Load current sensing circuit for sensing load current of direct current converter, has simulation stage forming resistor proportional to time-averaged resistor, and measurement circuit measuring current flowing through resistor with voltage

摘要

The circuit has a comparator stage (26) determining difference voltage between direct current (DC) components of pulse width modulation signals. An impedance simulation stage (28) forms a resistor that is proportional to a time-averaged resistor of high-level side and low-level side power transistors (T1, T2), which are connected in series between supply terminals. The determined difference voltage is applied to the impedance simulation stage. A measurement circuit (30) measures current flowing through the resistor of the impedance simulation stage with the difference voltage. An independent claim is also included for a method for sensing a direct current converter load current of a direct current converter.