CN203872386U - Led drive circuit - Google Patents
Led drive circuit Download PDFInfo
- Publication number
- CN203872386U CN203872386U CN201420096539.7U CN201420096539U CN203872386U CN 203872386 U CN203872386 U CN 203872386U CN 201420096539 U CN201420096539 U CN 201420096539U CN 203872386 U CN203872386 U CN 203872386U
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- China
- Prior art keywords
- output
- circuit
- led drive
- pin
- control circuit
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- 239000003990 capacitor Substances 0.000 claims description 19
- 230000004224 protection Effects 0.000 claims description 7
- 238000001514 detection method Methods 0.000 claims description 5
- 230000005669 field effect Effects 0.000 claims description 3
- 229910044991 metal oxide Inorganic materials 0.000 claims description 3
- 150000004706 metal oxides Chemical class 0.000 claims description 3
- 239000004065 semiconductor Substances 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 7
- 230000002459 sustained effect Effects 0.000 description 6
- 230000009897 systematic effect Effects 0.000 description 2
- 230000001427 coherent effect Effects 0.000 description 1
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- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The utility model discloses an LED drive circuit. The LED drive circuit comprises an alternating current power supply input rectification and electromagnetic interference filter circuit, a control circuit and a buck-mode switch circuit. The input end of the alternating current power supply input rectification and electromagnetic interference filter circuit is connected with an alternating current power supply, and the output end of the alternating current power supply input rectification and electromagnetic interference filter circuit is connected with the input end of the control circuit. The input end of the control circuit is connected with the output end of the alternating current power supply input rectification and electromagnetic interference filter circuit and the output end of the control circuit is connected with the input end of the buck-mode switch circuit. The input end of the buck-mode switch circuit is connected with the output end of the control circuit and the output end of the buck-mode switch circuit is connected with a load. The LED drive circuit has a buck structure, the amount of system components is less than the amount of components of an LED drive circuit in the prior art and the LED drive circuit has advantages of high current precision, high conversion efficiency and rapid starting.
Description
Technical field
The utility model relates to circuit field, relates more specifically to a kind of buck configuration Switching Power Supply LED drive circuit.
Background technology
Light-emitting diode (LED) technology reaches its maturity at present, and has the features such as luminous efficiency is high, long service life due to it, therefore on lighting field, replaces traditional incandescent lamp very urgent.But, at the low-power LED such as existing Lamp cup, bulb, fluorescent tube with in Switching Power Supply scheme, the shortcomings such as ubiquity current precision is low, conversion efficiency is low, complex circuit and protection imperfection.Understand the useful life that affect LED because current precision is low; conversion efficiency is low can strengthen caloric value; complex circuit can cause printed panel size large, and protection imperfection can affect entire system reliability, therefore needs a kind of novel LED drive circuit to solve the problems referred to above.
Utility model content
One or more problems in view of the above, the utility model provides a kind of novel LED drive circuit.
According to LED drive circuit of the present utility model, comprise AC power input rectifying and electromagnetic interference filter circuit, control circuit and adjusting and voltage-reduction switch circuit, wherein: the input of AC power input rectifying and electromagnetic interference filter circuit is connected with AC power, output is connected with the input of control circuit; The input of control circuit is connected with the output of AC power input rectifying and electromagnetic interference filter circuit, and output is connected with the input of adjusting and voltage-reduction switch circuit; And the input of adjusting and voltage-reduction switch circuit and the output of control circuit be connected, output is connected with load.
There is high current precision, high conversion efficiency, low systematic part quantity, buck configuration according to LED drive circuit of the present utility model.
Brief description of the drawings
Below in conjunction with accompanying drawing to understanding better the utility model in the description of embodiment of the present utility model, wherein:
Fig. 1 shows according to the circuit diagram of the LED drive circuit of an embodiment of the utility model;
Fig. 2 shows according to the circuit diagram of the LED drive circuit of another embodiment of the utility model;
Fig. 3 shows according to the circuit diagram of the LED drive circuit of the another embodiment of the utility model;
Fig. 4 shows according to the circuit diagram of the LED drive circuit of the another embodiment of the utility model.
