| 摘要 |
A voltage reference circuit that produces an output offset from a supply voltage by approximately two volts, the output being relatively stable in the face of vacillations in the external power supplies. The first leg of the circuit utilizes devices having differing Vt's to produce an internal reference of one volt below Vdd. In a first embodiment of the invention, the second leg has a first device that is diode connected, wherein the gate receives the internal reference and the source is at the high power supply, and a second high Vt diode connected device. The two devices are matched to have the same overdrive current, which is at a voltage that is a function of the difference between the gate-to-source voltage of the first device and the threshold voltage of the first device. Thus, the output is a function of the overdrive to, and the diode drop across, the second high-Vt device.
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