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

Due to the conduction characteristics of the LED PN junction, the range of voltage and current variations of the power supply it can adapt to is very narrow. A slight deviation may fail to light up the LED or reduce the luminous efficiency severely, or shorten the service life or even burn the chip.The current commercial frequency power supply and common battery power supply are not suitable for directly supplying LEDs. LED drivers are such electronic components that can drive LEDs to work in a priority voltage or current state.


1. Since LED is a sensitive semiconductor device and has negative temperature characteristics, LED driving power supply (also called driver) is to protect it in a stable working state during the application process.


2. The requirements of LED devices for driving power are almost harsh. Unlike ordinary incandescent light bulbs, LEDs can be directly connected to 220V AC mains.LED is a low-voltage driver. It is necessary to design a complex conversion circuit. Different LED lamps must be equipped with different power adapters.When designing a good power supply, factors such as efficiency conversion, effective power, constant current accuracy, power supply life, and electromagnetic compatibility must be considered, because the role of the power supply in the entire lamp is as important as the human heart.



LED driver price

Depending on its power, it is generally between 10 and 100 yuan.Of course, costs have continued to decrease.


Analysis of several classic LED driver chips

For IC design companies to understand what kind of IC is needed in the market and what price should be set.Prices may change at any time for reference only.Quality and price are the factors that determine whether to adopt, and it is important to meet the product design quality parameter requirements!Price matters!

Now more and more IC design manufacturers have joined the LED design team and designed many models. Here we will discuss in detail from the aspect of cost performance, how to choose the right IC, and which IC is suitable for the product that you are preparing to design.


1. Mixed LED market driver IC-AMC7150

At the time, the AMC7150 was good. I thought about it and mentioned that it has a very important factor is the price. There is a market price of less than 2 yuan.The AMC7150 currently has dozens of IC models that can be directly replaced, and the price war will be unavoidable.

It can be selected in low voltage 4-25V products with low design parameter requirements, and the basic drive capacity is designed for applications below 3W.For example, 1W string 3 or 3W 1 LED design is stable.



2.Hangzhou Shilan Microelectronics-SB42511

Currently Silan Semiconductor has launched a new IC, which is mainly aimed at driving 24 LEDs to drive 6 LED markets.The price is higher than AMC7153, which is preferential for ICs in European and American markets. It is suitable for designing 1-6 LEDs, inputting 6-25V input voltage, and SOP8 package form, mainly targeting the current low-end spotlight market.



3.American CATALYST company-CAT4201

This IC drives 1-7 1W LEDs.Efficiency up to 92%, 6-28V voltage input range step-down drive application design.The big advantage over the previous two ICs is the size of the package SOT23 and the circuit introduction, which meets the current requirements for the design and use of most small-sized lamp cups.

Large resistance range current adjustment, can adjust the brightness of the potentiometer wide resistance range, such as when designing products such as table lamps.


4.Europe Zetex—ZXLD1350

This IC is currently responding well in the market, and it is also a SOT23 small volume package. It inputs 7-30V voltage step-down constant current to drive 1-7psc LEDs, and the circuit is simple and practical.When designing, Rs should be close to the IC to prevent the power supply voltage from largely immoving, which will affect the constant current effect.

The overall cost of electronic materials is slightly higher than the previous IC.


5.National Semiconductor LM3402

The LM3402 has a good market response. The input voltage range covers the entire automotive application area. The built-in MOS tube can have 15 LEDs at most, and 1-3 LEDs feel a little expensive.At present, the customer engineers who have been contacted have high evaluations, and the acceptance field is relatively wide and the lines are simple and practical. It is the leader among many LED driver ICs in the country.



6.National Semiconductor LM3404

LM3404 and LM3402 have the same circuit, the difference is that the current can reach 1A, and it is more cost-effective to drive 1-15pcsLED.

The IC specifications listed above are all built-in MOS tubes. The built-in MOS tubes can simplify the circuit design, reduce the size, reduce the overall design cost, and reduce the failure rate.Due to its current IC process manufacturing, cost and other reasons, LED driver ICs greater than 1A require external MOS tubes.In our daily product design, high-current design is often encountered, such as higher power design requirements such as 5W, 10W, etc., which can only be selected with an external MOS tube IC.Next, I will recommend several ICs based on comprehensive costs to facilitate the selection of engineers and friends.


7.MAX16819 / MAX16820

The MAX16819 / MAX16820 operate from a 4.5V to 28V input voltage range and have a 5V / 10mA on-chip voltage regulator.The output current is adjusted by a high-side current detection resistor, and a dedicated PWM input (DIM) enables a wide range of pulsed brightness adjustments.


The MAX16819 / MAX16820 are ideal for applications requiring a wide input voltage range.The high-side current detection and built-in current setting circuit reduce the number of external components and provide LED current with ± 5% accuracy.During load switching and PWM brightness adjustment, the hysteretic control algorithm ensures excellent input power supply rejection and fast response.The MAX16819 has 30% inductor ripple current, while the MAX16820 has 10% ripple current.These devices can operate at switching frequencies up to 2MHz, allowing the use of small components.

The MAX16819 / MAX16820 operate over the -40 ° C to + 125 ° C automotive temperature range and are available in 3mm x 3mm x 0.8mm, 6-pin TDFN packages.


Personally recommend 200-500Hz PWM gray frequency adjustment, 1-6pcs LED series larger 25W product design, the recommended price is about 0.5 US dollars.


8.National Semiconductor LM3401

The LM3401 is an external MOS high-power LED driver introduced by the National Semiconductor. It can design a driving current within 3A, the input voltage is higher than 35V, and more than 10 LEDs can be connected in series.


9.MAX16802

The MAX16802A / B is a high-brightness (HB) LED driver control IC. It contains all the circuits needed to design a wide input range LED driver and is suitable for general lighting and display applications.Suitable for low input voltage (10.8V DC to 24V DC) LED driver.When precise adjustment of the LED current is required, an on-chip error amplifier and a 1% accuracy reference can be used.Wide range of brightness adjustment can be achieved by low-frequency PWM brightness adjustment.


The MAX16802 features input undervoltage lockout (UVLO), which sets the input start-up voltage and ensures normal operation when the power is dropped.The MAX16802 has an internal bootstrap undervoltage lockout circuit with a high hysteresis voltage.

This simplifies the design of offline LED drivers.The MAX16802 does not have this bootstrap circuit internally, and it can directly provide bias power from + 12V.The internally fine-tuned 262kHz fixed switching frequency allows optimal selection of magnetic and filter components, resulting in a compact, cost-effective LED driver.

The MAX16802A has a larger duty cycle of 50% and the MAX16802B has a larger duty cycle of 75%.These devices are available in 8-pin μMAX® packages and can operate over the -40 ° C to + 85 ° C temperature range.

Personally recommend 200-500Hz PWM gray frequency adjustment, 1-6pcs LED series connection larger 50W product design, the price is about 1.4 US dollars.