TWM393951U - Switching LED driver - Google Patents

Description

M393951 V. New description: [New technical field] [0001] This creation relates to a light-emitting diode driving device, in particular to a light-emitting diode driving device with a shunting mechanism. [Prior Art]

[0002] A Light Emitting Diode (LED) is a current-driven low-voltage unidirectional conductive element, and the luminous flux of the light-emitting diode itself is related to the current flowing through the light-emitting diode. The change, thus providing a stable current source to the string or array of light emitting diodes, is effective to achieve uniform brightness. [0003] At present, the squeezing circuit for driving the LED string is packaged into an integrated circuit (1C) 1 and the driving 1C is set to have a controllable current when the package is formed (contro 11 able current) ). When the number of light-emitting diodes used in the light-emitting diode string is increased, the current flowing through the light-emitting diode string tends to increase in order to achieve an increase in the luminance of the light-emitting diode string.

[0004] However, when the driving current required for the LED string is greater than the controllable current of the control driver 1C, the temperature of the control driver 1C itself is increased, thereby making the control drive 1C as a whole. The service life is reduced. Therefore, how to control the driving and driving of the LED string can be achieved without changing the driving current of the LED string, which has become a major problem for manufacturers in this field. [New Content] [0005] In view of the prior art, one of the purposes of the present invention is to provide a M393951 optical diode driving device with a single number A0101, a third page, and a total of 13 pages, which is driven by the LED driving device. A light-emitting diode lamp set, wherein the light-emitting diode lamp set is turned on to have an on-current. The LED driving device comprises a control driving unit and a current regulating unit. [0006] the control driving unit, the control driving unit has a controllable current; [0007] the current regulating unit is electrically connected to the light emitting diode lamp group, and the current regulating unit divides the conducting current into two The branch circuit controls the amount of current of one of the branches to be proportional to the controllable current amount of the control driving unit, and conducts the controllable current to the control driving unit for supplying a steady current to the control driving unit. . . . [0008] The present invention divides the on-current into one for the control driving unit through an external current regulating unit between the LED lamp set and the control driving unit. The current is used in proportion to the current of the tunable current and the control drive unit to effectively prevent the control drive unit from being damaged by excessive current. [Embodiment] [0009] Referring to the first figure, a circuit block diagram of the light-emitting diode driving device of the present invention is shown. The LED driving device is configured to drive a light emitting diode unit 10, and the LED driving device comprises a control driving unit 20 and a current adjusting unit 30. [0010] The light-emitting diode lamp set 10 includes a plurality of light-emitting diodes 100, which are connected in series by a positive electrode to a negative electrode, so that currents passing through the light-emitting diodes 100 are equal, and assuming conduction The current of the LED lamp set is an on current IT pn.

LED Form No. A0101 Page 4 of 13 M393951 [0011] The control driving unit 20 is electrically connected to the LED group 10 for driving the LEDs 100 and controlling the LEDs 100 shades of light. The control driving unit 20 is a packaged integrated circuit and has a controllable current Ie. [0012] The current adjustment unit 30 is electrically connected to the LED group 10 for distinguishing the conduction current I, π passing through the LED 100 into two different

The branches of the LEDs are the first branch and the second branch, respectively. In this embodiment, the first branch is electrically connected to the control driving unit 20, the second branch is connected to the ground, and the first branch is turned on to have a first current II, and the second branch has a first branch The second current is 12. In addition, the LED driving system further includes a controller 40 electrically connected to the current regulating unit 30. The controller 40 is mainly configured to control the amount of current of the first current II that is turned on to the control driving unit 20, so that the current amount of the first current 11 is proportional to the controllable current Ip of the control driving unit 20, that is, Il. = nxL, where η is a constant, such that L t prevents the control drive unit 20 from being damaged by excessive current. In addition, the current value of the second current 12 flowing through the second branch is equal to the current value of the adjustable current control I I of the LED unit minus the adjustable LLC control current I ^ of the control driving unit 20, that is, 12 = I, ϋη _ 11.

C LED

[0014] Furthermore, the first current II and the second current 12 are multiplied by the controller, that is, I=NxI2, where N is a constant. [0015] Referring to the second figure, a circuit diagram of the light-emitting diode driving device of the first embodiment is created. In this embodiment, the current regulating unit is a current mirror composed of a pair of PNP bipolar junction transistors (Bipolar Junction Tran-form No. A0101, page 5/13 M393951 sistor, BJT). The current adjustment unit includes a first transistor Q1 and a second transistor Q2. The first transistor Q1 is connected to the base of the second transistor Q2, the base of the first transistor Q1 is connected to the collector, and the collector of the first transistor Q1 is electrically connected to the control driver. Unit 20, the collector of the second transistor Q2 is connected to the ground. In addition, the first transistor Q1 and the emitter of the second transistor Q2 are respectively connected in series with a first resistor R1 and a second resistor R2. [0016] In actual operation, the conduction current flowing through the light-emitting diode lamp set is 1,

The LED flows through the current mirror and is divided into a first branch and a second branch, wherein the first path corresponds to the first transistor Q1, and the second branch corresponds to the second transistor Q2. The first transistor Q1 is an input end of the current mirror, so that the on current IT of the light emitting diode outputs a current amount of a first current 11 flowing through the first branch, wherein the first current II is equal to The controllable current Ie is controlled in proportion to the control drive unit 20, and the first current is supplied to the control drive unit 20. Since the current regulating unit 30 is a current mirror, the current value flowing through the second branch is 12 = ΝχΙ 1, where N is a constant ' and 11 + 12 = 1.

