Abstract: 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.

Abstract: An automatic contrast compensation apparatus for an OLED display comprises a photo detector, an OLED driver, a safety clamping circuit, and a solar cell. When the intensity of environmental light increased, the photo detector sends a signal to the OLED driver to increase the brightness of the OLED display and for which, the solar cell provides the extra power for the OLED driver to improve the displaying performance of the OLED display in a power-saving manner. The safety clamping circuit prevents the OLED driver from over-current from the solar cell.

Abstract: 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.