Shenzhen China Star Optoelectronics Technology Co., Ltd.

Xin-Ming Gao

Xiang Yang

Po-shen Lin

Liang-chan Liao

The present invention provides a driving circuit, a backlight module and a display apparatus using the same. The driving circuit comprises a first inductor, a second inductor, a first power switch, a second power switch, a driving circuit unit and a push-pull circuit. The first inductor and the second inductor are connected between the light-emitting diodes and a power supply. The first power switch is connected between the first inductor and the light-emitting diodes. The second power switch is connected between the second inductor and the light-emitting diodes. The push-pull circuit is connected to the first power switch and the second power switch. The driving circuit unit is connected to the push-pull circuit. An electrolytic capacitor or a capacitor having high capacitance can be omitted in this invention.

Backlight module and display apparatus

A boost circuit for an LED (Light Emitting Diode) backlight driver circuit is disclosed; said boost circuit includes a PWM (Pulse Width Modulation) chip, a second capacitor, and a signal processing circuit. A VCC pin of the PWM chip is coupled to the input node, and the PWM chip is utilized to generate a PWM signal. One end of the second capacitor is coupled to an output pin of the PWM chip, and the second capacitor is utilized to filter out a direct current component of the PWM signal. One terminal of the signal processing circuit is coupled to the second capacitor, and another terminal thereof is coupled to a gate of the switch. The signal processing circuit is used to adjust the filtered PWM signal for generating corresponding high levels and low levels. A regulator is omitted in the present invention, therefore reducing costs.

Boost circuit for LED backlight driver circuit

The present invention provides a self-driven synchronous rectification boost converter having high step-up ratio. The self-driven synchronous rectification boost converter having high step-up ratio has a first switch receiving a pulse driving signal, a first winding, a second winding and a synchronous rectification circuit constructed by an auxiliary winding and a second switch. The first winding inducts a reverse voltage when the first switch is repeatedly switched on and off. The reverse voltage then is raised via the second winding, and the auxiliary winding cooperates with a switch circuit to switch on/off the second switch according to an inducted voltage, so as to achieve an object of synchronous rectification. Under a condition of outputting high current, the present invention can greatly reduce power-consumption of rectifying and enhance efficiency.

Self-driven synchronous rectification boost converter having high step-up ratio

The present invention provides a self-driven synchronous rectification boost converter. The self-driven synchronous rectification boost converter has a first switch receiving a pulse driving signal, a first winding and a synchronous rectification circuit constructed by an auxiliary winding and a second switch. The first winding stores energy when the first switch is switched on and releases energy when the first switch is switched off to achieve boosting. In the meantime, the auxiliary winding cooperates with a switch circuit to switch on/off the second switch according to a voltage inducted from the first winding, so as to achieve an object of synchronous rectification. Under a condition of outputting high current, the present invention can greatly reduce power-consumption of rectifying and enhance efficiency.

Self-driven synchronous rectification boost converter

The present invention provides a display device and an LED backlight driving circuit thereof. The LED backlight driving circuit includes a plurality of LED light strings connected in parallel; a switch module including switches; a power module, and a switching control module. The switching control module includes: a driving unit connected to the switches; a current detection unit connected to the switches; an ON time detection unit connected to the driving unit; a reference unit, the reference unit supplying a reference value; multipliers, each of which has two input terminals respectively connected to the ON time detection unit and the current detection unit to receive a ON time value of a corresponding one of the switches and a voltage signal indicating the current of the switch; and comparison units, each of which has two input terminals respectively connected to the reference unit and an output terminal of a corresponding one of the multipliers. Each of the comparison units has an output terminal connected to the driving unit. The driving unit controls the ON time of the switch corresponding to the comparison unit according to an output result of the comparison unit.

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Shenzhen, China

Xin-Ming Gao