摘要:
In a method for a DC-DC power conversion performed by a switching mode buck voltage converter, the power conversion is split into two or more stages, and a feed-forward signal is generated by one of the stages and sent to another stage prior thereto. The feed-forward signal is generated by responding to a load current transient, such as output voltage drop, ON-duty increment or decrement occurred in the PWM control loop, error amp output swinging, and any other detectable signals in response to load current transient of the voltage converter. As a result, the performance of the DC-DC voltage converter is improved due to the prior stage modulated early in time, and both lower ripple current and peak current in steady state operations and fast response to load current transient conditions could be simultaneously obtained.
摘要:
A voltage generating circuit, which generates tri-state logic output in accordance with high, low or floating of the input node, is proposed. The present voltage generating circuit includes: a pulse generating circuit for generating a plurality of pulses; a voltage selecting circuit having a pair of NMOS transistors coupled in common source, each drain of the NMOS transistors is coupled to a current source respectively, both gates of the NMOS transistors are coupled to an input node, and the paired drain of the NMOS transistors generate a pair of voltage output; a plurality of flip-flops, which couple to drains of the NMOS transistors to lock the voltage output of the NMOS transistors in accordance with the pulses; an inner voltage-generating unit couples to the input node for providing a floating voltage level; and a plurality of switches controlled by the pulses for controlling the normal operation of the voltage selecting circuit and the conduction between the inner-voltage generating unit with the input node.
摘要:
A backlight power controller chip comprises a control circuit connected to two switches to turn on and off two display panels of a dual panel display handheld apparatus. The controller chip individually switches the two switches to control the backlight sources of the two display panels. The controller chip is available for various types of display panels.
摘要:
A voltage generating circuit, which generates tri-state logic output in accordance with high, low or floating of the input node, is proposed. The present voltage generating circuit includes: a pulse generating circuit for generating a plurality of pulses; a voltage selecting circuit having a pair of NMOS transistors coupled in common source, each drain of the NMOS transistors is coupled to a current source respectively, both gates of the NMOS transistors are coupled to an input node, and the paired drain of the NMOS transistors generate a pair of voltage output; a plurality of flip-flops, which couple to drains of the NMOS transistors to lock the voltage output of the NMOS transistors in accordance with the pulses; an inner voltage-generating unit couples to the input node for providing a floating voltage level; and a plurality of switches controlled by the pulses for controlling the normal operation of the voltage selecting circuit and the conduction between the inner-voltage generating unit with the input node.
摘要:
A frame-shifted technique is disclosed for a dynamic gamma correction method and system that comprises counting the gray levels of each frame to figure out the probability distribution of gray levels in the current frame, and determining the gamma reference voltages according to the probability distribution of gray levels of the current frame for the gamma correction of the next frame.
摘要:
A control device, which controls a power-converting module that is coupled to a light-emitting component, includes a duration detecting unit and a control signal generator. The duration detecting unit compares the duration of a predetermined logic state of a pulsating input dim control signal with a reference time period. The control signal generator is enabled by the duration detecting unit so as to generate a control signal that enables the power-converting module to generate a drive voltage for driving the light-emitting component when the duration of the predetermined logic state is not longer than the reference time period. The duration detecting unit disables the control signal generator to disable the power-converting module when the duration of the predetermined logic state is longer than the reference time period.
摘要:
A control device, which controls a power-converting module that is coupled to a light-emitting component, includes a duration detecting unit and a control signal generator. The duration detecting unit compares the duration of a predetermined logic state of a pulsating input dim control signal with a reference time period. The control signal generator is enabled by the duration detecting unit so as to generate a control signal that enables the power-converting module to generate a drive voltage for driving the light-emitting component when the duration of the predetermined logic state is not longer than the reference time period. The duration detecting unit disables the control signal generator to disable the power-converting module when the duration of the predetermined logic state is longer than the reference time period.
摘要:
The present invention provides a display panel control circuit, including: a voltage adjustment unit including a high side switch coupled between an output terminal and a high voltage source, a low side switch coupled between the output terminal and a low voltage source, and a voltage adjustment switch coupled between the output terminal and a switching node; a direction control unit, including a first diode having a cathode coupled to the switching node and an anode coupled to a voltage rising node, and a second diode having an anode coupled the switching node and a cathode coupled to a voltage falling node; a voltage rising resistor coupled between the voltage rising node and a shaping voltage source; and a voltage falling resistor coupled between the voltage falling node and the shaping voltage source.
摘要:
A multi-stage voltage regulating circuit and method with automatic temperature compensation comprises a plurality of charge-pumps, a temperature compensator, a comparative unit and a control logic circuit; wherein, the temperature compensator detects the ambient temperature and outputs a reference voltage related to the ambient temperature, the comparative unit compares the voltage of the output power source to the reference voltage output by the temperature compensator and outputs a comparative signal based on the comparison, and the control logic circuit controls the charging/discharging operations of the charge-pumps based on the comparative signal and voltages of input power sources connected to said charge-pumps to automatically regulate the voltage of the output power source.
摘要:
The present invention provides a display panel control circuit, including: a voltage adjustment unit including a high side switch coupled between an output terminal and a high voltage source, a low side switch coupled between the output terminal and a low voltage source, and a voltage adjustment switch coupled between the output terminal and a switching node; a direction control unit, including a first diode having a cathode coupled to the switching node and an anode coupled to a voltage rising node, and a second diode having an anode coupled the switching node and a cathode coupled to a voltage falling node; a voltage rising resistor coupled between the voltage rising node and a shaping voltage source; and a voltage falling resistor coupled between the voltage falling node and the shaping voltage source.