Patent ID: 11916481
Assignee: FREMONT MICRO DEVICES CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 9:
10. An application circuit of a Buck constant voltage driver comprising a Buck constant voltage driver and a peripheral circuit;
wherein the Buck constant voltage driver comprises a power tube control module, an output voltage acquisition module, an output voltage control module, a power tube and a sampling resistor, and an output voltage compensation module, wherein the power tube and the sampling resistor are connected in series between a chip external power supply terminal and a chip ground, the output voltage acquisition module is operable to acquire an output voltage of the Buck constant voltage driver, the output voltage control module is operable to implement an error amplification on the output voltage acquired by the output voltage acquisition module and a preset first reference voltage and to enable the power tube control module to control a switch-on and switch-off of the power tube based on an error amplification result for maintaining the output voltage of the Buck constant voltage driver constant; wherein an input terminal of the output voltage compensation module is connected between the sampling resistor and the power tube to acquire a sampling voltage on the sampling resistor, an output end of the output voltage compensation module is connected with an input terminal of the output voltage control module, wherein the output voltage compensation module is operable to acquire an output current information based on the sampling voltage on the sampling resistor, and to compensate the preset first reference voltage according to the output current information, thus maintaining the output voltage of the Buck constant voltage driver constant, under different output current conditions;
wherein the peripheral circuit comprises a chip power supply diode, a freewheeling diode, an output resistor, an output capacitor, an input capacitor, an inductor and a power supply capacitor; wherein a first terminal of the inductor is connected with the chip ground, a second terminal of the inductor is connected with a negative pole of the chip power supply diode and further connected with a negative pole of an external power supply through the output resistor, wherein the output capacitor is connected in parallel with the output resistor, a positive pole of the chip power supply diode is connected with the chip internal power supply terminal, the power supply capacitor is connected between the chip internal power supply terminal and the chip ground, wherein a positive pole of the freewheeling diode is connected with the chip ground, a negative pole of the freewheeling diode is connected with the negative pole of the external power supply, the chip external power supply terminal is connected with a positive pole of the external power supply, and the input capacitor is connected between the positive pole and the negative pole of the external power supply.