CXLE82129XK, Voltage reducing LED driver chip, non isolated voltage reduction, integrated 800V rectifier bridge, no VCC capacitor, no starting resistor, high-voltage JFET power supply, ± 5% current accuracy, LED short circuit protection, overheating regulation, LED candle light, LED bulb light, ASOP7 package, jtm-ic.com
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[ CXLE82129XK ]"
CXLE82129XK: Highly integrated non isolated buck LED constant current driving solution
In the process of LED lighting industry developing towards higher efficiency, compactness, and reliability, the simplification and integration of driving power supply have become the key to technological breakthroughs. Jiatai Mu（jtm-ic.com）Launched CXLE82129XK The buck type LED constant current driver chip is a model of this trend. It relies onRevolutionary fully integrated designandExcellent constant current performanceIt provides a minimalist, efficient, and reliable solution for LED lighting applications with a full range of inputs from 85Vac to 265Vac.
1、 Chip Core: Fully Integrated Design Leads Industry Innovation
CXLE82129XK is an LED constant current driver chip optimized for non isolated buck topology. Its biggest highlight is unprecedentedsystem-level integrationBuilding multiple core peripheral devices into a single chip:
1.1. Built in 800V rectifier bridgeDirectly connecting to AC input, completely eliminating the need for external discrete rectifier bridges, saving PCB area and material costs.
1.2. Built in 600V ultra fast recovery diodeAs a freewheeling diode, its extremely fast reverse recovery time of 35ns significantly reduces switching losses and improves system efficiency.
1.3. Innovative High Voltage JFET Power Supply TechnologyThe current required for chip operation is directly obtained from the high-voltage bus through the HV pin, therebyCompletely abandoning the necessary VCC capacitors and starting resistors in traditional solutions.
This kind of; Three in One "; The integration strategy makes the application circuit extremely simple and minimizes the number of peripheral components. This not only significantly reduces the overall BOM cost and system power consumption, but also simplifies the production process, improves product consistency and reliability, and is particularly suitable for large-scale standardized lighting products with strict requirements for cost and volume, such as LED bulb lights, candle lights, etc.
2、 Excellent performance: high-precision constant current and powerful protection mechanism
2.1. Accurate constant current control
The chip adoptsInductive current critical continuous mode (BCM) Work with built-in high-precision current sampling circuit. Its constant current control core is based on a precise373mV (typical value) internal threshold voltageThe LED output current is only supplied by an external sampling resistor; RCS The setting and calculation formula are intuitive and concise:
This design ensures that it can achieve full input voltage range and load variation;± 5% high output current accuracyThis ensures a high degree of consistency in the brightness of terminal lighting fixtures.
2.2. Excellent system characteristics
· Wide voltage input (85-265Vac)Compatible with the global power grid, achieving a single design that is universally applicable worldwide.
· Excellent adjustment rateThe performance of line voltage regulation and load regulation is excellent, and the output current does not significantly change with input voltage fluctuations or LED voltage drop changes.
· No flicker experienceThe optimized working mode ensures no flickering phenomenon in low bus voltage or multi lamp parallel applications, improving visual comfort.
2.3. Complete built-in protection function
The CXLE82129XK integrates multiple protection functions to ensure stable system operation:
· LED short circuit protectionWhen a short circuit occurs in the output, the chip automatically enters a low-frequency (about 4kHz) protection mode, with extremely low power consumption, effectively protecting the chip from damage.
· Under voltage protection for chip power supplyEnsure safe shutdown in case of abnormal power supply.
· Overheating regulation functionWhen the chip temperature reaches120℃When adjusting the surface temperature, the output current will be smoothly reduced to control the system temperature rise. This kind of; Soft adjustment; The method avoids the sudden extinguishing of lights caused by overheating and direct shutdown, greatly improving user experience and system reliability.
