Headroom compensation circuit for voltage converter

摘要

A headroom compensation circuit for a voltage converter for ensuring that there is adequate headroom voltage to enable accurate operation of the current sense amplifier sensing the output current of the converter, the headroom compensation circuit comprising an error amplifier for comparing an output voltage of the converter to a reference voltage to set the converter output voltage; and a circuit for providing a bias current to an input of the error amplifier when a supply voltage to the current sense amplifier within a predefined threshold of the converter output voltage to cause the error amplifier to reduce the converter output voltage thereby to increase the headroom voltage for the current sense amplifier, said headroom voltage being defined as a voltage between the supply voltage to the current sense amplifier and said converter output voltage.