Digital-to-analog converter
AssigneeNovatek Microelectronics Corp.
InventorKuo-Yu Chou
Life of this patent
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Abstract
A digital-to-analog converter (DAC) is disclosed, which provides different bias voltages to the most significant bits (MSBs) and the least significant bits (LSBs) of the digital signal. These two bias voltages can be adjusted according to the match among the current source cells, and maintain a particular proportional relationship. The DAC further includes a bias converter for receiving the first bias voltage, and adjusting the second bias voltage according to the match among the current source cells.
Claims20
A digital-to-analog converter (DAC) suitable for a segment type combining a thermometer-code portion and a binary-weighted portion, used for thermometer-encoding a MSB portion of an input-code and generating multiple corresponding thermometer-codes, and binary-weighting a LSB portion of said input-code and generating a plurality of binary-weighted codes, wherein said DAC comprises:
- a plurality of current source cells for providing currents, wherein a first portion of said current source cells receives a first bias voltage and provides a current corresponding to said thermometer-codes, and a second portion of said current source cells receives a second bias voltage and provides a current corresponding to said binary-weighted codes, wherein said first bias voltage and said second bias voltage are adjusted according to the match among said current source cells, and keep a particular proportional relationship.
A DAC, comprising:
- a first set of current source cells which comprise a plurality of the first current source cells to receive a first bias voltage and to provide a current according to a first code;
- a second set of current source cells which comprise a plurality of the second current source cells to receive a second bias voltage and to provide a current according to a second code;
- and
- a bias converter, disposed between said first set of current source cells and the second set of current source cells, for adjusting both said first bias voltage and said second bias voltage and maintaining a particular proportional relationship therebetween according to the match between said first current source cells and said second current source cells.
Dependencies are inferred from the claim text.