3、 Flexible Selection and Key Design Guidelines
3.1. Version selection and power coverage
The CXLE82129XK offers three different versions: MK, SK, and AK, corresponding to different built-in power transistor conduction impedances (RD-SON) and output capabilities, making it convenient for engineers to flexibly select based on target power and efficiency requirements.
*Typical working range reference (input voltage: 176-265Vac):*
| version | RDS_ON | Maximum output current (60 ° C environment) | Maximum output power (60 ° C environment) | Applicable power range |
|---|---|---|---|---|
| MK | 22 Ω | 120 mA | 14 W | Small and medium power applications |
| SK | 16.5 Ω | 160 mA | 16 W | Mainstream power |
| AK | 11 Ω | 220 mA | 17 W | Medium to high power demand |
3.2. Key points of energy storage inductor design
The chip operates in critical mode,The selection of inductance is crucialThe calculation formula is as follows:
The system shutdown time must be ensured during design; toff Due to the chip settingsMinimum shutdown time (1.3&ms) And Maximum shutdown time (400μ s) between. Too small an inductance will cause intermittent mode, while too large an inductance will enter continuous mode, both of which will cause the output current to deviate from the set value. Reasonable calculation and selection of inductance are key to ensuring constant current accuracy.
3.3. Core recommendations for PCB layout
Excellent PCB design is the cornerstone for unleashing chip performance and passing EMC testing:
· CS sampling circuitCurrent sampling resistor; RCS ofThe power ground wire must be short and thickAnd adoptSingle point groundingThe method is directly connected to the negative terminal of the input bus capacitor to eliminate noise interference and ensure accurate current sampling.
· HV pin processingIf the process allows, the HV pin should be kept away from low-voltage signal lines such as CS. Appropriately increasing the auxiliary copper area can help dissipate heat from the built-in freewheeling diode.
· Minimize power loopBe sure to shrink your childInput capacitor - power transistor (DRAIN) - power inductorandPower inductor freewheeling diode output capacitorThe large current loop area formed is the most effective measure to reduce electromagnetic interference (EMI).
· Heat dissipation and EMI balance: IncreaseDRAINandGNDThe auxiliary copper area of the pins can significantly improve chip heat dissipation, but it should be noted that excessive auxiliary copper area will increase antenna effect and may worsen EMI, which needs to be balanced in the design.
4、 Wide application prospects
The CXLE82129XK, with its high integration, reliability, and outstanding performance, is the ideal driving core for the following LED lighting products:
· LED bulb lights (A19, A60, etc.)The main product to replace traditional incandescent lamps requires a highly compact driving scheme, low cost, and long lifespan.
· LED candle lights (B35, C35, etc.)Commonly used for decorative and retro lighting fixtures, the driver chip needs to adapt to its narrow internal space.
· Other standard lamp head LED lightingFor example, GU10 spotlights, PAR lights, etc., meet safety requirements while pursuing smaller driving volume.
Five,Typical schematic and internal structure diagram
5.1. Typical schematic diagram
6、 Packaging and Pin Function
7、 Electrical parameters
8、 Scope of work and limit parameters
9、 Conclusion
CXLE82129XK is not just another LED driver IC, it is from Jiataimu（jtm-ic.com）Launched for the future lighting marketDisruptive integrated solutionsIt fundamentally reshapes the design paradigm of non isolated buck LED drivers by eliminating VCC capacitors, starting resistors, and external rectifier bridges, bringing unprecedented simplicity, economy, and reliability to lighting manufacturers.
Choosing CXLE82129XK means choosing a more efficient product development path, a more competitive BOM cost, and a more trustworthy quality commitment. Visit Now;jtm-ic.comGet the complete data manual, detailed application notes, reference designs, and sample applications for CXLE82129XK, and let's work together to drive a new era of green lighting, lighting up a smarter and more energy-efficient life.
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The content of this article is based on the official data manual of CXLE82129XK, and the provided design information is for reference only. In actual product development, it is essential to conduct thorough testing and validation to ensure compliance with specific application requirements.
