Patent ID: 6960938

Claim:
An enhanced CMOS circuit to drive a DC motor used in a portable CD player, comprising: a first and a second switching stage ( 10 ) ( 10 ′), wherein each switching stage is formed by a pair of PMOS transistors ( 11 ) ( 12 ) connected in series and a pair of NMOS transistors ( 13 ) ( 14 ) connected in series to form a push-pull circuit; wherein one end of each switching stage is connected to a positive power supply terminal with higher voltage, and another end is connected either to ground or negative power supply terminal; wherein a node connecting the pair of PMOS connectors ( 11 ) ( 12 ) and the pair of NMOS transistors ( 13 ) ( 14 ) acts as an output of the switching stages ( 10 ) ( 10 ′); wherein a gate electrode of one of the two PMOS transistors ( 11 ) and one of the two NMOS transistors ( 14 ) are tied together to share a common input signal; a gate of the other PMOS transistor ( 12 ) is connected to a first power source with a predetermined control voltage, and a gate of the other NMOS transistor ( 13 ) is connected to a second power source with a predetermined control voltage, to form a voltage divider, whereby individual transistors tolerate an operating voltage; and a driver stage ( 20 ) formed by two NMOS transistors ( 21 ) ( 22 ) connected in series; wherein a node connecting the two NMOS transistors ( 21 ) ( 22 ) is used as an output for connection to a DC motor (M); one of the two NMOS transistors ( 21 ) is to receive gating signals from the first switching stage ( 10 ); the other NMOS transistor ( 22 ) is to receive complementary signals from the second switching stage ( 10 ′).