| 摘要 |
PROBLEM TO BE SOLVED: To reduce amplitude of a sensing signal for detection of excess current while maintaining detection accuracy. SOLUTION: A power amplifier for driving a load L connected to an output terminal OUT is disclosed, wherein an output transistor and a corresponding current detection path are connected in parallel between the output terminal and a power source. The detection path is provided with a switch element and a resistor connected in series, turns a corresponding switch element on only in an on period of a corresponding output transistor and detects presence/absence of generation of the excess current in the respective output transistors based on the sensing signal obtained from a connection point between the switch element and the resistor. When the excess current is detected, an operation of the output transistor is stopped to protect an amplifier. COPYRIGHT: (C)2009,JPO&INPIT
|
