Operating circuit for LEDs, having voltage measurement

摘要

The invention relates to an operating circuit for an LED series, having: a converter, particularly a DC-DC converter, having a controllable switch (S1) and an inductor (LBUCK) for converting an input voltage (Vin) fed to the operating circuit into a supply voltage for the LED series; —a control unit (SR) for driving the switch (S1); —a secondary-side inductor (L2) coupled to the inductor (LBUCK); —an envelope curve demodulator (30) for detecting the envelope curve of the voltage (V′LED) present at the secondary-side inductor (L2); and—a compensating circuit (31) for compensating an error caused by the envelope curve demodulator (30) relating to the detection of the envelope curve.

主权项

1. An operating circuit for an LED system, comprising:
a DC voltage converter, with a controllable switch (S1) and an inductor (LBuck) for converting an input voltage (Vin) supplied to the operating circuit into a supply voltage for the LED system; a control unit (SR) for controlling the switch (S1); a secondary-side inductor (L2) coupled to the inductor (LBuck); an envelope-curve demodulator (30) for detecting the envelope curve of the voltage (V′LED) present in the secondary-side inductor (L2); and a compensation circuit (31) for compensating an error relating to the detection of the envelope curve caused by the envelope-curve demodulator (30), wherein the envelope-curve demodulator (30) comprises a first diode (D70) for rectification of the voltage (V′LED) present in the secondary-side inductor (L2); and the compensation circuit (31) comprises a second diode (D71) for compensation of a detection error caused by the diode (D70).