Analog and digital dimming control for led driver
AssigneeDiodes Incorporated
InventorsADRIAN WANG, Chein-Jen Su, Welton Shih
Life of this patent
Estimating the term…
Abstract
A control circuit includes an input terminal for receiving an input signal, which maybe either a digital input signal or an analog input signal, and the control circuit is configured to provide a digital control signal in response to the input signal. The control circuit may include a mode detection circuit for determining whether the input signal is a digital signal or an analog signal and providing a mode signal, a multiplexer circuit configured to select either a digital reference signal or an analog reference signal in response to the mode signal, and a comparator configured for comparing the input signal with the reference signal selected by the multiplexer to provide the PWM control signal.
Claims20
A dimming control circuit, comprising:
- an input terminal for receiving an input signal;
- a mode detection circuit configured for determining whether the input signal is a digital signal or an analog signal and for providing a mode signal according to the determination;
- a multiplexer circuit configured for selecting a digital reference signal or an analog reference signal according to the mode signal;
- and
- a comparator circuit configured for comparing the input signal with the selected reference signal and for providing a PWM (pulse width modulation) control signal with a duty cycle according to the comparison.
A control circuit for controlling a current flow to a light-emitting diode (LED), comprising:
- an input terminal configured for receiving both a digital input signal and an analog input signal;
- and
- an output terminal configured for providing a digital signal in response to the input signal for controlling the current flow in the LED.
A linear regulator for driving a plurality of LED (light emitting diode) strings, the linear regulator comprising:
- a power terminal for receiving a DC power supply, said DC power supply also configured to provide power for the LED lamp;
- a plurality of channels, each channel including:
- an input terminal for receiving an input signal, which is either a digital dimming signal or an analog dimming signal;
- a mode detection circuit configured for determining whether the input signal is a digital signal or an analog signal and providing a mode signal;
- a multiplexer circuit configured for selecting either a digital reference signal or an analog reference signal in response to the mode signal;
- and
- a comparator circuit configured for comparing the input signal with the selected reference signal to provide a PWM (pulse width modulation) control signal with a duty cycle related to the desired output;
- and
- a constant-current regulator configured for receiving the PWM control signal to control a current flow in the LED.
Dependencies are inferred from the claim text.