Abstract: A system and method is disclosed for a digital to analog converter which includes an interpolation filter to up-sample a digital signal, a cascaded digital pulse width modulation noise shaper having multiple stages to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to a reconstruction filter which outputs the analog signal. The cascaded noise shaper stages each operate using the same quantization error signal.

Abstract: A pulse width modulation (PWM) amplifier includes a first amplifier stage, a second amplifier stage, and a gain module. The first amplifier stage is configured to amplify an analog input signal in the analog and digital domains using a first pulse width modulation (PWM) generator, to provide a first stage output for coupling to a load. The gain module is configured to amplify a quantization error of the first PWM generator by a predetermined gain. The second amplifier stage is configured to spectrally shape and attenuate the amplified quantization error of the first PWM generator using a second PWM generator, to provide a second stage output for coupling to the load.

Abstract: A circuit including an analog-to-digital converter (ADC). The ADC is configured to receive an analog feedback signal and an analog input signal and generate a digital output. The circuit further includes a noise shaper. The noise shaper is configured to truncate the digital output and generate a noise shaper output having a lower number of bits than the digital output, and to shape quantization noise generated during truncation. The circuit further includes a pulse width modulation digital-to-analog converter (PWM DAC). The PWM DAC configured to process the truncated digital output of the noise shaper output and generate a PWM DAC output.

Abstract: A continuous-time delta-sigma digital-to-analog converter (DAC) includes a first delta-sigma modulator configured to quantize a most significant bit or bits of a digital input signal and produce a first quantization error signal, and a second multi-stage delta-sigma modulator configured to quantize less significant bits of the digital input signal. A first DAC is coupled to an output of the first delta-sigma modulator, and a second DAC is coupled to an output of the second noise-shaping filter. The second DAC has a greater resolution than the first DAC. A low pass output filter is coupled to a sum of an output of the first DAC and an output of the second DAC.

Abstract: An apparatus and method for generating a ramp signal includes applying a constant reference voltage to a reference capacitor and controlling charging or discharging of the reference capacitor with a programmable current generator to provide the ramp signal at a ramp signal node. The method can include, buffering the ramp signal to an output node to drive a load. When generating the ramp signal having a negative slope, the programmable current generator includes a programmable current sink coupled to the ramp signal node. When generating the ramp signal having a positive slope, the programmable current generator includes a programmable current source that is coupled between a positive power supply node and the ramp signal node. When generating the ramp signal having a bidirectional slope, the programmable current generator includes a programmable current source and a programmable current sink.

Abstract: An amplifier includes a first stage, a second stage coupled to the first stage, and a summation circuit. The first stage is configured to receive an analog input signal, convert the analog input signal to a digital signal, and output an intermediate analog output signal in response to the digital signal. The second stage is configured to output a second analog intermediate output signal based on a scaled pulse width modulation quantization error of the first stage. The summation circuit is configured to combine the first and second analog intermediate output signals to generate an amplified output signal.

Abstract: A system and method is disclosed for a digital to analog converter which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to a reconstruction filter which outputs the analog signal. The hybrid finite impulse response filter/digital to analog converter uses N-taps implemented digitally and N-tap weights implemented in analog using switched capacitors.

Abstract: A system and method is disclosed for a digital input Class D amplifier which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to an analog input Class D amplifier with digital pulse width modulation control loop. The hybrid finite impulse response filter/digital to analog converter uses N-taps implemented digitally and N-tap weights implemented in analog using resistors.

Abstract: A system and method is disclosed for a digital to analog converter which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to a reconstruction filter which outputs the analog signal.

Abstract: A system and method is disclosed for a digital to analog converter which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to a Class D delta-sigma pulse width modulation control loop.

Abstract: A system and method is disclosed for a digital to analog converter which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to a reconstruction filter which outputs the analog signal.

Abstract: A system and method is disclosed for a digital to analog converter which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to a reconstruction filter which outputs the analog signal. The hybrid finite impulse response filter/digital to analog converter uses N-taps implemented digitally and N-tap weights implemented in analog using switched capacitors.

