| 摘要 |
A voltage regulator circuit in an integrated circuit (IC) device such as a Complex Programmable Logic Device (CPLD) includes a reference voltage generator, a tuning circuit, and an output driver circuit. The reference voltage generator converts an external supply voltage provided to the IC device into a stable reference voltage. The tuning circuit converts the stable reference voltage into a desired internal supply voltage, such as the reduced voltage required by deep sub-micron transistors. The output driver circuit provides the desired internal supply voltage with sufficient current to properly power the circuits of the IC device. The tuning circuit includes an op-amp and resistive elements configured in a voltage divider configuration in the negative feedback loop of the op-amp. The output of the op-amp can be set to the desired internal supply voltage by properly sizing the resistive elements. By making at least one of the resistive elements adjustable, a variable internal supply voltage can be provided by the voltage regulator circuit.
|
