公开(公告)号：EP1049247B1

公开(公告)日：2005-08-03

申请号：EP99830247.5

申请日：1999-04-27

Applicant: STMicroelectronics S.r.l.

Inventor： Masini, Marco ,  Franchini, Luigi ,  Labbe, Eric

IPC: H03F3/217

CPC classification number: H03F3/217

公开(公告)号：EP1049247A1

公开(公告)日：2000-11-02

申请号：EP99830247.5

申请日：1999-04-27

Applicant: STMicroelectronics S.r.l.

Inventor： Masini, Marco ,  Franchini, Luigi ,  Labbe, Eric

IPC: H03F3/217

CPC classification number: H03F3/217

Abstract: A class-D amplifier comprising an input integrating stage (Op-Amp, R1, C), a modulating stage (PWM) of the integrated input signal output by said integrating stage, using as a carrier an alternate waveform ( Vtr ) of a frequency ( fsw ), sufficiently higher than the frequency band of the analog input signal, outputting a digital signal switching between a positive voltage (+ Vcc ) and a negative voltage ( -Vcc ), and whose average value ( Vo ) represents an amplified replica of the input analog signal, an output power stage (BUFFER), producing an output digital signal ( Vout ), a feedback line constituted by a resistor ( R2 ) connected between the output of said output power stage (BUFFER) and an input node of an operational amplifier ( Op-Amp ) constituting said integrating stage, and a low pass filter reconstructing an output analog signal ( V o), further comprises a delay stage (DELAY Td ), functionally coupled in the direct path of propagation of said digital signal from the output of said PWM stage to an input of said output power stage (BUFFER), delaying said digital signal by a delay ( Td ) whose value is defined in function of a desired broadening of the bandwidth and in consideration of the corresponding restriction of the range of variation of the duty-cycle of the output digital signal.

Abstract translation: 一种D类放大器，包括输入积分级（Op-Amp，R1，C），由所述积分级输出的积分输入信号的调制级（PWM），使用频率的交替波形（Vtr）作为载波 （fsw），足够高于模拟输入信号的频带，输出在正电压（+ Vcc）和负电压（-Vcc）之间切换的数字信号，其平均值（Vo）表示放大的副本 输出模拟信号，输出功率级（BUFFER），产生输出数字信号（Vout）的反馈线，由连接在所述输出功率级（BUFFER）的输出端和输出节点之间的电阻器（R2）构成的反馈线 构成所述积分级的运算放大器（Op-Amp）和重构输出模拟信号（Vo）的低通滤波器还包括延迟级（DELAY Td），功能上耦合在所述数字信号的传播的直接路径中 所述PWM级的输出 到所述输出功率级（BUFFER）的输入端，将所述数字信号延迟延迟（Td），延迟（Td）的值被定义为期望的带宽宽度的功能，并且考虑到占空比的变化范围的相应限制 - 输出数字信号的循环。