| 摘要 |
A current steering circuit includes a multitude of current stages each including an associated current source transistor, and first and second cascode transistors coupled in series with the associated current source transistor. The first and second cascode transistors respectively receive first and second reference voltages and are biased such that a voltage appearing across any terminal pairs of the transistors is less than a predefined value. Each current stage includes a first switch supplying the current flowing through the transistors to a first resistive load in response to a control signal, and a second switch supplying the current to a second resistive load in response to a complement of the control signal. An amplifier responsive to an analog multiplexer's output provides a biasing voltage to each of the current stages. The analog multiplexer supplies a different output voltage in response to different counts of a counter.
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