CN110828440A - Packaged LED integrated with constant current control chip - Google Patents

Abstract

The invention discloses a packaged LED integrated with a constant current control chip, which comprises: the LED constant current control module comprises an LED light-emitting chip, a first metal support used for mounting the LED light-emitting chip, a constant current control chip and a second metal support used for mounting the constant current control chip, wherein the LED light-emitting chip, the constant current control chip, the first metal support and the second metal support are electrically connected through wires, and the LED light-emitting chip, the constant current control chip, the first metal support, the second metal support and the wires are packaged through colloids; the first metal support and the second metal support are at least partially exposed out of the colloid to form an electrode of the packaged LED. Compared with the common LED product, the LED lamp does not need any other element outside, is simple and convenient to use, and can not cause the problem of brightness difference of the product due to inconsistent conduction voltage (VF value) of each LED light-emitting chip and the problem of brightness change due to power supply voltage change. The invention has the advantages of good brightness consistency, high reliability, more parallel lamp beads, longer product length and the like when being used integrally.

Description

A packaged LED with integrated constant current control chip

Technical field:

The invention relates to the technical field of LED lamps, in particular to a packaged LED integrated with a constant current control chip.

Background technique:

As shown in Figure 1, the current LED light string products on the market are completed by multiple ordinary LEDs connected in parallel to the electronic wire. Due to the resistance between the electronic wires, the longer the line between the electronic wire and the load, the longer the series resistance will be. Large, according to Ohm's law U=I*R, the greater the resistance, the greater the voltage drop. As shown in Figure 2, assuming that the line resistance generated by each segment is 0.01 ohms, and the current of each LED is 20mA, then the line resistance between the positive and negative of the first lamp is 0.02 ohms, then the voltage through the first lamp will generate 0.02* 20=0.4mV, the voltage drop after the second lamp is (0.02*2)*(20*2)=1.6mV, going down in order, the voltage drop after the 50th lamp is (0.02*50)*(20 *50)=1V, assuming that the power supply voltage is 5V, then the voltage shared by the 50th lamp is only 4V, then the brightness of the 50th lamp will definitely be darker than the first one. In this way, the brightness consistency of the LEDs will vary greatly. If the 100th lamp is connected in parallel later, the resulting voltage drop will make the LED brightness more and more obvious (see Figure 2). In addition, because the LED manufacturing process cannot guarantee the same VF value of each LED, under the condition that the voltage is relatively stable, the current flowing through each lamp may be inconsistent due to the difference in VF value. When the power supply voltage fluctuates and is unstable, the LED is easy to burn out due to excessive current. The reliability of the line is low.

In order to overcome the deficiencies existing in the existing products, the inventor of the present invention proposes the following technical solutions through continuous research and development.

Invention content:

The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a packaged LED with an integrated constant current control chip.

In order to solve the above technical problems, the present invention adopts the following technical scheme: a packaged LED integrating a constant current control chip, the packaged LED includes: an LED light-emitting chip, a first metal bracket for installing the LED light-emitting chip, a constant current control chip The chip and the second metal bracket for installing the constant current control chip, the LED light-emitting chip, the constant current control chip, the first metal bracket, and the second metal bracket are electrically connected by wires, and the above-mentioned LEDs are illuminated by colloid. The chip, the constant current control chip, the first metal support, the second metal support and the wire package; the first metal support and the second metal support are at least partially exposed outside the colloid and constitute the electrodes of the packaged LED.

Further, in the above technical solution, the wire includes: a first electrode wire used for connecting the first metal bracket and one electrode of the LED light-emitting chip; one of the other electrode of the LED light-emitting chip and the constant current control chip. The second electrode wire connected to the electrode; the third electrode wire used for connecting the other electrode of the constant current control chip to the second metal bracket.

Further, in the above technical solution, the part of the first metal bracket exposed outside the colloid constitutes the metal welding pin of the packaged LED, which is used to connect to the positive pole of the power supply, and the first electrode wire is connected to the first electrode wire. Between the metal bracket and the positive pole of the LED light-emitting chip; the part of the second metal bracket exposed outside the colloid constitutes the metal welding pin of the packaged LED, which is used to connect to the negative pole of the power supply, and the third wire is connected to the first Between the two metal brackets and the negative electrode of the constant current control chip; the second wire is connected between the negative electrode of the LED light-emitting chip and the positive electrode of the constant current control chip.

Further, in the above-mentioned technical solution, the constant current control chip includes: power consumption Q1 and Q4, conventional tubes Q2 and Q3, wherein the drain terminal of power consumption Q1 is connected to the input terminal VIN, and its gate terminal is connected to the source terminal; The gate terminal and the drain terminal of the conventional transistor Q2 are connected and connected to the source terminal of the drain Q1, and the source terminal of the conventional transistor Q2 is grounded; the drain Q1 and the conventional transistor Q2 work together to generate the internal reference voltage Vref; The gate of the conventional transistor Q3 is connected to Vref, the source terminal and the drain terminal are connected to ground; the gate of the consumption Q4 is connected to Vref, the source terminal is connected to ground, and the drain terminal is connected to the input terminal VIN.

