class d amplifiers
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An Analysis of THD in Class D Amplifiers Huey Chian Foong; Meng Tong Tan; IEEE Asia Pacific Conference on Circuits and Systems, 2006. APCCA S 2006. Page(s):724 - 727.4-7 Dec. 2006 指指指指 指指指 ： 指 指 指指指 ： 指指指指指指指指指 指指指指指指指 體
Transcript of class d amplifiers
An Analysis of THD in Class D Amplifiers
Huey Chian Foong; Meng Tong Tan;IEEE Asia Pacific Conference on Circuits and Systems, 2006. APCCAS 2006.
Page(s):724 - 727.4-7 Dec. 2006
指導教授：易序忠學 生：楊正元
國立彰化師範大學積體電路設計研究所
Outline
THD & PSRR
Open-loop Class D amplifier
2nd-order closed-loop Class D amplifier
Dual-loop Class D amplifier
THD & PSRR
THD （ Total Harmonic Distortion ） （ ％ ） Lower is better ＜ 10 ％
PSRR （ Power Supply Rejection Rate ） （ dB ） Higher is better
Open-loop Class D amplifier
2nd-order closed-loop Class D amplifier
A linear model of the 2nd-order closed-loop Class D amplifier
Transfer function
Parameter
GPWM is determined by the ratio of the power supply voltage over the amplifier of the carrier.
GPWM is less than 5 for a larger input dynamic range and signal-to-noise ratio.
Parameter
H1 is approximately equal to –Rfb/R1.
H1 is the higher is the better.
The gain and bandwidth of the integrator has to be optimized to improve the PSRR and THD.
Frequency respond of the 2nd-order integrator
A dual-loop Class D amplifier based on 2nd-order integrator
Dual-loop transfer function
Loop-gain frequency response with dual loop feedback
THD of a single-loop feedback Class D amplifier
THD of a dual-loop feedback Class D amplifier
The end.
