continuous pulse having a pulse width narrower than the pulse width of the drive pulse; an AND gate, which determines a logical product of the inhibit pulse sent from the inhibit generation circuit and the continuous pulse sent from the continuous pulse generation circuit, to thereby obtain a power supply pulse train for driving a primary winding of a power supply transformer; and a rectifying/smoothing circuit connected to a secondary winding of the power supply transformer, which obtains a direct current voltage corresponding to the power supply pulse train, to thereby apply the direct current voltage to the primary winding of the analog signal transformer through high resistance.