Embodiment
Feature and the exemplary embodiment of the utility model various aspects will be described in detail below.Many details have been contained in description below, to provide complete understanding of the present utility model.But, it will be apparent to one skilled in the art that the utility model can implement some details in these details in the case of not needing.Below the description of embodiment is only used to by illustrating that example of the present utility model provides the clearer understanding of the utility model.The utility model is never limited to any concrete configuration proposing below, but under the prerequisite that does not depart from spirit of the present utility model, has covered any amendment, replacement and the improvement of coherent element or parts.
Develop based on buck configuration switching circuit according to LED drive circuit of the present utility model.Below in conjunction with Fig. 1 to Fig. 4, describe in detail according to LED drive circuit of the present utility model.
Fig. 1 and 2 shows according to the circuit diagram of the LED drive circuit of the utility model embodiment.As illustrated in fig. 1 and 2, this LED drive circuit comprises: AC power (AC) input rectifying and electromagnetic interference (EMI) filter circuit 1, control circuit 2 and adjusting and voltage-reduction switch circuit 3.
Wherein, the input of AC input rectifying and EMI filter circuit 1 is connected with AC power, and output is connected with the input of control circuit 2; The input of control circuit 2 is connected with the output of AC input rectifying and EMI filter circuit 1, and output is connected with the input of adjusting and voltage-reduction switch circuit 3; And the input of adjusting and voltage-reduction switch circuit 3 is connected with the output of control circuit 2, output is connected with load.
By above-mentioned LED drive circuit, can overcome the problems such as caloric value short, that cause because conversion efficiency is low in LED useful life printed panel size large, that cause due to complex circuit that LED of the prior art causes because current precision is low is large.
As illustrated in fig. 1 and 2, AC input rectifying and EMI filter circuit 1 comprise: fuse F1, rectifier diode D1, D2, D3, D4, filter inductance L1, and filter capacitor C1, C2.
Control circuit 2 comprises pulse-width modulation (PWM) chip U1, and this chip comprises 5 function pin altogether, respectively:
The drain electrode pin (D pin) of interior metal oxide semiconductor field effect transistor (MOSFET): this drain electrode pin is connected with the output of EMI filter circuit with AC input rectifying;
Current detecting input pin (CS pin): for detection of functions such as voltage signal, shutoff and protections, this CS pin is connected with the input of adjusting and voltage-reduction switch circuit;
System overvoltage protection (OVP) detects pin (OVP pin): this OVP pin detects output voltage by resistance R 2 after flowing out electric current, when OVP pin voltage is less than after the threshold value of a setting, or flow out electric current and be greater than after the threshold value of a setting, close output, IC protection is provided; Although only have a resistance R 2 in diagram, can be multiple resistance serial or parallel connections in some applications.
Grounding leg (GND pin): with benchmark be connected, as the benchmark ground of PWM chip;
Chip power supply pin (VDD pin): be used to chip internal circuit supply, and by capacitor C 3 and benchmark be connected.
In the embodiment shown in Figure 2, VDD pin is also connected with the output of EMI filter circuit with AC input rectifying with R5 by resistance R 4.Particularly, VDD pin is connected with one end of starting resistance R5, one end of the other end contact resistance R4 of resistance R 5, and the other end of resistance R 4 is connected with the filter capacitor C2 positive pole in EMI filter circuit 1 with AC input rectifying.In other words, in the embodiment shown in Figure 2, control circuit 2 also comprises at least one resistance being connected between chip power supply pin (VDD pin) and AC power (AC) input rectifying and the output of electromagnetic interference (EMI) filter circuit 1.
