System and method for current digital-to-analog converter
AssigneeInfineon Technologies AG
InventorsMatteo Dalla Longa, Francesco Conzatti
Life of this patent
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Abstract
In accordance with an embodiment, a circuit includes a current digital-to-analog converter (DAC) having a current switching network coupled to a current DAC output, a first cascode current source coupled between a first supply node and the current switching network, a second cascode current source between a second supply node and the current switching network, and a shorting switch coupled between a first cascode node of the first cascode current source, and a second cascode node of the second cascode current source.
Claims20
A circuit comprising:
- a current digital-to-analog converter (DAC), wherein the current DAC comprises
- a current switching network coupled to a current DAC output,
- a first cascode current source coupled between a first supply node and the current switching network,
- a second cascode current source between a second supply node and the current switching network, and
- a shorting switch coupled between a first cascode node of the first cascode current source, and a second cascode node of the second cascode current source.
A method of operating a current digital-to-analog converter (DAC) comprising a current switching network coupled to a current DAC output, a first cascode current source coupled between a first supply node and the current switching network, a second cascode current source between a second supply node and the current switching network, and a shorting switch coupled between a first cascode node of the first cascode current source, and a second cascode node of the second cascode current source, the method comprising:
- configuring the current switching network according to a current DAC input value while the shorting switch is closed;
- opening the shorting switch after configuring the current switching network to cause a current proportional to the current DAC input value to flow through the current DAC output;
- and
- closing the shorting switch a predetermined period of time after opening the shorting switch to inhibit the current proportional to the current DAC input value from flowing through the current DAC output.
A continuous-time delta-sigma converter, comprising:
- at least one continuous-time integrator;
- a comparator coupled to an output of the at least one continuous-time integrator;
- and
- a current DAC comprising:
- a first current source coupled to an output of the current DAC via a first switch at a first current source output node,
- a second current source coupled to the output of the current DAC via a second switch at a second current source output node,
- a shorting switch coupled between a first internal node of the first current source, and a second internal node of the second current source, and
- a programmable pulse generator coupled to a control node of the shorting switch, wherein the programmable pulse generator is configured to gate an output current of the current DAC by opening the shorting switch for a predetermined period of time.
Dependencies are inferred from the claim text.