Patent application number | Description | Published |
20090115524 | OUTPUT STAGE CIRCUIT AND OPERATIONAL AMPLIFIER THEREOF - The present invention relates to an output stage circuit and an operational amplifier thereof. In the output stage circuit, one of a gate of a transistor is coupled to a gate of a bias transistor and a level shifter in response to a small signal outputted from an amplifying circuit in the operational amplifier. In addition, a gate voltage of the bias transistor is controlled by a voltage generating circuit to control a DC bias of the transistor of the output stage circuit. Therefore, extra frequency compensating components for compensating the transistor of the output stage circuit is no longer necessary, and saving circuit layout area and cost can be achieved by the present invention. | 05-07-2009 |
20090115527 | OUTPUT STAGE CIRCUIT AND OPERATIONAL AMPLIFIER THEREOF - The present invention relates to an output stage circuit and an operational amplifier thereof. In the output stage circuit, one of a gate of a transistor is coupled to a gate of a bias transistor and a level shifter in response to a small signal outputted from an amplifying circuit in the operational amplifier. In addition, a gate voltage of the bias transistor is controlled by a voltage generating circuit to control a DC bias of the transistor of the output stage circuit. Therefore, there is no need extra frequency compensating component for compensating the transistor of the output stage circuit, and to save circuit layout area and cost can be achieved by the present invention. | 05-07-2009 |
20110032132 | DELTA-SIGMA ANALOG-TO-DIGITAL CONVERSION APPARATUS AND METHOD THEREOF - A delta-sigma analog-to-digital conversion apparatus for receiving an analog input signal to generate a digital output signal includes a subtracting unit, a quantizer, and a feedback unit. The subtracting unit is utilized for performing a subtraction function to generate a subtracted signal according to the analog input signal and a feedback signal. The quantizer is coupled to the subtracting unit and utilized for performing quantization to generate a quantized signal according to the subtracted signal. The feedback unit is coupled between the subtracting unit and the quantizer, and utilized for providing the feedback signal to the subtracting unit according to the quantized signal. The subtracting unit is arranged to reduce signal input swing of the quantizer. | 02-10-2011 |
20110102225 | METHOD FOR REDUCING CURRENT CONSUMPTION OF DIGITAL-TO-ANALOG CONVERSION, AND ASSOCIATED TRI-STATE CURRENT DIGITAL-TO-ANALOG CONVERTER - A method for reducing current consumption of digital-to-analog conversion includes: monitoring logical states of a set of differential digital inputs, wherein the set of differential digital inputs are utilized for controlling at least one tri-state current Digital-to-Analog Converter (DAC) cell of a tri-state current DAC, and the tri-state current DAC cell has a positive output current state, a zero output current state and a negative output current state; and when the logical states of the set of differential digital inputs instruct the tri-state current DAC cell should output no positive/negative current, controlling the tri-state current DAC cell to switch to the zero output current state, temporarily decreasing a direct current passing through a middle path of the tri-state current DAC cell. An associated tri-state current DAC is also provided, where the tri-state current DAC includes: the at least one tri-state current DAC cell; and a control device. | 05-05-2011 |
20110187571 | DELTA-SIGMA ANALOG-TO-DIGITAL CONVERSION APPARATUS AND METHOD THEREOF - A delta-sigma analog-to-digital conversion apparatus for receiving an analog input signal to generate a digital output signal includes a subtracting unit, a quantizer, and a feedback unit. The subtracting unit is utilized for performing a subtraction function to generate a subtracted signal according to the analog input signal and a feedback signal. The quantizer is coupled to the subtracting unit and utilized for performing quantization to generate a quantized signal according to the subtracted signal. The feedback unit is coupled between the subtracting unit and the quantizer, and utilized for providing the feedback signal to the subtracting unit according to the quantized signal. The subtracting unit is arranged to reduce signal input swing of the quantizer. | 08-04-2011 |