After the present invention adopts the above technical solution, compared with ordinary LED products, the present invention does not need any other external components, and the use is simple and convenient. There will be no difference in brightness of the product due to the inconsistency of the on-voltage (VF value) of each LED light-emitting chip, and there will be no problem of brightness changes due to changes in the power supply voltage. In addition, in the same group of electronic wires, the packaged LEDs described in the present invention can be connected in parallel, and the product length can be made longer, without worrying about the inconsistent brightness of the lamp beads before and after the voltage drop of the wires during the transmission of the electronic wires. The product has the advantages of good brightness consistency, high reliability, large number of parallel lamp beads, and longer product length during overall use.

Description of drawings:

Figure 1 is a circuit structure diagram of a common LED light string on the market;

Figure 2 is a circuit diagram of the LED light string in Figure 1 after calculating the equivalent resistance of the circuit;

Fig. 3 is the three-dimensional structure schematic diagram of the present invention;

Fig. 4 is the front view of the present invention;

Fig. 5 is the side view of the present invention;

Fig. 6 is the circuit schematic diagram of LED constant current chip in the present invention;

7 is a simplified schematic diagram of the present invention after encapsulation;

FIG. 8 is a schematic diagram of a circuit of the present invention applied to a light string.

Detailed ways:

The present invention will be further described below with reference to specific embodiments and accompanying drawings.

The present invention discloses a packaged LED integrated with a constant current control chip. As shown in FIGS. 3 to 5 , the present invention includes: an LED light-emitting chip 1 , a first metal bracket 4 for mounting the LED light-emitting chip, and a constant current control chip 2 and a second metal bracket 3 for installing the constant current control chip 2, the LED light-emitting chip 1, the constant current control chip 2, the first metal bracket 4, and the second metal bracket 3 are electrically connected through wires, and are The colloid 8 encapsulates the above-mentioned LED light-emitting chip 1, the constant current control chip 2, the first metal bracket 4, the second metal bracket 3 and the wire; the first metal bracket 4 and the second metal bracket 3 are at least partially exposed in the colloid. 8, constitute the electrodes of the packaged LED.

Wherein, the wire includes: a first electrode wire 7 for connecting the first metal bracket 4 with one electrode of the LED light-emitting chip 1; for connecting the other electrode of the LED light-emitting chip 1 with one of the electrodes of the constant current control chip 2 The second electrode lead 5 ; the third electrode lead 6 for connecting the other electrode of the constant current control chip 2 to the second metal bracket 3 .

Specifically, the part of the first metal bracket 4 exposed outside the colloid 8 constitutes the metal welding pin of the packaged LED, which is used to connect to the positive pole of the power supply, and the first electrode lead 7 is connected to the first metal bracket 4 and the positive pole of the LED light-emitting chip 1;

The part of the second metal bracket 3 exposed outside the colloid 8 constitutes the metal welding pin of the packaged LED, which is used to connect to the negative pole of the power supply, and the third wire 6 is connected to the second metal bracket 3 and constant current control. Between the negative poles of chip 2;

The second wire 5 is connected between the negative electrode of the LED light-emitting chip 1 and the positive electrode of the constant current control chip 2 .

As shown in Fig. 6, this is the internal circuit schematic diagram of the constant current control chip 2, which includes: power consumption Q1 and Q4, conventional transistors Q2 and Q3, wherein the drain terminal of power consumption Q1 is connected to the input terminal VIN, and its gate The gate terminal and the source terminal are connected; the gate terminal and the drain terminal of the conventional transistor Q2 are connected and connected to the source terminal of the drain Q1, and the source terminal of the conventional transistor Q2 is grounded; the drain Q1 and the conventional transistor Q2 work together to generate The internal reference voltage Vref is connected; the gate of the conventional transistor Q3 is connected to Vref, the source terminal and the drain terminal are grounded; the gate of the consumption Q4 is connected to Vref, the source terminal is grounded, and the drain terminal is connected to the input terminal VIN.

As shown in Figure 6, the working principle of the constant current control chip 2 is: the internal reference voltage Vref is generated by the joint action of the two tubes Q1 and Q2. =0, a constant reference current Iref is generated. The G and D of the conventional tube Q2 (M2) are connected. Since the current is constant, its VGS (that is, Vref) is constant, and the temperature coefficient can be adjusted by adjusting the width-length ratio of the upper and lower tubes. The conventional transistor Q3 (M266) is a conventional transistor, the gate is connected to Vref, the source terminal and the drain terminal are grounded, and it is a low-pass filter capacitor of the reference voltage Vref to ground. Although the gate of Q4 (M272) is connected to Vref, the source terminal is grounded, and the drain terminal is connected to VIN; although Q4 is used as an output power control, the reference voltage Vref is fixed, regardless of the channel modulation effect, the output current is constant.

