The invention provides an adaptive output current
ripple removing circuit and method. The method comprises that a negative end
voltage of an LED load is detected; when the negative end
voltage is lower than a set
voltage, a first
constant current source is switched off, a second
constant current source is switched on and discharges a compensation
capacitor, the compensation voltage is reduced, theoutput current is reduced, and the negative end voltage of the LED load is increased; and when the negative end voltage of the LED load is greater than the set voltage, the first
constant current source is switched on, the second
constant current source is switched off, the first
constant current source charges the compensation
capacitor, the compensation voltage is increased, the output currentis increased, and the negative end voltage of the LED load is reduced. Only the minimal value of the output
ripple voltage is detected, and the method and device are suitable for
ripple removing application of
silicon controlled
rectifier light modulation and linear output; and overheating protection does not influence work of a pre-stage
system, flickering is avoided from influencing the experience, and heat loss of an
MOSFET can be controlled independently.