| 摘要 |
A converter according to one embodiment converts an AC voltage to a regulated output current provided to a DC load of a Z-type configuration. A filter capacitor is provided to average current flowing through the load. The converter includes a rectifier network for rectifying the AC voltage and for providing a rectified voltage, and a smoothing capacitor for smoothing the rectified voltage. The converter includes a hysteretic current mode controller which controls a switching transistor based on sensed voltage and sensed current provided through an inductor coupled in series with the load. The transistor is turned on when current reaches a low valley level and is turned off when the current reaches a peak level. Operation toggles in this manner while a sensed voltage is above a predetermined level. A valley fill network may be provided to keep sensed voltage from falling below the predetermined minimum level. |
