Circuit calibration system and method
AssigneeRambus Inc.
InventorsElad Alon, Bruno Garlepp, Vladimir Stojanovic, Andrew Ho, Fred Chen
Life of this patent
Estimating the term…
Abstract
An integrated circuit device includes one or more calibration paths including one or more devices. A signal generator is coupled to at least one calibration path and configured to provide the calibration path with a calibration signal having known characteristics. A controller is coupled to the signal generator and the calibration path and configured to adjust the signal generator and at least one parameter associated with at least one device in the calibration path.
Claims36
1-3. (canceled)
An integrated circuit, comprising:
- a calibration path including a device;
- a signal generator, comprising an oversampled digital-to-analog converter (DAC), coupled to the calibration path and configurable to provide the calibration path with a calibration signal;
- and
- a controller coupled to the signal generator and the calibration path, the controller configurable to adjust the signal generator and a parameter associated with the device in the calibration path in response to an output signal provided by the integrated circuit so as to calibrate the device in the calibration path;
- wherein the oversampled DAC, comprises:
- a digital pulse width modulator (PWM) configurable to generate a digital waveform;
- and
- an n-bit DAC coupled to the PWM and configurable to convert the digital waveform into an analog calibration signal.
An integrated circuit, comprising:
- a calibration path including a device;
- a signal generator comprising an oversampled digital-to-analog converter (DAC), coupled to the calibration path and configurable to provide the calibration path with a calibration signal;
- and
- a controller coupled to the signal generator and the calibration path, the controller configurable to adjust the signal generator and a parameter associated with the device in the calibration path in response to an output signal provided by the integrated circuit so as to calibrate the device in the calibration path;
- wherein the oversampled DAC, comprises:
- a digital pulse width modulator (PWM) configurable to generate a digital waveform;
- and
- an digital-to-analog converter coupled to the PWM for converting the digital waveform into the calibration signal.
The circuit of claim 1 1, wherein the switch is coupled to an input of the device in the calibration path.
(canceled)
A receiver calibration system, comprising:
- a switch coupled to receive an input signal and a calibration signal;
- a sampler coupled to the switch and configurable to receive the input signal or the calibration signal from the switch and provide an output;
- a signal generator, comprising an oversampled digital-to-analog converter (DAC), configurable to provide the calibration signal to the switch based on a calibration control signal;
- a controller coupled to the signal generator and an output of the sampler, the controller configurable to provide the calibration control signal in response to the sampler output;
- and
- an offset cancellation circuit coupled to the controller and the sampler, the offset cancellation circuit configurable to adjust an input sampling parameter in the sampler based on an adjustment signal from the controller.
(canceled)
A receiver calibration system, comprising:
- a switch coupled to receive an input signal and a calibration signal;
- a sampler coupled to the switch and configurable to receive the input signal or the calibration signal from the switch and provide an output;
- a signal generator, comprising an oversampled digital-to-analog converter (DAC), configurable to provide the calibration signal to the switch based on a calibration control signal;
- a controller coupled to the signal generator and an output of the sampler, the controller configurable to provide the calibration control signal in response to the sampler output;
- wherein the oversampled DAC, comprises:
- a digital pulse width modulator (PWM) configurable to generate a digital waveform;
- and
- an n-bit DAC coupled to the PWM and configurable to convert the digital waveform into an analog calibration signal.
A receiver calibration system, comprising:
- a switch, disposed in a pre-amplifier, coupled to receive an input signal and a calibration signal;
- a sampler coupled to the switch and configurable to receive the input signal or the calibration signal from the switch and provide an output;
- a signal generator configurable to provide the calibration signal to the switch based on a calibration control signal;
- a controller coupled to the signal generator and an output of the sampler, the controller configurable to provide the calibration control signal in response to the sampler output;
- wherein the input signal is a differential input signal and the pre-amplifier, comprises:
- a first differential pair;
- a first current source;
- a second differential pair;
- a second current source;
- and
- a first switch configurable to couple the first differential pair to the first current source so as to couple the differential input signal to the sampler;
- and
- a second switch configurable to couple the second differential pair to the second current source so as to couple the calibration signal to the sampler.
A system, comprising:
- a transmitting device coupled to a receiving device by a communication link;
- the transmitting device including:
- a signal generator configurable to generate a calibration input signal based on a calibration control signal;
- a transmitter coupled to the signal generator and configurable to transmit a calibration output signal to the receiver;
- and
- a controller;
- and
- the receiving device including a sampler coupled to the transmitter via the communication link and configurable to sample the calibration output signal;
- wherein the controller is coupled to the sampler via the communication link and is configurable to generate the calibration control signal based on an output of the sampler.
(canceled)
A method of calibrating an integrated circuit, comprising:
- providing a calibration path in the integrated circuit with a calibration signal, including:
- generating a pulse width modulated digital waveform;
- converting the digital waveform into an analog representation of a bit stream;
- filtering the bit stream to extract an average signal level for the bit stream;
- generating the calibration signal from the average signal level;
- and
- providing the calibration signal to the calibration path;
- adjusting a parameter associated with a device in the calibration path based on a device output in response to the calibration signal;
- and
- adjusting the calibration signal based on the device output so as to calibrate the device.
A system for calibrating an integrated circuit, comprising:
- means for providing a calibration path in the integrated circuit with a calibration signal;
- means for adjusting a parameter associated with a device in the calibration path based on a device output in response to the calibration signal;
- and
- means for adjusting the calibration signal based on the device output so as to calibrate the device;
- wherein the means for providing a calibration path in the integrated circuit with a calibration signal comprises:
- means for generating a pulse width modulated digital waveform;
- means for converting the digital waveform into an analog representation of a bit stream;
- means for filtering the bit stream to extract an average signal level for the bit stream;
- means for generating the calibration signal from the average signal level;
- and
- means for providing the calibration signal to the calibration path.
A computer readable medium containing data representing a circuit that includes:
- a calibration path including a device;
- a signal generator coupled to the calibration path and configurable to provide the calibration path with a calibration signal;
- and
- a controller coupled to the signal generator and the calibration path, the controller configurable to adjust the signal generator and a parameter associated with the device in the calibration path in response to an output signal provided by the integrated circuit so as to calibrate the device in the calibration path;
- wherein the signal generator comprises an oversampled digital-to-analog converter that includes:
- a digital pulse width modulator (PWM) configurable to generate a digital waveform;
- and
- an digital-to-analog converter coupled to the PWM for converting the digital waveform into the calibration signal.
Dependencies are inferred from the claim text.