As shown in Figure 7, this is a simplified schematic diagram of the packaging circuit of the present invention. The LED light-emitting chip 1 and the constant current control chip 2 are connected in series, the positive electrode of the LED light-emitting chip 1 is connected to the positive electrode (+) of the external power supply, and the negative electrode of the LED light-emitting chip 1 is connected. It is connected with the input port (VIN) of the constant current control chip 2, and the negative electrode (GND) of the constant current control chip 2 is connected with the negative electrode (-) of the external power supply. The light-emitting chip and the constant current control chip in the packaged LED are packaged into a complete integrated electronic component. The current of the LED light-emitting chip is controlled by the constant current control chip. In the case of fluctuations or changes in the external power supply voltage, the application product can be guaranteed. The current flowing through each LED light-emitting chip is consistent, and the brightness is consistent, and the internal constant current control chip can also perform overcurrent protection and overheat protection for the LED light-emitting chip to improve the stability of the LED lamp beads.

As shown in Figure 8, this is to connect all the single-package LEDs shown in Figure 7 in parallel with the electronic wire (such as a light string product), and after powering it, the LED light-emitting chip inside each new LED can be controlled by constant current. The chip constantly controls the current flowing through it to ensure the same brightness of all new LEDs before and after. And when the number of parallel points is more, and the tail voltage drops slowly, the new LED can ensure that the current of the internal LED light-emitting chip is consistent. At the same time, the constant current control chip has built-in overheating and overcurrent protection circuit to prevent overcurrent and overheating damage to the light-emitting chip.

Of course, the above descriptions are only specific embodiments of the present invention, and are not intended to limit the scope of implementation of the present invention. All equivalent changes or modifications made according to the structures, features and principles described in the scope of the patent application of the present invention shall be included in the within the scope of the patent application of the present invention.

Claims (4)

1. A packaged LED integrated with a constant current control chip, comprising: the packaged LED includes: the LED constant current control module comprises an LED light-emitting chip (1), a first metal support (4) for mounting the LED light-emitting chip, a constant current control chip (2) and a second metal support (3) for mounting the constant current control chip (2), wherein the LED light-emitting chip (1), the constant current control chip (2), the first metal support (4) and the second metal support (3) are electrically connected through a wire, and the LED light-emitting chip (1), the constant current control chip (2), the first metal support (4), the second metal support (3) and the wire are packaged through a colloid (8);

the first metal support (4) and the second metal support (3) are at least partially exposed out of the colloid (8) to form an electrode of the packaged LED.

2. The packaged LED integrated with a constant current control chip according to claim 1, wherein: the lead comprises: a first electrode lead (7) used for connecting the first metal bracket (4) with one electrode of the LED light-emitting chip (1); a second electrode lead (5) used for connecting the other electrode of the LED light-emitting chip (1) with one electrode of the constant current control chip (2); and a third electrode lead (6) used for connecting the other electrode of the constant current control chip (2) with the second metal bracket (3).

3. The packaged LED integrated with a constant current control chip according to claim 2, wherein: the part of the first metal support (4) exposed out of the colloid (8) forms a metal welding leg of the packaged LED and is used for being connected to the positive electrode of a power supply, and the first electrode lead (7) is connected between the first metal support (4) and the positive electrode of the LED light-emitting chip (1);

the part of the second metal support (3) exposed out of the colloid (8) forms a metal welding leg of the packaged LED and is used for being connected to the negative electrode of a power supply, and the third lead (6) is connected between the second metal support (3) and the negative electrode of the constant current control chip (2);

the second lead (5) is connected between the cathode of the LED light-emitting chip (1) and the anode of the constant current control chip (2).

4. The packaged LED integrated with a constant current control chip according to any one of claims 1 to 3, wherein: the constant current control chip (2) comprises: the consumption transistors Q1 and Q4 and the conventional transistors Q2 and Q3, wherein the drain terminal of the consumption transistor Q1 is connected with the input terminal VIN, and the gate terminal is connected with the source terminal; the grid end and the drain end of the conventional tube Q2 are connected and connected with the source end of the drain tube Q1, and the source end of the conventional tube Q2 is grounded; the depletion tube Q1 and the conventional tube Q2 work together to generate an internal reference voltage Vref;

the grid of the conventional tube Q3 is connected with Vref, and the source end and the drain end are grounded;

although the gate of the Q4 is connected to Vref, the source terminal is grounded, and the drain terminal is connected to the input terminal VIN.

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