METHOD AND CIRCUIT FOR REDUCING RIPPLE OF CURRENT OUTPUT BY CURRENT SOURCE

摘要

Disclosed are a method and circuit for reducing a ripple of a current output by a current source. The circuit for reducing a ripple of a current output by a current source comprises a tube with adjustable impedance and a control circuit. The control circuit detects a direct current output by the current source to obtain a first signal which is in proportion to the direct current, and by comparing an instantaneous value of the first signal with an amplitude value of a set signal, controlling the increase of the impedance of the tube with adjustable impedance when the instantaneous value of the first signal is greater than the amplitude value of the set signal, so as to enable the amplitude value of the first signal to not exceed the amplitude value of the set signal and then enable the amplitude value of the current output by the current source to not exceed the amplitude value of the set current of the set signal, so that the purpose of reducing the ripple of the direct current output by the current source is finally achieved.

主权项

1. A circuit for reducing a ripple of a current output by a current source, wherein an output terminal of the current source is connected to a load and a current output by the current source has a ripple, wherein the circuit comprises an adjustable impedance tube and a control circuit;
the adjustable impedance tube is connected in series with the load through a first terminal and a second terminal of the adjustable impedance tube, and a control terminal of the adjustable impedance tube is connected to an output terminal of the control circuit; and the control circuit is configured to, acquire a direct current output by the current source and obtain a first signal in proportion to the direct current; acquire an average value of the direct current output by the current source and obtain a setting signal associated with the average value of the direct current; and output a control signal for increasing an impedance of the adjustable impedance tube in a case that an instantaneous value of the first signal is sensed to be greater than an amplitude value of the setting signal; wherein the control signal adjusts the impedance of the adjustable impedance tube through controlling a voltage or a current at the control terminal of the adjustable impedance tube.