Onkyo Corporation

Kazuhiro Hida

Joji Kasai

Mamoru Sekiya

Yoshitaka Handa

Sou Fujioka

Hiroyuki Hirano

A switching amplifier including a PWM circuit, a driver, a switching output circuitand an LPFis provided with a fluctuation detection circuitfor detecting fluctuations in the power supply voltage. The fluctuation detection circuitincludes detection resistorsandconnected in series between a positive power supplyand a negative power supply. A fluctuating signal RPL occurring at a fluctuation detection terminalis supplied to the inverted input terminal of a differential amplifierof a non-inverted amplifier circuit. The non-inverted amplifier circuitinverts the fluctuating signal RPL, mixes the inverted fluctuating signal into the input signal e, amplifies the mixed signal, and supplying the amplified signal to the PWM circuit

Switching amplifier

In a switching power supply of the present invention, when a voltage output from start-up means is greater than a driving voltage produced by output means, the voltage from the start-up means is provided to control means, whereby the switching power supply can be started up reliably. Furthermore, when the voltage output from the start-up means is less than the driving voltage produced by the output means, the current path is blocked in the start-up means so that no voltage is provided to the control means from the start-up means, whereby it is possible to reduce the power consumption during the steady operation.

Growing community of inventors

Neyagawa, Japan

Kazuhiro Hida