CN-122026723-A - Upper tube control circuit, LED driving circuit and LED driving power supply

CN122026723ACN 122026723 ACN122026723 ACN 122026723ACN-122026723-A

Abstract

The application provides an upper tube control circuit, an LED driving circuit and an LED driving power supply. The circuit comprises a control module, a switch module and a regulation and control module, wherein the switch module is respectively and electrically connected with the control module and the regulation and control module, the switch module is used for being electrically connected with the grid electrode of the upper tube in the LED driving circuit, and the regulation and control module is used for being respectively and electrically connected with the drain electrode of the lower tube and the source electrode of the upper tube in the LED driving circuit. When the input voltage of the LED driving circuit is larger than or equal to a first preset value or the node voltage is larger than or equal to a second preset value, the control module is used for outputting a first control signal to the switch module, the switch module is used for being conducted according to the first control signal, the grid electrode of the upper tube is connected with the regulation module, the regulation module is used for regulating the grid voltage of the upper tube to enable the upper tube to be half-opened, and the node voltage is the voltage of the LED driving tube in the LED driving circuit and the common end of the LED in the LED driving circuit.

Inventors

LIN DASONG
Lan chuang
CHEN TIANZHI

Assignees

深圳市微源半导体股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. The upper tube control circuit is characterized by comprising a control module, a switch module and a regulation module, wherein the switch module is respectively and electrically connected with the control module and the regulation module, the switch module is used for being electrically connected with a grid electrode of an upper tube in the LED drive circuit, and the regulation module is used for being respectively and electrically connected with a drain electrode of a lower tube in the LED drive circuit and a source electrode of the upper tube; When the input voltage of the LED driving circuit is larger than or equal to a first preset value and the node voltage is larger than or equal to a second preset value, the control module is used for outputting a first control signal to the switch module, the switch module is used for being conducted according to the first control signal, the grid electrode of the upper tube is connected with the regulation module, the regulation module is used for regulating the grid voltage of the upper tube to enable the upper tube to be half-opened, and the node voltage is the voltage of the LED driving tube in the LED driving circuit and the common end of the LED in the LED driving circuit.
2. The upper tube control circuit according to claim 1, wherein when the input voltage of the LED driving circuit is smaller than the first preset value or the node voltage is smaller than the second preset value, the control module is further configured to output a second control signal to the switch module, and the switch module is configured to disconnect the gate of the upper tube from the regulation module according to the second control signal.
3. The upper tube control circuit of claim 1, wherein the control module comprises a first comparison unit, a second comparison unit, and a logic unit, the logic unit being electrically connected to the first comparison unit, the second comparison unit, and the switch module, respectively, the first comparison unit being configured to receive the input voltage, the second comparison unit being configured to receive the node voltage; The first comparison unit is used for comparing the input voltage with the first preset value and outputting a first comparison signal when the input voltage is greater than or equal to the first preset value, the second comparison unit is used for comparing the node voltage with the second preset value and outputting a second comparison signal when the node voltage is greater than or equal to the second preset value, and the logic unit is used for outputting the first control signal according to the first comparison signal and the second comparison signal.
4. A top pipe control circuit according to claim 3, wherein the first comparator comprises a first comparator, a first input terminal of the first comparator is configured to receive the input voltage, a second input terminal of the first comparator is configured to receive the first preset value, and an output terminal of the first comparator is electrically connected to the logic unit.
5. A top pipe control circuit according to claim 3, wherein the second comparing unit comprises a second comparator, a first input terminal of the second comparator is configured to receive the node voltage, a second input terminal of the second comparator is configured to receive the second preset value, and an output terminal of the second comparator is electrically connected to the logic unit.
6. A header control circuit according to claim 3, wherein the logic unit comprises an and gate, a first input of the and gate is electrically connected to the first comparison unit, a second input of the and gate is electrically connected to the second comparison unit, and an output of the and gate is electrically connected to the switch module.
7. The upper tube control circuit of claim 1, wherein the switch module comprises a first switch, a control end of the first switch is electrically connected with the control module, a first end of the first switch is electrically connected with the gate of the upper tube, and a second end of the first switch is electrically connected with the regulation module.
8. The upper tube control circuit of any one of claims 1-7, wherein the regulation module comprises a first power tube and a first current source, a gate of the first power tube is electrically connected to a drain of the first power tube, a first end of the first current source, and the switch module, a source of the first power tube is electrically connected to a source of the upper tube and a drain of the lower tube, respectively, and a second end of the first current source is grounded.
9. An LED driving circuit is characterized by comprising an upper tube, a lower tube, an input inductor, an LED driving tube, an LED and the upper tube control circuit according to any one of claims 1-8, wherein a grid electrode of the upper tube is electrically connected with a switch module in the upper tube control circuit, a source electrode of the upper tube is electrically connected with a first end of the input inductor, a drain electrode of the lower tube and a regulating module in the upper tube control circuit respectively, a second end of the input inductor is used for receiving input voltage, the source electrode of the lower tube is grounded, if the LED driving tube is an NMOS tube, the drain electrode of the upper tube is electrically connected with an anode of the LED, the drain electrode of the LED driving tube is electrically connected with a cathode of the LED, the source electrode of the LED driving tube is grounded, and if the LED driving tube is a PMOS tube, the drain electrode of the upper tube is electrically connected with the source electrode of the LED driving tube, the anode of the LED is electrically connected with the drain electrode of the LED driving tube, and the cathode of the LED is grounded.
10. An LED driving power supply comprising the LED driving circuit of claim 9.

