Analysis of the advantages and disadvantages of 10 classic LED driven power chips

Due to the conduction characteristics of LED PN junction, the voltage and current range of the power supply is very narrow. A slight deviation may not be able to light LED or reduce the luminous efficiency seriously, or shorten the service life and even burn down the chip. The current power frequency power supply and the common battery power supply are not suitable for direct supply of LED, and the LED driver is an electronic component that drives LED to work in the best voltage or current state.

1, because LED is a characteristic sensitive semiconductor device and has the characteristic of negative temperature, the LED drive power supply (also called drive) is the protection of its stable working state during the application process.

2, the requirements of LED devices on driving power are almost harsh. Unlike ordinary incandescent bulbs, LED can directly connect 220V's AC power. LED is a low voltage driver. It is necessary to design complex conversion circuits. Different LED lamps should be equipped with different power adapters. The design of a good power supply must take into account efficiency conversion, effective power, constant current precision, power life, EMC, as the power is as important as the heart of a human heart.

LED drive price

Depending on its power, it usually ranges from more than 10 to 100 yuan. Of course, the cost is continuing to decline.

Analysis of several classic LED driver chips

It is appropriate for IC to design enterprises to understand what kind of IC the market needs and what price should be set. The price will be changed at any time only for the reference value. Quality and price are the factors to decide whether to adopt or not. It is very important to meet the requirements of product design quality parameters. Price is more important!

Now more and more IC designers have joined the LED design team to design many models, and discuss in detail in terms of performance and price ratio, how to choose their own IC, which IC is the most suitable for the product to be designed for.

1, LED driven IC-AMC7150 with mixed market

AMC7150 was good at that time. I think about it or Ti, it has a very important factor is the price, there is less than 2 yuan in the market price, it is your reason to adopt it. AMC7150 now has dozens of IC models that can be directly replaced, and price wars will be inevitable.

It can be selected in low voltage 4-25V products with low design parameters, and the basic driving capability is less than 3W. For example, 1W string 3 or 3W 1 LED design is stable.

2. Hangzhou microelectronic -SB42511

At present, the new IC launched by Shi LAN semiconductor is mainly aimed at driving the 24V driving 6 LED markets. The price is higher than AMC7153 preferential in European and American market IC, suitable for the design of 1-6 LED, input 6-25V input voltage, SOP8 packaging form, mainly for the current low-end light market.


This IC drives 1-7 1W LED. Efficiency can reach 92%, 6-28V voltage input range step-down drive application design. The biggest advantage over the previous two IC is the size of the SOT23 package, which is in line with the design requirements of most small volume lamp cups.

Large resistance range, current adjustment, potentiometer wide resistance range to adjust brightness, such as designing desk lamp and so on.

4, European Zetex company - ZXLD1350

The IC has a good market response. It is also a SOT23 small volume package with input 7-30V voltage and constant current drive 1-7psc LED. The circuit is simple and practical. In design, Rs should be close to IC to avoid the great supply of voltage, which will affect the constant current effect.

The overall cost of electronic materials is slightly higher than that in the preceding paragraph (IC).

5. National semiconductor LM3402

LM3402 market reflects well, the input voltage range covers the entire automotive application field, the built-in MOS tube can be 15 LED, 1-3 LED is a little more expensive, more than 5 when the cost performance is very good. At present, the customer engineers who come into contact with it are highly valued. They are widely accepted in the field and are concise and practical. They are among the most outstanding LED drivers in IC.

6. National semiconductor LM3404 of the United States

LM3404 and LM3402 lines, the difference is that the current can reach 1A, driving 1-15pcsLED cost-effective.

The IC specifications listed above are all built in MOS tubes. The built-in MOS tube can simplify the line design, reduce the overall cost and reduce the failure rate. Because of its current IC technology, cost and other reasons that exceed 1A or more, LED driver IC needs external MOS tube. In our daily product design, we often meet large current design, such as 5W, 10W and other higher power design requirements, that can only choose the external MOS tube IC can. Next, we will recommend several IC with comprehensive cost, which is convenient for the selection of engineers.

7, the United States credit integration products company MAX16819/MAX16820

MAX16819/MAX16820 works at 4. 5V to 28V input voltage range, and has a 5V/10m on chip regulator. The output current is regulated by the high side current detection resistor, and the dedicated PWM input (DIM) can achieve a wide range of pulse brightness adjustment.

MAX16819/MAX16820 is ideal for applications requiring wide input voltage range. High side current detection and built-in current setting circuit enable the smallest number of external components, and can provide + 5% accuracy of LED current. In the process of load switching and PWM brightness adjustment, the hysteresis control algorithm ensures excellent input power rejection and fast response. MAX16819 has 30% ripple current, while MAX16820 has 10% ripple current. These devices can operate at switching frequencies up to 2MHz, thus allowing the use of small components.

MAX16819/MAX16820 can operate at -40 degree C to +125 degree C automotive temperature range, which can provide 3mm x 3mm x 0. 8mm, 6 pin TDFN package.

Personal recommendation 200-500Hz PWM grayscale frequency adjustment, 1-6pcs LED serial connection the largest 25W product design, recommend about 0 of the price. About 5 dollars

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