led

[0017] Referring to the third figure, a circuit diagram of the light-emitting diode control driving shunt device of the second embodiment of the present invention is shown. The current regulating unit 30 includes a sampling resistor 310, a comparator 320, a switching element 330, an operational amplifier 340, and a setting resistor 350. The sampling resistor 310 is electrically connected between the LED sub-group 10 and the control driving unit 20. The two pins of the comparator 320 are respectively connected to the sampling resistor 310 for obtaining a sampling voltage. The switching element 330 is electrically connected to the LED group 10 and connected to the ground via the setting resistor 350. The operation form No. A0101, page 6 of 13 M393951, the output of the amplifier 340 is electrically connected to the The gate of the switching element 330, the forward input of the operational amplifier 340 is electrically coupled to the output of the comparator 320, and the inverting input of the operational amplifier 340 is electrically coupled to the set resistor 350. [0018] The turn-on voltage IIIin of the light-emitting diode lamp set 10 is divided into a first branch that is conducted to the control driving unit 20 via the sampling resistor, and a second branch that flows through the switching element 330. And the first branch and the second branch respectively conduct a first current 11 and a second current I 2 . [0019] When the first current II flows through the sampling resistor 310, a voltage drop is generated on the sampling resistor 310, and the output of the comparator 320 takes a sampling voltage, and the sampling voltage value is obtained. Output to the forward input of the operational amplifier 340. The second current 12 流 flows through the set resistor 350 via the switching element 330, generates a set voltage drop across the set resistor 350, and inputs the set voltage drop to the inverting input of the operational amplifier 340. The operational amplifier 340 can effectively adjust the current value of the first current II to be proportional to the controllable current L of the control driving unit 20, and the current value of the second current is I-I I. [0020] In summary, the LED driving device of the present invention is electrically connected between the LED lamp set and the control driving unit by an external current adjusting unit, so that the user can provide a suitable Driving current of the LED group to drive the LED group to a preferred brightness; and effectively adjusting the driving current to two parts through the current adjusting unit, and making one of the parts The current is proportional to the controllable current of the control drive unit and is used by the control drive unit to prevent the control drive unit from being damaged by excessive current. Form No. A0101 Page 7 of 13 M393951 [0021] However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention cannot be limited, that is, the equivalent of the patent application scope of the present invention. Changes and modifications, etc., shall remain within the scope of the intent of the patent coverage of this creation. [Brief Description] [0022] The first figure is a circuit block diagram of the LED driving device of the present invention. [0023] The second figure is a circuit diagram of the light-emitting diode driving device of the first embodiment. [0024] The third figure is a circuit diagram of the light-emitting diode driving device of the second embodiment of the present invention. [Description of main component symbols] [0025] 10 LEDs [0026] 100 LEDs [0027] 20 Control Drive Unit [0028] 30 Current Regulation Unit [0029] 310 Sampling Resistors [0030] 320 Compare [0031] 330 Switching Element [0032] 340 Operational Amplifier [0033] 350 Setting Resistor [0034] 40 Controller Form No. A0101 Page 8 of 13 M393951 [0035] 11 First Current [0036] 12 Second Current [0037] Adjustable Current [0038] \ED On Current Form No. A0101 Page 9 of 13

Claims (1)

M393951 VI. Patent application scope: 1. A light-emitting diode driving device for driving a light-emitting diode lamp group, wherein the light-emitting diode lamp group is turned on to have a conducting current, and the light-emitting diode driving system comprises: a control driving unit having a controllable current; a current regulating unit electrically connected to the light emitting diode lamp group, the current regulating unit dividing the conduction current into two branches and controlling one of the branches The t flow rate is proportional to the controllable current amount of the control drive unit, and then the controllable current is conducted to the control drive unit for supplying a steady current to the control drive unit. The illuminating diode driving device of claim 1, wherein the current regulating unit comprises: a first transistor and a second transistor, the base and the collector of the first transistor Connected, the first transistor is connected to the base of the second transistor, and the collector of the first transistor is electrically connected to the control driving unit, and the collector of the second transistor is connected to the ground. 3. The LED driving device of claim 2, further comprising two resistors electrically connected to the first transistor and the emitter of the second transistor, respectively. 4. The LED driving device of claim 2, wherein the first transistor and the second transistor are both bipolar junction transistors. 5. The illuminating diode driving device of claim 1, wherein the current regulating unit comprises: a sampling resistor electrically connected between the illuminating diode lamp set and the control driving unit; 099214357 Form No. A0101 Page 10 of 13 0992043681-0 M393951 A comparator, the input end of the comparator is connected across the sampling resistor; a switching element electrically connected to the LED lamp set; a resistor electrically connected to the switching element; and an operational amplifier having a forward input terminal, a negative input terminal and an output terminal, the positive input terminal being electrically connected to the output end of the comparator, the negative direction The input terminal is electrically connected to the set resistor, and the output terminal is electrically connected to one of the gates of the switching element. 6. The illuminating diode driving device of claim 1, wherein the illuminating diode lamp set comprises a plurality of illuminating diodes, wherein the illuminating diodes are connected in series. 7. The LED driving device of claim 1, further comprising a controller electrically connected to the current regulating unit. 0992043681-0 099214357 Form No. A0101 Page 11 of 13