DRIVER FOR INDUCTIVE LOAD

摘要

A driver for an inductive load such as a solenoid coil 92 includes three FETs 4,6,8. Two of the FETs are reversely connected between battery and output terminals 16, 18, and one of the FETs is connected between output and ground terminals 16, 14. A driver circuit 10 having high and low side control circuitry 58,56 is formed in a common substrate with two of the FETs 4,6. In use, a coil 92 is connected to the output terminal 16, and driven in an energise mode in which current in the coil 92 is built up as indicated by arrow 100, a freewheel mode in which current circulates freely as indicated by arrow 102, and then may be switched off. The reversely connected FETs allow both short circuits to be prevented in the energise mode and allow the coil to be rapidly switched off. In spite of the control circuitry being formed in a common substrate with some of the FETs, the arrangement allows the FETs to be properly driven.