Monolithic Power Systems, Inc.

Chengdu Monolithic Power Systems Co., Ltd.

Yunping Lang

Yuancheng Ren

Junming Zhang

Huijie Zhao

Rui Wang

Li Lian

Xiaoming Li

Huafei Ding

Jinyan Lin

A class D audio amplifier having: an audio control circuit configured to provide a switching signal based on an input signal and a reference signal; an input capacitor coupled between the input signal and the first input terminal of the audio control circuit; an inductor having a first terminal coupled to the switching terminal of the audio control circuit, and a second terminal; an output capacitor having a first terminal coupled to second terminal of the inductor and a second terminal coupled to a load; and a noise suppression circuit having a first terminal coupled to the first input terminal of the audio control circuit, and a second terminal coupled to the switching terminal of the audio control circuit, wherein the noise suppression circuit charges the input capacitor and the output capacitor to reach a preset value.

Class D audio amplifier with noise suppression and the method thereof

The present technology relates generally to a closed-loop power stage and audio amplifier circuits comprising the same. The present technology further provides a method for controlling an amplifier circuit. The closed-loop power stage is configured to receive a PWM input signal having a first frequency and a first duty cycle, a power supply voltage, and a bias signal related to the power supply voltage, and to output a square-wave signal having a second frequency and a second duty cycle. The closed-loop power stage comprises a feedback loop which is configured to regulate the second duty cycle of the square-wave signal in response to a variation in the power supply voltage. The audio amplifier circuit comprising the closed-loop power stage may have a stable output voltage and thus have good power supply rejection performance.

Audio amplifier with closed-loop power

The embodiments of the present invention illustrate a means for digitally controlling a converter system and associated method. Wherein the means for digitally controlling a converter system comprises a means for generating a digital error signal according to an output voltage of the converter system and a reference voltage, a means for generating a digital control signal according to a digital reference signal and the digital error signal, and a means for generating a PWM signal according to the digital control signal in order to control the converter system. The means for digitally controlling a converter system and associated method at least alleviate the problem of limit-cycle oscillation, and promote the performance of system transient response and accuracy.

Means and associated methods for digitally controlling converter systems

The embodiments of the present invention disclose a high power-supply rejection ratio (PSRR) amplifier circuit. The amplifier circuit comprises a low dropout regulator, a negative charge pump and an amplifier. The output voltages of the negative charge pump and the low dropout regulators don't track the change of input voltage. Therefore the amplifier circuit has high PSRR.

High power-supply rejection ratio amplifying circuit

The present invention discloses a Class-D power amplifier and control method thereof. In one embodiment, the amplifier feeds back the signal at the output node to the inverting input of the comparator, and provides a high frequency triangular wave signal to the non-inverting input of the comparator. In addition, the non-inverting input of the comparator may be coupled to an offset voltage, while the inverting input of the comparator may be coupled to a fixed-frequency rectangular wave signal, a feedback signal which is derived from the output stage and an input signal. In use, the switching frequency may be at least substantially fixed, so as to reduce the influence on the system caused by electromagnetic interruption (EMI). Further, the control circuit is simple, and some devices can be integrated.

Growing community of inventors

Hangzhou, China

Yunping Lang