US Patent No. 10,602,575

CURRENT MODULATION CIRCUIT, A DRIVING CIRCUIT, AND A METHOD FOR DRIVING A LIGHTING LOAD WITH CURRENT MODULATION


Patent No. 10,602,575
Issue Date March 24, 2020
Title Current Modulation Circuit, A Driving Circuit, And A Method For Driving A Lighting Load With Current Modulation
Inventorship Johan-Paul Marie Gerard Linnartz, Eindhoven (NL)
Kumar Arulandu, Eindhoven (NL)
Aleksandar Sevo, Eindhoven (NL)
Haimin Tao, Eindhoven (NL)
Assignee SIGNIFY HOLDING B.V., Eindhoven (NL)

Claim of US Patent No. 10,602,575

1. A current modulator circuit for modulating a drive current through a lighting load, comprising:a current modulating element for modulating the light output of the lighting load based on a data input signal, wherein the current modulating element is adapted to be connected in series with the lighting load; and
a feedback system for controlling the current modulating element thereby to implement modulation of the current through the lighting load, wherein the feedback system comprises,
a first feedback control path having as input a voltage across the current modulating element, wherein the first feedback control path comprises a comparator arrangement for comparing a measured voltage across the current modulating element with a reference voltage and a low-pass filter between an output of the comparator arrangement and a control input of the current modulating element; and
a second feedback control path having as input the data input signal, wherein the second feedback control path is based on measurement of the current through the current modulating transistor, wherein the current through the current modulating transistor is compared with the data input signal, and the result is provided to one terminal of the low pass filter through a high pass filter.