摘要:
A pipeline analog to digital (A/D) converter for converting an analog input signal into a digital representation of the analog signal. The pipeline A/D converter has a sample and hold stage, the sample and hold stage sampling and holding the analog input signal and outputting a sampled and held signal. The pipeline A/D converter also has a first analog signal converter stage, the first analog converter stage producing a digital output based on the sampled and held signal, from which a most significant bit of the digital representation of the analog input signal is derived. The first analog converter stage produces a residue signal based on a comparison of the analog input signal and an analog representation of the digital output. The pipeline A/D converter has at least one additional stage, the additional stage producing a subsequent digital output based on the residue signal produced by the first analog signal converter stage, at least one bit which is less significant than the most significant bit being derived from the subsequent digital output.
摘要:
An integrated circuit includes a variable delay circuit configured to generate at least one delayed clock signal based on a first clock signal and a first control signal. The integrated circuit includes a control circuit configured to generate a count value based on a second input signal and a second control signal. The first clock signal is a first version of the at least one delayed clock signal. At least one of the second input signal and the second control signal is a second version of the at least one delayed clock signal and the count value is indicative of a frequency characteristic of the at least one delayed clock signal. The integrated circuit is configured to monotonically vary the first control signal over a range of values and the count value is determined for individual values of the control signal.
摘要:
A pipeline analog to digital (A/D) converter having a sample and hold stage which samples an analog input signal during a primary clock signal and holds during a secondary clock signal. The A/D converter has an analog signal converter stage which converts and latches the sampled and held voltage signal into a digital output during the secondary clock signal. The analog signal converter stage generating a residue signal based on a comparison of the sampled and held voltage signal and from an analog representation of the digital output, the analog signal converter stage samples the sampled and held voltage signal during the secondary clock signal and holds the residue signal during the primary clock signal. The primary and secondary clock signals together form a two phase nonoverlapping clock having a regular period with a length defined by the duty cycles of the primary and secondary clock signals. The duty cycle of the primary clock signal being less than the duty cycle of the secondary clock signal. According to another aspect of the invention, an A/D converter has a sample and hold stage which samples an analog input signal during a first clock signal and holds a sampled voltage signal during a second clock signal. The A/D converter has an analog signal converter stage, which converts and latches the sampled and held voltage signal into a digital output during the second clock signal. The analog signal converter stage generating a residue signal based on a comparison of the analog input signal and from an analog representation of the digital output, the analog signal converter stage samples the analog input signal during the first clock signal and holds the residue signal during a third clock signal. The first clock signal and the second clock signal form a first two phase nonoverlapping clock and the third clock pulse signal forms a second two phase nonoverlapping clock with a fourth clock pulse signal. The fourth clock signal having a duty cycle of less than, greater than or equal to 50% of the period of the second nonoverlapping clock, and the pulse of the first clock signal and the pulse of the second clock signal both overlapping with the pulse of the fourth clock signal. The duty cycle of the first clock signal is optionally less than the duty cycle of the second clock signal.
摘要:
A circuit and method for calibrating a VCO (voltage controlled oscillator) is disclosed. In one embodiment, a circuit includes a VCO and a bias control circuit coupled to a tail node of the VCO. An amplitude control unit may also be coupled to the tail node, wherein the amplitude control unit is configured to determine the amplitude of a VCO output signal based on a voltage present on the tail node. The amplitude control unit may also be configured to generate a bias voltage based on the amplitude of the VCO output signal and a target voltage. The bias control circuit may be coupled to receive the bias voltage from the amplitude control unit and may be further configured to adjust the voltage on the tail node based on the received bias voltage.
摘要:
A phase signal select circuit includes a supporting path coupled to a tri-state inverter circuit. The supporting path reduces effects of hysteresis on signal transfer. An apparatus includes at least one input node responsive to a respective one of at least one input signal. The apparatus includes at least one circuit coupled to a respective one of the at least one input node and coupled to an output node. Individual ones of the at least one circuit are configured to provide a version of the respective input signal to the output node in response to a first state of a respective select signal. The apparatus includes at least one second circuit coupled to a respective one of the at least one circuit. The at least one second circuit is configured to toggle nodes of the at least one circuit in response to a second state of the respective select signal.
摘要:
A receive interface circuit includes a duty cycle adjustment circuit that adjusts the duty cycle of a reference clock signal based, at least in part, on a selected number of duty cycle adjustment units and a selected range of duty cycle adjustment. The duty cycle adjustment circuit may select as the reference clock signal one of a clock signal and at least a lower version of the clock signal in parallel with the duty cycle adjustment.
摘要:
A pipeline analog to digital (A/D) converter. The pipeline A/D converter having a sample and hold amplifier stage, the sample and hold amplifier stage sampling an analog input signal during a first clock pulse signal. The pipeline A/D converter having an analog signal converter stage, the analog signal converter stage sampling the analog input signal during a first clock pulse signal. According to another aspect of the invention, the pipeline A/D converter converts an analog input signal into a digital representation of the analog input signal. The pipeline A/D converter has a clock generator, the clock generator generating a first clock pulse signal, a second clock pulse signal and a third clock pulse signal. A sample and hold stage samples an analog input signal during the pulse of the first clock signal and holds a sampled voltage signal during the pulse of the second clock signal. A first analog signal converter stage converts and latches the sampled and held voltage signal into a digital output during the pulse of the second clock signal, a most significant bit of the digital representation of the analog input signal being derived from the digital output. The first analog signal converter stage generating a residue signal based on a comparison of the analog input signal and from an analog representation of the digital output. The first analog signal converter stage sampling the analog input signal during the pulse of the first clock signal and holding the residue signal during the pulse of the third clock signal.
摘要:
A phase signal select circuit includes a supporting path coupled to a tri-state inverter circuit. The supporting path reduces effects of hysteresis on signal transfer. An apparatus includes at least one input node responsive to a respective one of at least one input signal. The apparatus includes at least one circuit coupled to a respective one of the at least one input node and coupled to an output node. Individual ones of the at least one circuit are configured to provide a version of the respective input signal to the output node in response to a first state of a respective select signal. The apparatus includes at least one second circuit coupled to a respective one of the at least one circuit. The at least one second circuit is configured to toggle nodes of the at least one circuit in response to a second state of the respective select signal.
摘要:
A receive interface circuit includes a duty cycle adjustment circuit that adjusts the duty cycle of a reference clock signal based, at least in part, on a selected number of duty cycle adjustment units and a selected range of duty cycle adjustment. The duty cycle adjustment circuit may select as the reference clock signal one of a clock signal and at least a lower version of the clock signal in parallel with the duty cycle adjustment.
摘要:
A pipeline ADC (Analog to Digital Converter) unit is provided that has a first and a second multi-stage portion. The first multi-stage portion has a first plurality of converter stages for converting a first analog signal to a first digital signal having a first digital resolution. The second portion has a second plurality of converter stages to convert a second analog signal to a second digital signal having a second digital resolution. The second plurality includes the first plurality. The pipeline ADC unit selectively uses either the first plurality of stages alone, or the second plurality. The pipeline ADC unit may be used in a WLAN (Wireless Local Area Network) communication device.