摘要:
A voltage regulator circuit with variable feedback is disclosed. In one embodiment, a voltage regulator includes an amplifier having a first input configured to receive a reference voltage and a second input configured to receive a feedback signal. The voltage regulator further includes first and second transistors each having respective gate terminals coupled to an output of the amplifier. A resistor network coupled to the second input of the amplifier and further coupled to the first and second transistors. The resistor network is configured to produce the feedback signal based on currents through the first and second transistors, respectively.
摘要:
A voltage regulator circuit with variable feedback is disclosed. In one embodiment, a voltage regulator includes an amplifier having a first input configured to receive a reference voltage and a second input configured to receive a feedback signal. The voltage regulator further includes first and second transistors each having respective gate terminals coupled to an output of the amplifier. A resistor network coupled to the second input of the amplifier and further coupled to the first and second transistors. The resistor network is configured to produce the feedback signal based on currents through the first and second transistors, respectively.
摘要:
A system and method for generating an analog signal is disclosed. In one embodiment, system includes a first-in, first-out (FIFO) buffer configured to receive and store a plurality of digital values written to the FIFO buffer. The system further includes a digital-to-analog converter (DAC) coupled to read the digital values from the FIFO buffer and configured to convert the digital values to an analog signal. The FIFO buffer is configured to operate in a first mode in which writes to the FIFO buffer are inhibited and current digital values stored in the FIFO buffer are provided to the DAC in a repeating sequence.
摘要:
A method and apparatus is used to provide DC stabilization and noise reduction in a multistage power amplifier. The invention uses various feedback techniques to stabilize DC levels, which helps to reduce noise. The invention also uses other techniques to reduce noise, and to reduce the noise transfer function in a power amplifier.
摘要:
A method and apparatus provides an input structure for a power amplifier. In one example, the input structure has an input network and a predriver circuit to provide an input signal to the power amplifier. The input network includes a transformer for helping to maintain a constant input impedance. The predriver includes a limiting amplifier that provides isolation between the power amplifier and the RF input. A DC feedback circuit is used by the predriver that maintains the DC level of the inverters to a desired level.
摘要:
A system and method for generating an analog signal is disclosed. In one embodiment, system includes a first-in, first-out (FIFO) buffer configured to receive and store a plurality of digital values written to the FIFO buffer. The system further includes a digital-to-analog converter (DAC) coupled to read the digital values from the FIFO buffer and configured to convert the digital values to an analog signal. The FIFO buffer is configured to operate in a first mode in which writes to the FIFO buffer are inhibited and current digital values stored in the FIFO buffer are provided to the DAC in a repeating sequence.
摘要:
A method is disclosed for controlling the operation of a low power radio platform that realizes the physical layer (PHY) with a software portion and an analog front end, the analog front end disposed between the DSP and an antenna, and realizes the MAC layer with a microcontroller unit (MCU). The DSP, analog front end and MCU are maintained in a low power mode of operation when not in data communication. When data communication is initiated, a hardware controller controls at least one hardware interface disposed between the DSP and the analog front end to initiate multiple time based tasks to transfer data to and from a buffer. During the execution of these tasks, the controller causes a task in the DSP to be initiated for processing of data in the buffers and, upon completion of at least one of the tasks, notifying the MCU of such. The controller controls the hardware interface to terminate operation when predetermined time based events have occurred. The MCU in at least one mode of operation thereof is operable to initiate the operation of the hardware controller and then convert to a low power mode of operation to await notification.
摘要:
A successive approximation analog-to-digital converter includes a capacitor array having a plurality of switch capacitors therein with varying weights, each having a common plate connected to a common node and a switched plate. A SAR controller samples an input voltage on said capacitor array in a sampling phase and redistributes the charge stored therein in a conversion phase by selectively increasing the voltage on select capacitors of the capacitor array in accordance with a SAR conversion algorithm. Circuitry controls the sampling of the input voltage by the capacitor array and is responsive to at least one applied bias current. The at least one applied bias current operates at a first level responsive to a first mode of operation of the SAR ADC and operates at a second level responsive to a second mode of operation of the SAR ADC.
摘要:
A method and apparatus is provided for use in power amplifiers for reducing the peak voltage that transistors are subjected to. A power amplifier is provided with first and second switching devices and an inductor connected between the switching devices. The switching devices are driven such that the switching devices are turned on and off during the same time intervals. Differential RF power amplifiers are also provided with inductive networks coupled at various nodes of the power amplifiers.
摘要:
A method and apparatus is used to provide DC stabilization and noise reduction in a multistage power amplifier. The invention uses various feedback techniques to stabilize DC levels, which helps to reduce noise. The invention also uses other techniques to reduce noise, and to reduce the noise transfer function in a power amplifier.