Patent ID: 6927715
Filing Date: 2005-08-09
Classification: H03M

Abstract:
1. A multi-level pulse width modulation (MPWM) digital-to-analog converter for receiving a pulse code modulation (PCM) signal having n bits and then outputting a pulse width modulation (PWM) signal, comprising: a converter circuit for receiving the PCM signal to convert (n-m) bits of the PCM signal into the PWM signal, wherein m is the number of the least significant bit (LSB) signal of the PCM signal and n>m, and then generating a first input signal, a second input signal and an enabling signal; a control device for receiving the enabling signal to generate a control signal; a first output driver device having 2 a second output driver device having 2 an output device for receiving the first and the second driving signals and then outputting the PWM signal; wherein in response to the least significant bit (LSB) signal of the PCM signal, the control device selects and disables in a specified interval of each sampling cycle such that the output drivers the first and the second output driver devices are in a high impedance status, to control outputs of the first and the second output driver devices.