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US 7,583,216 B2Granted
Adjustable DAC and applications thereof
AssigneeSigmatel, Inc.
InventorsMatthew D. Felder, Marcus W. May, Michael R. May
Life of this patent
Estimating the term…
Abstract
A digital to analog converter (DAC) includes at least one digital to analog conversion module and a gated termination. The at least one digital to analog conversion module is coupled to convert at least one bit of a digital signal into an analog signal. The gated termination is coupled to an analog output of the at least one digital to analog conversion module to provide a first termination when a termination selection signal is in a first state and to provide a second termination when the termination selection signal is in a second state.
Claims20
A digital to analog converter (DAC) comprises:
- at least one digital to analog conversion module coupled to convert at least one bit of a digital signal into an analog signal, the digital to analog converter comprising:
- a first current source coupled to a first supply voltage source;
- a first switch;
- and
- a second switch, wherein, when the at least one bit is in a first state, the first switch is enabled to steer current of the first current source to a dump node and, when the at least one bit is in a second state, the second switch is enable to steer the current of the first current source to an analog output;
- a third switch operable to couple the dump node to a second supply voltage source when the at least one bit is in the first state, wherein voltage of the second supply voltage source is less than a voltage of the first supply voltage source and
- a power regulator that produces the second supply voltage, wherein the power regulator responds accordingly to maintain regulation of the second supply voltage as the current from the dump node changes;
- and
- a gated termination coupled to the analog output of the at least one digital to analog conversion module to provide a first termination when a termination selection signal is in a first state and to provide a second termination when the termination selection signal is in a second state.
6 more elements
A digital to analog converter (DAC) comprises:
- a plurality of digital to analog conversion modules coupled to convert a digital signal into an analog signal, wherein a digital to analog conversion module of the plurality of digital to analog conversion modules includes:
- a current source coupled to provide a first current when the DAC is in a first mode and to provide a second current when the DAC is in a second mode, wherein the second current is greater than the first current;
- a first switch;
- a second switch, wherein, when at least one bit of the digital signal is in a first state, the first switch is enabled to steer the first or second current to a dump node and, when the at least one bit is in a second state, the second switch is enable to steer the first or second current to an analog output;
- and
- a power regulator that produces the second supply voltage, wherein the power regulator responds accordingly to maintain regulation of the second supply voltage as the current from the dump node changes.
3 more elements
A method, comprising:
- in response to determining a first digital to analog conversion module is in a first mode, providing a first current from a current source;
- in response to determining a first digital to analog conversion module is in a second mode, providing a second current from the current source, the second current greater than the first current;
- receiving a digital signal at the first digital to analog conversion module;
- in response to determining a first bit of the digital signal is in a first state, steering the first current or the second current to a dump node;
- and
- in response to determining the first bit of the digital signal is in a second state, steering the first current or the second current to an analog output;
- and
- regulating the second supply voltage to maintain a voltage as the current from the dump node changes.
5 more elements
Dependencies are inferred from the claim text.