Voltage converter and driving method for use in a backlight module
AssigneeChunghwa Pictures Tubes, Ltd.
InventorsKe-Horng Chen, Chi-Lin Chen, Yao-Yi Yang, Ling Li, Chia-Lin Liu, Chi-Neng Mo
Life of this patent
Estimating the term…
Abstract
A voltage converter for use in a backlight module stores energy of an input voltage using an inductor and outputs a plurality of output voltages accordingly. The charging path of the inductor is controlled according to the first output voltage so that the first output voltage can be stabilized. The discharging paths from the inductor to other output voltages are controlled according to the differences between other output voltages and the first output voltage so that other output voltages can also be stabilized.
Claims14
A voltage converter for use in a backlight module, comprising:
- an inductor configured to store an energy of an input voltage;
- a power switch configured to control a charging path of the inductor according to a switch control signal;
- a first capacitor configured to provide a first output voltage by storing an energy of the inductor;
- a second capacitor configured to provide a second output voltage by storing the energy of the inductor;
- a third capacitor configured to provide a third output voltage by storing the energy of the inductor;
- a first switch configured to control a signal transmission path between the inductor and the first capacitor according to a first control signal;
- a second switch configured to control a signal transmission path between the inductor and the second capacitor according to a second control signal;
- a third switch configured to control a signal transmission path between the inductor and the third capacitor according to a third control signal;
- a first feedback circuit configured to provide a first feedback voltage corresponding to the first output voltage;
- a second feedback circuit configured to provide a second feedback voltage corresponding to the second output voltage;
- a third feedback circuit configured to provide a third feedback voltage corresponding to the third output voltage;
- and
- a boost control circuit configured to generate the switch control signal according to the first feedback signal, generate the first control signal according to the first feedback signal and the switch control signal, generate the second control signal according to the first feedback signal, the second feedback signal and the first control signal, and generate the third control signal according to the first feedback signal, the third feedback signal and the second control signal.
A driving method for operating a backlight module, comprising:
- an energy-storing device receiving an input voltage for storing a corresponding energy;
- providing a first output voltage, a second output voltage and a third output voltage by receiving the energy stored in the energy-storing device;
- controlling a signal transmission path between the input voltage and the energy-storing device according to a first feedback voltage, wherein the first feedback voltage is related to the first output voltage;
- controlling a signal transmission path between the energy-storing device and the first output voltage according to the first feedback voltage;
- controlling a signal transmission path between the energy-storing device and the second output voltage according to the first feedback voltage and a second feedback voltage, wherein the second feedback voltage is related to the second output voltage;
- and
- controlling a signal transmission path between the energy-storing device and the third output voltage according to the first feedback voltage and a third feedback voltage, wherein the third feedback voltage is related to the third output voltage.
Dependencies are inferred from the claim text.