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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. 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
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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. 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
A linear model of the 2nd-order closed-loop Class D amplifier
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.