| 摘要 |
A digital-to-analog converter includes a plurality of current cells, at least one cell in one embodiment including a pair of bipolar current switching transistors connected to a current source and a current summing bus in a current steering configuration so that one transistor is off while the other transistor is on. A temperature compensated control circuit is included for controlling the difference in base-emitter voltages of the bipolar current switching transistors based upon a temperature dependent bias voltage to compensate for a thermal voltage of the bipolar transistors. The temperature compensated control circuit preferably comprises a proportional to absolute temperature (PTAT) current source, and a steering pair of transistors connected to the PTAT current source and the pair of bipolar current switching transistors. The PTAT current source and steering transistors effectively bias the current switching transistors to account for the thermal voltage of the bipolar transistors. Method aspects of the invention are also disclosed.
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