Abstract: A liquid crystal display (LCD) includes a backlight driving module. The backlight driving module includes a boost circuit, a control chip, and a ferrite bead. The boost circuit includes a metal-oxide-semiconductor-field-effect transistor (MOSFET). The control chip includes a pulse width modulation (PWM) input pin and provides PWM signals to turn on and turn off the MOSFET. One end of the ferrite bead is connected to the PWM input pin, and another end is connected to the gate of the MOSFET.

Abstract: A power switching circuit is connected to an external power source, a battery, and a load. The power switching circuit includes a voltage converter, a prevention unit, a detecting unit, and a switch. The voltage converter converts a first primary voltage supplied by the external power source to a secondary voltage. The prevention unit allows the secondary voltage to be transmitted to the load, the secondary voltage powering the load. The detecting unit generates a first level signal when the external power source fails to output the first primary voltage. The switch is turned on to transmit a second primary voltage supplied by the battery to the load and the prevention unit in response to the first level signal. The second primary voltage powers the load. The prevention unit prevents the second primary voltage from being transmitted to the voltage converter.

Abstract: A driving circuit for backlight LED comprises a power input, a control module, a voltage promotion module and a filter circuit module. The filter circuit is connected between the power input and the voltage promotion module. The filter circuit module is configured to filter ripple voltage signals from the power source and periodic voltage echo wave signals from the voltage promotion module to eliminate the “water wave” on a LCD display.

Abstract: A circuit with power saving function connected to a LCD includes a display signal output module, to output a display control signal; a boosting circuit; a Content Adaptive Backlight Control (CABC) control module, to output a CABC signal; and a combining circuit, connected between the display signal output module and the CABC control module, to combine the display control signal outputted by the display signal output module and the CABC signal outputted by the CABC control module, then output a combined signal to an input port of the boosting circuit. The boosting circuit is configured to boost the combined signal and output a boosted combined signal to the LCD, thereby changing the backlighting of the LCD to save energy.

Abstract: A printed circuit board (PCB) includes at least two vias and at least two bonding pads corresponding to the vias. Each bonding pad is arranged on the surface of the PCB around the corresponding one of the at least two vias. Between two adjacent bonding pads, a through hole is arranged for preventing molten solder overflowing from one bonding pad to the other.