Patent ID: 6256215
Filing Date: 2001-07-03
Classification: H02M,H03K

Abstract:
A multiple power supply transistor bridge circuit comprising:first and second series connected power supplies defining a ground potential, and first and second power supply voltages relative to said ground potential;first and second bridge transistors coupled to said first power supply voltage, a third bridge transistor connected in series with said second bridge transistor to form a bridge circuit for said second power supply, and a fourth bridge transistor connected in series with said first bridge transistor to form a bridge circuit for said first power supply, each of said bridge transistors having a gate drive amplifier for biasing the respective bridge transistor on and off in accordance with a control signal applied thereto;a logic level power supply coupled between said first power supply voltage and ground potential for establishing a logic level voltage relative to said ground voltage;a first by-pass capacitor coupled to said logic level voltage and to a junction between said first and fourth bridge transistors for receiving charging current from said logic level power supply when said fourth bridge transistor is biased on, thereby to establish a first gate drive voltage for the gate drive amplifier of said first bridge transistor; anda second by-pass capacitor coupled to said first power supply voltage and to said first by-pass capacitor for receiving charging current from said first by-pass capacitor when said first bridge transistor is biased on, thereby to establish a second gate drive voltage for the gate drive amplifier of said second bridge transistor.