| 摘要 |
<p>A circuit (30) for measuring current flowing through a load (10) driven by a pulse width modulation (PWM) circuit (20) in response to PWM control signals (VG1, VG2). The circuit includes a transformer (40) having primary (44, 46) and secondary (48) windings, with the primary winding connected to the load. Current cancellation circuitry (35) is coupled to the secondary winding for applying a cancellation current to the secondary winding and to provide an output which is indicative of a level of current through the load. An inverter (72) coupled to the current cancellation circuitry output provides an inverted current cancellation circuitry ouptut. First and second switches (U3, U4) selectively couple one of the current cancellation circuitry output and the inverted current cancellation circuitry output to a load current output (VO) which provides an output indicative of the level of current through the load during both static and dynamic load current conditions.</p> |
