| 摘要 |
A current detection circuit applicable to a switching circuit using switching transistors to supply a prescribed load current to a load, comprises a sample-hold capacitor for temporarily holding a terminal voltage of the switching transistor that is turned on, and a switch that is inserted between the switching transistor and sample-hold capacitor and is controlled to be turned on in synchronization with the ON-timing of the switching transistor, wherein charged voltage of the sample-hold capacitor is detected as a detection voltage. An overcurrent detection circuit is constituted in such a way that the switching transistor is compulsorily turned off when the detection voltage exceeds reference voltage. The switching circuit may correspond to a pulse-width modulation (PWM) amplifier using a pair of a PMOS transistor and an NMOS transistor that are alternately turned on or off.
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