Adjusting and voltage-reduction switch circuit 3 comprises that filter capacitor C4, step-down switching inductance L 2, sustained diode 5, CS pin detect resistance R 1 and output dummy load R3, are wherein connected in parallel between filter capacitor C4, output dummy load R3 and load; One end of step-down switching inductance L 2 is connected with the output (specifically the OVP pin of PWM chip is for detection of the resistance of output voltage) of filter capacitor C4, output dummy load R3, load and control circuit 2 respectively, and other end ground connection is also connected with the positive pole of sustained diode 5; The plus earth of sustained diode 5 is also connected with one end of buck inductor L2, and negative pole detects resistance R 1 with the output of control circuit 2 with CS pin respectively and is connected; One end that CS pin detects resistance R 1 is connected with the negative pole of sustained diode 5 with the output of control circuit 2 respectively, and other end ground connection is also connected with filter capacitor C4, output dummy load R3, load respectively.
Fig. 3 and 4 shows according to the circuit diagram of the LED drive circuit of other embodiment of the utility model, wherein Fig. 3 and Fig. 1 are basic identical, and Fig. 4 and Fig. 2 are basic identical, difference is only in the adjusting and voltage-reduction switch circuit 3 shown in Fig. 3 and 4, the plus earth of sustained diode 5 is also connected with one end of buck inductor L2, and minus earth is also connected with current detecting input pin detection resistance R 1, filter capacitor C4, output dummy load R3, load respectively; One end that CS pin detects resistance R 1 is only connected with the output of control circuit 2, and other end ground connection is also connected with negative pole, filter capacitor C4, output dummy load R3, the load of sustained diode 5 respectively.
The LED drive circuit providing according to the utility model, for example there is buck configuration, systematic part quantity, than the number of spare parts of LED drive circuit of the prior art few (not needing absorbing circuit), and there is high current precision, high conversion efficiency, startup fast.
Below with reference to specific embodiment of the utility model, the utility model has been described, but those skilled in the art all understand, can carry out various amendments, combination and change to these specific embodiments, and can not depart from the spirit and scope of the present utility model that limited by claims or its equivalent.In addition, it is only exemplary that any signal arrows in accompanying drawing should be considered to, instead of restrictive, unless separately there is concrete instruction.Make to separate or the ability of combination while not knowing when term is also contemplated as, the combination of assembly or step also will be considered to record.
Claims (9)
1. a LED drive circuit, comprises AC power input rectifying and electromagnetic interference filter circuit, control circuit and adjusting and voltage-reduction switch circuit, wherein:
The input of AC power input rectifying and electromagnetic interference filter circuit is connected with AC power, and output is connected with the input of control circuit;
The input of control circuit is connected with the output of AC power input rectifying and electromagnetic interference filter circuit, and output is connected with the input of adjusting and voltage-reduction switch circuit; And
The input of adjusting and voltage-reduction switch circuit is connected with the output of control circuit, and output is connected with load.
2. LED drive circuit according to claim 1, is characterized in that, described control circuit comprises pulse width modulating chip, and described pulse width modulating chip comprises following function pin:
The drain electrode pin of interior metal oxide semiconductor field effect transistor;
Current detecting input pin;
System overvoltage protection detects pin;
Grounding leg, with benchmark be connected; With
Chip power supply pin.
3. LED drive circuit according to claim 2, is characterized in that,
The drain electrode pin of described interior metal oxide semiconductor field effect transistor is connected with the output of described AC power input rectifying and electromagnetic interference filter circuit;
Described current detecting input pin is connected with the input of described adjusting and voltage-reduction switch circuit;
Described chip power supply pin by electric capacity and benchmark be connected.
4. LED drive circuit according to claim 2, described system overvoltage protection detects after pin flows out electric current and passes through resistance detection output voltage.
5. LED drive circuit according to claim 4, described resistance is a resistance, or the serial or parallel connection of multiple resistance.
