Samsung Electronics Co., Ltd.

Digital and Analog Co., Ltd.

Other

Goog-Chun Cho

Jae-Hoon Jeong

Jae-Wook Lee

Bo-Hyung Cho

Chung-Gil Yang

Chang-Gyun Kim

Jong-Hu Park

A class D amplifier and a method of pulse width modulation are provided. The class D amplifier includes a sigma delta modulator, a reference signal generator, a pulse width modulator and an amplifier. The sigma delta modulator converts an M bit input signal into N bit pulse code modulation data (M and N are integers and M&#x3e;N). The reference signal generator counts a system clock and generates an N bit reference signal having 2data blocks in a sampling period of the pulse code modulation data. The pulse width modulator generates a plurality of pulse width modulation signals having at least two switching periods within the sampling period of the pulse code modulation data. The pulse width modulation signals have pulse widths varied based on a unit time interval of the reference signal. The unit time interval corresponds to one of the data blocks of the reference signal.

Class D amplifier and a method of pulse width modulation

A class-D power amplifier, which prevents excessive response phenomenon from occurring when returning to a steady state from an abnormal state and an amplification method of the class-D power amplifier are provided. The class-D power amplifier prevents an integral control circuit or a proportional integral control circuit from becoming saturated by using sub-negative feedback loop operations, without using a high-capacity output blocking switch in an initial state or an abnormal state. Thus, suppressing pop noise due to the excessive response phenomenon caused when the class-D power amplifier returns to the steady state from the initial state or the abnormal state and reducing power consumption.

Class-D power amplifier capable of eliminating excessive response phenomenon when returning to a steady state from an abnormal state and an amplification method thereof

Disclosed is a digital PWM input D class amplifier by PWM negative feedback. The amplifier includes: digital modulation part for modulating PCM signal of input audio to PWM signal; pulse width generating and correcting part for comparing difference between the PWM signal and output signal negatively fed back, with PWM ramp signal to generate PWM switching signal; output part for generating an amplified output audio signal in response to the PWM switching signal of the pulse width generating and correcting part; and voltage negative feedback loop for negatively feeding back signal of the output part and decreasing a harmonic component to provide the signal to the pulse width generating and correcting part. Thus, the invention compares the negative feedback signal with positive/negative (+/&#x2212;) saw tooth PWM ramp signal to control On/Off time period of switching transistor and the PWM pulse width and thereby enhance the linearity of the output PWM.

Digital PWM input D class amplifier by PWM negative feedback

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Gunpo-si, South Korea

Goog-Chun Cho