Patent ID: 6400163
Filing Date: 2002-06-04
Classification: G01R,H03K

Abstract:
A circuit arrangement for monitoring and controlling an electronic switch provided for controlling a load and load current flowing through the load during turn-on intervals and for driving the load, the switch having a substantially linear resistance behavior during parts of its turn-on state and the operating point of the switch being located in this part of the turn-on state during the load control, the circuit arrangement comprising:a modulation signal generator for generating a modulation signal modulating the load current flowing through the electronic switch, the electronic switch being driven by a control signal driver; a first voltage measuring device for measuring a first voltage drop across the electronic switch caused by the modulation signal; a second voltage measuring device for measuring a second voltage drop across the electronic switch caused by the load current, the first and second voltage drops being supplied to an analog-to-digital converter for calculating an output signal based on the first and second voltage drops; and an evaluation unit for determining the load current from the modulation signal and the output signal of the analog-to-digital converter.