摘要:
A data modulation circuit has an adder adding an input signal, and an output signal of a memory device; and an output circuit part discriminating and quantizing the output signal of the adder by a predetermined threshold value. The memory device receives and holds the output signal of the adder and a predetermined signal, and supplies the held signals to the adder as an output signal of the memory device.
摘要:
Methods and apparatus for implementing and/or using amplifiers and performing various amplification related operations are described. The methods are well suited for use with, but not limited to, switching type amplifiers. The methods and apparatus described herein allow for the use of switching amplifiers while reducing and/or compensating for distortions that the use of such amplifiers would normally create. The described methods and apparatus can be used alone or in combination with various novel signaling schemes which can make it easier to compensate for the non-ideal behavior of switching amplifiers in such a way as to enable practical application in wireless transmission and/or other applications.
摘要:
A system and method of creating a highly efficient digital amplifier which can take either analog or digital inputs, and produce a high power accurate representation of the input to drive speakers or other low impedance load is described. The system employs a transition detector and delay unit which allows the comparator of the signal modulator to ignore its inputs for a pre-determined number of subsequent clock cycles once an output transition has been detected. Through the use of faster clocks and variable clock cycle skips upon the comparator's output transition, finer resolution of the feedback's clock period for noise-shaping purposes is achieved. Finer resolution of the clock period allows the present invention to employ a more aggressive noise-shaping than previously possible. In another aspect of the invention; additional delta-sigma modulator noise suppression is obtained by using the common bridge implementation of the power output stage with the improvement of configuring the bridge to create a 3-state condition instead of the conventional 2 states. By controlling the two halves of the bridge independently of one another, an output with 3 states makes for improved noise shaping performance.
摘要:
An oversampling type digital-to-analog converter which has a light gradient overload and a high signal-to-noise ratio in spite of a comparatively low sampling frequency.In a digital-to-analog converter wherein the difference between an oversampled digital input signal and a feedback signal is taken, such differences are integrated, the integral value is quantized to obtain the feedback signal, and part of the feedback signal is used as an analog output signal; a circuit for the quantization is constructed of a circuit which converts the integral value into a digital signal smaller in the number of bits than the digital input signal, and the feedback signal is obtained by integrating the outputs of the quantization circuit by means of a digital integral circuit.
摘要:
A noise shaping module includes a first addition module that receives an N-bit digital input signal, where N is an integer greater than one. A first filter module generates a first filtered output signal based on an output signal of the first addition module. A truncation module generates an M-bit truncated output signal based on the first filtered output signal, where M is an integer less than N. A second filter module generates a second filtered output signal based on the M-bit truncated output signal. The second filtered output signal is an input to the first addition module.
摘要:
A noise shaping circuit and method for operating the same includes a first addition module that receives a digital input signal. A first filter module generates a first filtered output signal based on an output of the first addition module. A truncation module generates a truncated output signal based on first filtered output signal. A second filter module generates a second filtered output signal based on the truncated output signal. The second filtered output signal is an input to the first addition module.
摘要:
A method for generating an analog signal based on samples representing the analog signal includes feeding the samples into a delta-sigma modulator, the delta-sigma modulator outputting a sequence of bits, and introducing a non-linear time-discrete function into a feedback loop between a quantizer element and a delta element of the delta-sigma modulator, where arguments of the non-linear time-discrete function include a current bit and at least one bit previous to the current bit.
摘要:
An analog signal outputting circuit comprises two unit analog circuits for outputting an analog signal, corresponding to levels “−1” or “1”, and a low-pass filter for smoothing the analog signal output from the two unit analog circuits, as selected by codes output from the four-valued delta-sigma modulator. In case the input signal is −2 or +2, outputs of the unit analog circuits are summed together to output an analog signal corresponding to −2 or +2. In case the input signal is −1 or +1, outputs of the unit analog circuits are alternately used to output an analog signal corresponding to −1 or +1 to reduce the non-linearity error resulting from variations in the analog devices.
摘要:
A Delta-Sigma modulator is disclosed, which has a Delta adder, a Sigma adder, a first latch, a second latch and a feedback generator, wherein the feedback generator provides a feedback signal to the Delta adder based on a pre-stage data signal provided by the first latch, so that the Delta adder provides a pre-stage addition signal. The Sigma adder performs an accumulation to provide an accumulative signal to the first latch, so that the first latch provides a pre-stage data signal to the second latch to enable the second latch to output a digital output signal.
摘要:
A system and method of creating a highly efficient digital amplifier which can take either analog or digital inputs, and produce a high power accurate representation of the input to drive speakers or other low impedance load is described. The system employs a transition detector and delay unit which allows the comparator of the signal modulator to ignore its inputs for a pre-determined number of subsequent clock cycles once an output transition has been detected. Through the use of faster clocks and variable clock cycle skips upon the comparator's output transition, finer resolution of the feedback's clock period for noise-shaping purposes is achieved. Finer resolution of the clock period allows the present invention to employ a more aggressive noise-shaping than previously possible. In another aspect of the invention, additional delta-sigma modulator noise suppression is obtained by using the common bridge implementation of the power output stage with the improvement of configuring the bridge to create a 3-state condition instead of the conventional 2 states. By controlling the two halves of the bridge independently of one another, an output with 3 states makes for improved noise shaping performance.