摘要 |
A voltage margin circuit has an input that receives a control voltage for programming an output reference voltage. The control voltage is coupled through an input resistor to an operational amplifier, referenced to a voltage midway between the voltage range of the input voltage and having its output coupled to a pair of transistors, whose current flow paths are coupled to inputs of a first pair of current mirrors. Outputs of the first current mirrors pair are cross-coupled to inputs of a second current mirrors pair. Outputs of the second current mirror pair are coupled through an output resistor to a prescribed voltage. The output reference voltage is the sum of the prescribed voltage and an offset as the product of the output resistor and an output current supplied by one of the third and fourth current mirrors.
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