Data transmitter and method therefor
AssigneeInternational Business Machines Corporation
InventorsJohn Lock Creigh, Michel Ferry, Thomas Ashford Hughes, Jr., Scott David Huss
Life of this patent
Estimating the term…
Abstract
A data transmitter is provided which performs digital to analog conversion, convolution with an arbitrary finite impulse response, and smoothing of the output functions without requiring a separate anti-aliasing low pass filter. To implement the data transmitter, a digital input data value is convolved with a desired impulse response. The coefficients of the desired finite impulse response filter are chosen to create a first or second derivative of an output of the data transmitter. Then, the derivative is integrated so that a resulting signal output from the data transmitter is a smooth signal which does not require further filtering.
Claims27
A data transmitter, comprising:
- an input circuit for receiving an input signal;
- a filter circuit for performing a convolution of the input signal using a second derivative of a desired impulse response of the data transmitter, the filter circuit being coupled to the input circuit for receiving the input signal and the filter circuit providing an intermediate output signal;
- and
- an integrator coupled to the filter circuit for receiving the intermediate output signal, the integrator integrating the intermediate output signal to provide an output signal having the desired impulse response of the data transmitter.
A data transmitter, comprising:
- input means for receiving a plurality of digital data values;
- a convolutional digital to analog converter coupled to the input means for receiving the plurality of digital data values, the convolutional digital to analog converter receiving an offset current and a reference current, the convolutional digital to analog converter providing an analog output signal, and the convolutional digital to analog converter comprising:
- a filter circuit for performing a convolution of the plurality of digital data values and a derivative of a desired impulse response of the data transmitter, the filter circuit being coupled to the input circuit for receiving the plurality of digital data values and the filter circuit providing an intermediate output signal;
- and
- an integrator coupled to the filter circuit for receiving the intermediate output signal, the integrator integrating the intermediate output signal to provide the analog output signal having the desired impulse response of the data transmitter;
- an output buffer for providing the analog output signal;
- a signal measurement circuit coupled to the output buffer for receiving the analog output signal, the signal measurement circuit measuring an amplitude of the analog output signal and providing a measurement signal in response thereto;
- an offset canceling circuit coupled to the signal measurement circuit to receive the measurement signal, the offset current source generating the offset current in response thereto;
- and
- an amplitude control circuit coupled to the signal measurement circuit to receive the measurement signal, the reference current source generating the reference current in response thereto.
A method for implementing a data transmitter, comprising the steps of:
- receiving an input signal;
- performing a convolution of the input signal and a second derivative of a desired impulse response of the data transmitter using a filter circuit;
- enabling the filter circuit to provide an intermediate output signal;
- and
- integrating the intermediate output signal to provide an output signal having the desired impulse response of the data transmitter.
Dependencies are inferred from the claim text.