Methods and devices for adaptive voltage steadying
AssigneeSTMicroelectronics S.r.l.
InventorsNicola Lupo, Enrico Mammei, Michele Bartolini, Stefano Colli
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Abstract
A method to drive a digital to analog converter (DAC), the method including setting a reference current for the DAC with a reference current source, a base voltage being responsive to changes in a reference voltage at a reference node coupled with the reference current source; sensing a change in the reference voltage; and adaptively steadying the base voltage based on the change in the reference voltage to maintain proportionality between an output current of the DAC and the reference current.
Claims20
An adaptive current driving system, the adaptive current driving system comprising:
- a digital to analog converter (DAC) comprising:
- an input to receive a digital code comprising a number N bits;
- and
- N DAC cells, each of the N DAC cells comprising a bipolar transistor, and each of the N DAC cells being configured to be activated depending on a state of a corresponding bit of the digital code;
- a reference stage comprising a reference bipolar transistor coupled at a collector with a reference current source and being coupled at a base with the bases of the bipolar transistors of the N DAC cells;
- a voltage sensing stage configured to sense a reference voltage at a reference node and to generate a voltage signal corresponding with the reference voltage;
- a buffer coupled with the voltage sensing stage and configured to generate a buffered voltage signal based on the voltage signal;
- and
- an output stage configured to output a base voltage depending on the buffered voltage signal.
A digital to analog converter (DAC), comprising:
- a voltage sensing stage configured to sense a reference voltage at a reference node and to generate a voltage signal corresponding with the reference voltage;
- a buffer coupled with the voltage sensing stage and configured to generate a buffered voltage signal based on the voltage signal;
- and
- an output stage configured to output a base voltage depending on the buffered voltage signal.
A method of driving a digital to analog converter (DAC), the method comprising:
- providing a reference current for the DAC, a reference voltage being generated based on the reference current, a base voltage being responsive to changes in the reference voltage;
- and
- adaptively steadying the base voltage based on changes in the reference voltage.
Dependencies are inferred from the claim text.