公开(公告)号：US10980090B1

公开(公告)日：2021-04-13

申请号：US16850958

申请日：2020-04-16

Applicant: Richtek Technology Corporation

Inventor： Yu-Min Chen ,  Isaac Y. Chen ,  Leng-Nien Hsiu

IPC: H05B37/00 ,  H05B45/10 ,  H05B45/325 ,  H05B45/385 ,  H05B45/38 ,  H05B45/375

Abstract: AN LED driving apparatus includes a power stage circuit and a dimming control circuit. The power stage circuit drives an LED circuit. The dimming control circuit includes a duty ratio conversion circuit, a digital-to analog conversion (DAC) circuit, an error amplifier (EA) circuit and a modulation control circuit. The duty ratio conversion circuit converts a PWM dimming signal to a digital duty ratio signal. The DAC circuit converts the digital duty ratio signal to an analog reference signal. The EA circuit generates an error amplified signal according to a difference between the analog reference signal and an output current related signal. The modulation control circuit generates a PWM control signal according to the error amplified signal, to control the power switch, such that the output current relates to a dimming duty ratio, whereby the dimming control circuit dims the LED circuit according to the PWM dimming signal.

公开(公告)号：US20210112639A1

公开(公告)日：2021-04-15

申请号：US16850958

申请日：2020-04-16

Applicant: Richtek Technology Corporation

Inventor： Yu-Min Chen ,  Isaac Y. Chen ,  Leng-Nien Hsiu

IPC: H05B45/10 ,  H05B45/325

Abstract: AN LED driving apparatus includes a power stage circuit and a dimming control circuit. The power stage circuit drives an LED circuit. The dimming control circuit includes a duty ratio conversion circuit, a digital-to analog conversion (DAC) circuit, an error amplifier (EA) circuit and a modulation control circuit. The duty ratio conversion circuit converts a PWM dimming signal to a digital duty ratio signal. The DAC circuit converts the digital duty ratio signal to an analog reference signal. The EA circuit generates an error amplified signal according to a difference between the analog reference signal and an output current related signal. The modulation control circuit generates a PWM control signal according to the error amplified signal, to control the power switch, such that the output current relates to a dimming duty ratio, whereby the dimming control circuit dims the LED circuit according to the PWM dimming signal.