Efficient two-stage digital-to-analog converter using sample-and-hold circuits
AssigneeInternational Business Machines Corporation
InventorLigang Zhang
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Abstract
The present invention is a method and apparatus for converting a digital word into an analog quantity. A first plurality of signals is generated from a resistor network. A first signal is selected from the first plurality of signals based on a first half of the digital word. A second plurality of signals is generated from the resistor network using the selected first signal. A second signal is selected from the second plurality of signals based on a second half of the digital word. The second signal corresponds to the analog quantity.
Claims20
A method for converting a digital word into an analog quantity, the method comprising:
- (a) generating a first plurality of signals from a resistor network;
- (b) selecting a first signal from the first plurality of signals based on a first half of the digital word;
- (c) generating a second plurality of signals from the single resistor network using the selected first signal;
- and
- (d) selecting a second signal from the second plurality of signals based on a second half of the digital word, the second signal corresponding to the analog quantity.
A method for converting a digital word into an analog quantity, the method comprising:
- (a) generating a first plurality of signals from a resistor network;
- (b) selecting first top and bottom signals from the first plurality of signals based on a first half of the digital word;
- (c) generating a second plurality of signals from the resistor network using the selected first top and bottom signals;
- and
- (d) selecting second top and bottom signals from the second plurality of signals based on a second half of the digital word, one of the second top and bottom signals corresponding to the analog quantity.
An apparatus to convert a digital word to an analog quantity, the apparatus comprising:
- a single resistor network to generate a first plurality of signals;
- an input multiplexer coupled to receive the digital word to provide a first half and a second half of the digital word;
- a selector coupled to the resistor network to select a first signal from the first plurality of signals based on the first half of the digital word;
- a sample-and-hold circuit coupled to the selector to provide a feedback signal from the selected first signal to the resistor network, the resistor network generating a second plurality of signals;
- and
- wherein the selector selects a second signal from the second plurality of signals based on the second half of the digital word, the second signal corresponding to the analog quantity.
An apparatus to convert a digital word to an analog quantity, the apparatus comprising:
- a resistor network to generate a first plurality of signals;
- an input multiplexer coupled to receive the digital word to provide a first half and a second half of the digital word;
- a selector coupled to the resistor network to select a first top and bottom signals from the first plurality of signals based on the first half of the digital word;
- top and bottom sample-and-hold circuits coupled to the selector to provide top and bottom feedback signals from the selected first top and bottom signals to the resistor network, the resistor network generating a second plurality of signals;
- and
- wherein the selector selects second top and bottom signals from the second plurality of signals based on the second half of the digital word, one of the second top and bottom signals corresponding to the analog quantity.
Dependencies are inferred from the claim text.