Description

Upper tube control circuit, LED driving circuit and LED driving power supply Technical Field The application belongs to the technical field of power supplies, and particularly relates to an upper tube control circuit, an LED driving circuit and an LED driving power supply. Background In the power field, an LED driving circuit based on a boost DCDC architecture is widely applied to the fields of vehicle-mounted and industrial illumination and the like due to wide input voltage scene adaptation, and mainly comprises a high-side upper tube, a low-side lower tube, an input inductor, an LED driving tube and an LED load. When the framework works, the LED driving tube is in a boosting mode under low input voltage, the voltage of the LED driving tube is reduced, the power consumption is controllable, the boost DCDC stops the switch work under high input voltage, the upper tube enters a full-open bypass state, the voltage difference between the input voltage and the forward voltage drop of the LED is almost completely borne by the LED driving tube, the power consumption of the LED driving tube is greatly increased, and the reliability of the driving circuit is greatly reduced. Disclosure of Invention The embodiment of the application provides an upper tube control circuit, an LED driving circuit and an LED driving power supply, which can solve the problems that the power consumption of an LED driving tube is greatly increased and the reliability of the driving circuit is greatly reduced under the condition of high input voltage. In a first aspect, an embodiment of the present application provides an upper tube control circuit, which is applied to an LED driving circuit, where the upper tube control circuit includes a control module, a switch module and a regulation module, the switch module is electrically connected with the control module and the regulation module, the switch module is electrically connected with a gate of an upper tube in the LED driving circuit, and the regulation module is electrically connected with a drain of a lower tube and a source of the upper tube in the LED driving circuit; When the input voltage of the LED driving circuit is larger than or equal to a first preset value and the node voltage is larger than or equal to a second preset value, the control module is used for outputting a first control signal to the switch module, the switch module is used for being conducted according to the first control signal, the grid electrode of the upper tube is connected with the regulation module, the regulation module is used for regulating the grid voltage of the upper tube to enable the upper tube to be half-opened, and the node voltage is the voltage of the LED driving tube in the LED driving circuit and the common end of the LED in the LED driving circuit. In a possible implementation manner of the first aspect, when the input voltage of the LED driving circuit is smaller than the first preset value or the node voltage is smaller than the second preset value, the control module is further configured to output a second control signal to the switch module, and the switch module is configured to disconnect the gate of the upper tube from the regulation module according to the second control signal. In a possible implementation manner of the first aspect, the control module includes a first comparing unit, a second comparing unit, and a logic unit, where the logic unit is electrically connected to the first comparing unit, the second comparing unit, and the switching module, respectively, and the first comparing unit is configured to receive the input voltage, and the second comparing unit is configured to receive the node voltage; The first comparison unit is used for comparing the input voltage with the first preset value and outputting a first comparison signal when the input voltage is greater than or equal to the first preset value, the second comparison unit is used for comparing the node voltage with the second preset value and outputting a second comparison signal when the node voltage is greater than or equal to the second preset value, and the logic unit is used for outputting the first control signal according to the first comparison signal and the second comparison signal. In a possible implementation manner of the first aspect, the first comparing unit includes a first comparator, a first input terminal of the first comparator is configured to receive the input voltage, a second input terminal of the first comparator is configured to receive the first preset value, and an output terminal of the first comparator is electrically connected to the logic unit. In a possible implementation manner of the first aspect, the second comparing unit includes a second comparator, a first input terminal of the second comparator is configured to receive the node voltage, a second input terminal of the second comparator is configured to receive the second preset value, and an output terminal of the seco