6. LED drive circuit according to claim 3, is characterized in that, described control circuit also comprises at least one resistance being connected between described chip power supply pin and AC power input rectifying and the output of electromagnetic interference filter circuit.
7. according to the LED drive circuit described in any one in claim 1 to 5, it is characterized in that, described AC power input rectifying and electromagnetic interference filter circuit comprise fuse, rectifier diode, filter inductance and filter capacitor.
8. according to the LED drive circuit described in any one in claim 1 to 5, it is characterized in that, described adjusting and voltage-reduction switch circuit comprises that filter capacitor, step-down switching inductance, fly-wheel diode, current detecting input pin detect resistance and output dummy load, wherein
Between described filter capacitor, output dummy load and load, be connected in parallel;
One end of described buck inductor is connected with the output of described filter capacitor, output dummy load, described load and described control circuit respectively, and other end ground connection is also connected with the positive pole of fly-wheel diode;
The plus earth of described fly-wheel diode is also connected with one end of described buck inductor, and negative pole detects resistance with the output of described control circuit with current detecting input pin respectively and is connected;
One end that described current detecting input pin detects resistance is connected with the output of described control circuit and the negative pole of fly-wheel diode respectively, and other end ground connection is also connected with described filter capacitor, output dummy load, described load respectively.
9. according to the LED drive circuit described in any one in claim 1 to 5, it is characterized in that, described adjusting and voltage-reduction switch circuit comprises that filter capacitor, step-down switching inductance, fly-wheel diode, current detecting input pin detect resistance and output dummy load, wherein
Between described filter capacitor, output dummy load and load, be connected in parallel;
One end of described buck inductor is connected with the output of described filter capacitor, output dummy load, described load and described control circuit respectively, and other end ground connection is also connected with the positive pole of fly-wheel diode;
The plus earth of described fly-wheel diode is also connected with one end of described buck inductor, and minus earth is also connected with current detecting input pin detection resistance, described filter capacitor, output dummy load, described load respectively;
Described current detecting input pin detects one end of resistance and the output of described control circuit is connected, and other end ground connection is also connected with the negative pole of fly-wheel diode, described filter capacitor, output dummy load, described load respectively.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420096539.7U CN203872386U (en) | 2014-03-04 | 2014-03-04 | Led drive circuit |
| TW103205303U TWM485511U (en) | 2014-03-04 | 2014-03-27 | LED driver circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420096539.7U CN203872386U (en) | 2014-03-04 | 2014-03-04 | Led drive circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203872386U true CN203872386U (en) | 2014-10-08 |
Family
ID=51653303
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420096539.7U Expired - Lifetime CN203872386U (en) | 2014-03-04 | 2014-03-04 | Led drive circuit |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN203872386U (en) |
| TW (1) | TWM485511U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018184888A1 (en) * | 2017-04-05 | 2018-10-11 | Philips Lighting Holding B.V. | Led lighting driver and drive method |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104661410B (en) * | 2015-02-17 | 2017-09-19 | 昂宝电子（上海）有限公司 | LED drive system and LED driving methods |
-
2014
- 2014-03-04 CN CN201420096539.7U patent/CN203872386U/en not_active Expired - Lifetime
- 2014-03-27 TW TW103205303U patent/TWM485511U/en not_active IP Right Cessation
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018184888A1 (en) * | 2017-04-05 | 2018-10-11 | Philips Lighting Holding B.V. | Led lighting driver and drive method |
| CN110506451A (en) * | 2017-04-05 | 2019-11-26 | 昕诺飞控股有限公司 | LED illumination driver and driving method |
| US11083057B2 (en) | 2017-04-05 | 2021-08-03 | Signify Holding B.V. | LED lighting driver and drive method |
| CN110506451B (en) * | 2017-04-05 | 2022-08-26 | 昕诺飞控股有限公司 | LED lighting driver and driving method |
Also Published As
| Publication number | Publication date |
|---|---|
| TWM485511U (en) | 2014-09-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20141008 |