PURPOSE: To obtain an amplifier gate drive control circuit which can prevent a gate drive signal from staying on when a transmission pulse width data is changed and a pulse width is updated and noise from being included in a receiver part.

CONSTITUTION: A pulse width modification signal is passed through an one-shot circuit 16. AND operation is performed between a pulse period signal which is output from a latch and one part of a pulse width signal, and then a gate drive signal is reset once, thus enabling the gate drive signal to be output. When the pulse width is changed according to change in the pulse width, data can be output at a normal timing after the gate drive signal is reset once and the pulse width is changed, thus preventing noise from being included in a receiver part etc.