VCC Charge and Free-Wheeling Detection via Source Controlled MOS Transistor

摘要

A driver circuit using a power converter allows free-wheeling detection and/or provision of supply voltage. A circuit controls a switching state of a power switch. A first port of the switch is coupled to an inductor. The circuit is coupled to a control port of the switch wherein the control port of the switch is different from the first port of the switch. The circuit comprises a unit generating a signal for controlling the switching state of the switch wherein the signal is provided to the control port of the switch. Furthermore, the circuit comprises free-wheeling sensing means to detect an oscillation of a voltage at a measurement port of the switch wherein the measurement port of the switch is different from the first port of the switch and wherein the oscillation of the voltage at the measurement port indicates free-wheeling of the inductor.

主权项

1) A control circuit configured to re-charge supply voltage provisioning means and configured to control the switching state of a power switch; wherein the supply voltage provisioning means are configured to provide a supply voltage to a gate of the power switch; the control circuit comprising
a control switch configured to
couple an output of the power switch to ground, when an input of the control switch is coupled to the output of the power switch, to put the power switch to an on-state; anddecouple the output of the power switch from ground, to put the power switch to an off-state; and charging circuitry configured to enable a charging current flowing from the output of the power switch to the supply voltage provisioning means and configured to disable a current flowing from the supply voltage provisioning means to the output of the power switch, when an input of the charging circuitry is coupled to the output of the power switch and when an output of the charging circuitry is coupled to the gate of the power switch and to the supply voltage provisioning means; wherein the charging current is derived from a current flowing through an input-to-output capacitance arranged between an input and the output of the power switch.