摘要:
The present invention provides a transistor switch on a light emitting device channel, the transistor switch receiving a control voltage VG. A current source circuit controls the current on the light emitting device channel, the current source circuit requiring a minimum voltage VR for normal operation. The present invention further provides a dynamic headroom controller circuit which compares a voltage VS at a current outflow end of the transistor switch with the voltage VR to determine the relationship between the voltage VS and the voltage VR when the control voltage VG is higher than a reference voltage VH, and adjusts the voltage difference between the voltage VS and the voltage VR accordingly.
摘要:
A boost converter includes a load disconnect switch connected between a voltage input terminal and an inductor, a power switch connected to the inductor by a switching node, a diode connected between the switching node and a voltage output terminal, and an output capacitor connected to the voltage output terminal to provide an output voltage. A protection apparatus is connected to the load disconnect switch, switching node and power switch to monitor the voltage at the switching node and the output voltage to provide open circuit and short circuit protection for the boost converter.
摘要:
A boost converter includes a load disconnect switch connected between a voltage input terminal and an inductor, a power switch connected to the inductor by a switching node, a diode connected between the switching node and a voltage output terminal, and an output capacitor connected to the voltage output terminal to provide an output voltage. A protection apparatus is connected to the load disconnect switch, switching node and power switch to monitor the voltage at the switching node and the output voltage to provide open circuit and short circuit protection for the boost converter.
摘要:
A LED display system includes multiple LEDs, a power converter to produce a supply voltage for the LEDs, and multiple drivers to drive the LEDs. According to the maximum one of the forward voltages of the LEDs, the drivers provides a feedback signal for the supply voltage control, and the feedback signal is amplified or digitized to reduce the voltage drop in the global power line.
摘要:
The invention provides a current control circuit and a current control method. The current control circuit controls a current supplied to a current-controlled device according to a conduction control signal. The current control circuit includes: a conduction control switch coupled to the current-controlled device, for determining whether to conduct the current according to the conduction control signal; and a plurality of current control switches connected to one another in series and coupled to the conduction control switch, for controlling a magnitude of the current.
摘要:
A LED display system includes multiple LEDs, a power converter to produce a supply voltage for the LEDs, and multiple drivers to drive the LEDs. According to the maximum one of the forward voltages of the LEDs, the drivers provides a feedback signal for the supply voltage control, and the feedback signal is amplified or digitized to reduce the voltage drop in the global power line.
摘要:
The present invention provides a transistor switch on a light emitting device channel, the transistor switch receiving a control voltage VG. A current source circuit controls the current on the light emitting device channel, the current source circuit requiring a minimum voltage VR for normal operation. The present invention further provides a dynamic headroom controller circuit which compares a voltage VS at a current outflow end of the transistor switch with the voltage VR to determine the relationship between the voltage VS and the voltage VR when the control voltage VG is higher than a reference voltage VH, and adjusts the voltage difference between the voltage VS and the voltage VR accordingly.
摘要:
The present invention discloses a light emitting device array billboard and a control method thereof. The light emitting device array billboard includes a light emitting device array circuit, plural line switch circuits, plural channel switch circuits, plural ghost image compensation switch circuits, and a control circuit. The control circuit operates the line switch circuits and the channel switch circuit to turn ON a selected light emitting device for a duty period in a lighting period, and operates the plural ghost image compensation switch circuits to electrically connect a channel node corresponding to the selected light emitting device to a ghost image compensation voltage after the lighting period. The control circuit further adjusts a channel operation signal according to a gray scale compensation signal, to turn ON the selected light emitting device for a gray scale compensation period in addition to the duty period.
摘要:
The present invention discloses a light emitting device control circuit and a control method thereof, for controlling a light emitting device array display. The present invention controls not only the conduction timing and duration of one or more selected light emitting devices in the light emitting device array display, but also controls the current flowing through the selected light emitting devices by a variable current source, such that in one frame of a given length, the resolution of the brightness of the light emitting devices is increased.
摘要:
The present invention discloses a light emitting device array billboard and a row switch circuit and a control method thereof. The light emitting device array billboard includes a light emitting device array circuit, plural row switch circuits, plural column driver circuits, and a control circuit. The light emitting device array circuit includes plural light emitting devices arranged by columns and rows. Each row switch circuit determines whether to electrically connect a row conduction voltage to the corresponding row node or to discharge charges at the corresponding row node through a discharging path according to a row selection signal. Each column driver circuit determines whether or not to electrically connect a column conduction voltage to the corresponding column node according to a column selection signal. The control circuit provides the row selection signal and the column selection signal to the row switch circuits and the column driver circuits.