VOLTAGE GENERATOR WITH CURRENT SOURCE COMPENSATED FOR AN ERROR CURRENT OPERABLE OVER A WIDE VOLTAGE RANGE

摘要

In one embodiment, a regulator circuit for generating a regulated output voltage Vout has an error amplifier using a pair of bipolar transistors at its front end. The error amplifier compares the regulated output voltage to a reference voltage Vref. A precision current source draws a first current through a user-selected set resistance to generate the desired Vref. The regulator circuit controls a power stage to cause Vout to be equal to Vref. The base current into one of the bipolar transistors normally distorts the current through the set resistance. A base current compensation circuit is coupled to the current source to adjust the first current by a value equal to the base current to offset the base current. Therefore, Vref is not affected by the base current. The error amplifier may be in a linear regulator or a switching regulator. The compensation circuit may be used in other applications.

主权项

1. A circuit comprising:
a first current source generating a first current and having an output terminal, a first voltage being generated at the output terminal; the output terminal being connected to a first device which introduces a first error current, which offsets the first voltage from a target first voltage; and a correction circuit connected to a second terminal of the first current source, the correction circuit generating a second current approximately equal to the first error current, which modifies the first current to compensate for the first error current so as to cause the first voltage to be approximately the target first voltage, wherein operation of the correction circuit is not dependent on a magnitude of the first voltage.