| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital input class-D amplifier which involves a small error in D/A conversion and which can drive a load by means of a drive waveform faithful to an input digital signal. SOLUTION: A DEM decoder 10 outputs the time-series digital signals DP(k) (k =0 to M-1) and DN(k) (k =0 to M-1) having a density of "1" or "0" conforming to input digital signals Din. An error integrator 30 integrates the input analog signals of two positive and negative phases which are respectively the sum of the lines of the signals DP(k) (k =0 to M-1) and the sum of the lines of the signals DP(k) (k =0 to M-1) while receiving negative feedback from both ends of the load 100. A PWM modulation circuit 40 generates the pulses VDp and VDn of a pulse width corresponding to the integrated result, and pre-drivers 51 and 52 and an output buffer 60 drive the load 100 on the basis of the pulses. COPYRIGHT: (C)2009,JPO&INPIT
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