Adjustable current limit switching regulator with constant loop gain

摘要

A switching regulator is configured to provide a regulated voltage to a load while maintaining a substantially maximum output current limit, the switching regulator having a loop gain. In accordance with one aspect the switching regulator comprises: a circuit for adjusting the maximum output current limit in response to a programmable signal independently of the loop gain. In accordance with another aspect, the switching regulator comprises: a resistance sensing element for providing the current output of the regulator, and having a resistance which varies with temperature; and a circuit for maintaining the output current limit at a level independent of the temperature of the sensing element. In addition, in accordance with one aspect, a method of providing a regulated voltage to a load is disclosed in which a substantially maximum output current limit of a switching regulator is maintained. In one aspect the method comprises: adjusting the maximum output current limit in response to a programmable signal independently of the loop gain. In accordance with a second aspect, the method comprises: maintaining the output current limit at a level independent of the temperature of the sensing element and a constant transient response to load perturbations as a function of temperature and current limit setting.

主权项

1. An integrated circuit comprising:
a switching regulator configured to provide a regulated voltage to a load while maintaining a substantially maximum output current limit, the switching regulator including:
an output circuit (a) comprising a switch circuit that is configured to be coupled to a power source and an output, (b) a duty cycle adjustable voltage clamp circuit; and (c) a voltage clamp adjustment circuit; the output circuit being configured to provide a feedback signal through a feedback path that is function of the regulated voltage;wherein the switching regulator defines a loop gain; andan input to the switching regulator integrated circuit for applying an adjustment signal from a source external to the voltage clamp adjustment circuit in the presence of no slope compensation so as to modify the nominal maximum output current limit to a desired value while maintaining the regulated voltage without significantly affecting the loop gain.