Abstract: A system and method is disclosed for a digital to analog converter which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to a Class D delta-sigma pulse width modulation control loop.

Abstract: A system and method is disclosed for a digital input Class D amplifier which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to an analog input Class D amplifier with digital pulse width modulation control loop. The hybrid finite impulse response filter/digital to analog converter uses N-taps implemented digitally and N-tap weights implemented in analog using resistors.

Abstract: An amplifier includes a first stage, a second stage coupled to the first stage, and a summation circuit. The first stage is configured to receive an analog input signal, convert the analog input signal to a digital signal, and output an intermediate analog output signal in response to the digital signal. The second stage is configured to output a second analog intermediate output signal based on a scaled pulse width modulation quantization error of the first stage. The summation circuit is configured to combine the first and second analog intermediate output signals to generate an amplified output signal.

Abstract: An amplifier includes first and second stages. The first stage includes an input node for receiving an analog input signal, an analog digital converter for converting the analog input signal to a digital input signal, and a first switching circuit for outputting a first analog intermediate output signal in response to receiving a digital pulse width modulated signal that is based on the digital input signal. The second stage is configured to receive a pulse width modulation quantization error of the first stage, scale the pulse width modulation quantization error of the first stage by a gain factor to produce a scaled pulse width modulation quantization error of the first stage, and output a second analog intermediate output signal based on the scaled pulse width modulation quantization error of the first stage. A summation circuit combines the first and second analog intermediate output signals to generate an amplified output signal.

Abstract: A pulse width modulation (PWM) amplifier includes a first amplifier stage, a second amplifier stage, and a gain module. The first amplifier stage is configured to amplify an analog input signal in the analog and digital domains using a first pulse width modulation (PWM) generator, to provide a first stage output for coupling to a load. The gain module is configured to amplify a quantization error of the first PWM generator by a predetermined gain. The second amplifier stage is configured to spectrally shape and attenuate the amplified quantization error of the first PWM generator using a second PWM generator, to provide a second stage output for coupling to the load.

Abstract: An amplifier includes first and second stages. The first stage includes an input node for receiving an analog input signal, an analog digital converter for converting the analog input signal to a digital input signal, and a first switching circuit for outputting a first analog intermediate output signal in response to receiving a digital pulse width modulated signal that is based on the digital input signal. The second stage is configured to receive a pulse width modulation quantization error of the first stage, scale the pulse width modulation quantization error of the first stage by a gain factor to produce a scaled pulse width modulation quantization error of the first stage, and output a second analog intermediate output signal based on the scaled pulse width modulation quantization error of the first stage. A summation circuit combines the first and second analog intermediate output signals to generate an amplified output signal.

Abstract: A programmable gain controller (PGC) useful with a digital to analog converter is coupled to an input node providing a current source that is variable with a level of an input signal such as time sampled audio data, and multiple switches controlled to function as a digital gain control. Each switch is configured to selectively steer a variable fraction of the current provided by a current source to either a current sink node or to an output node of the PGC to provide at least one scaled current. An amplifier is coupled to an output of the PGC. The amplifier is configured to convert scaled current(s) to at least one output signal having an amplitude that is a function of both the input signal level and the digital gain input signal. Controlling the gain by steering current at the analog portion of the apparatus conserves circuit space and reduces noise.

Abstract: A programmable gain controller (PGC) useful with a digital to analog converter is coupled to an input node providing a current source that is variable with a level of an input signal such as time sampled audio data, and multiple switches controlled to function as a digital gain control. Each switch is configured to selectively steer a variable fraction of the current provided by a current source to either a current sink node or to an output node of the PGC to provide at least one scaled current. An amplifier is coupled to an output of the PGC. The amplifier is configured to convert scaled current(s) to at least one output signal having an amplitude that is a function of both the input signal level and the digital gain input signal. Controlling the gain by steering current at the analog portion of the apparatus conserves circuit space and reduces noise.