Against the backdrop of global advocacy for energy conservation, consumption reduction, and green lighting, the efficiency, reliability, and cost of LED driving technology have become the core of market competition. The CXLB82129X launched by Shanghai Jingtong Microelectronics (jtm-ic. com) is a non isolated step-down LED constant current driver chip designed specifically for 85Vac-265Vac wide voltage inputs. It provides highly competitive core solutions for general lighting applications such as LED bulb lights and candle lights, thanks to its high integration, minimalist peripheral design, and excellent performance
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[ CXLE82129X ]"
CXLE82129X: A Fully Integrated Buck Constant Current Solution for Innovating Non Isolated LED Drivers
Against the backdrop of global advocacy for energy conservation, consumption reduction, and green lighting, the efficiency, reliability, and cost of LED driving technology have become the core of market competition. Jiatai Mu（jtm-ic.com）LaunchedCXLE82129X, is a non isolated step-down LED constant current driver chip designed specifically for 85Vac-265Vac wide voltage input. It relies onHighly integrated, minimalist peripheral design, outstanding performanceThree major features provide highly competitive core solutions for general lighting applications such as LED bulb lights and candle lights.
1、 Chip Overview: Reshaping the Path to Simplification
CXLE82129X adopts advanced technologyInductive current critical continuous mode (BCM)The work has achieved excellent line voltage regulation and load regulation. Its most revolutionary breakthrough lies inExtremely high integration level：
· Built in 800V rectifier bridgeDirectly connect to AC power, eliminating the need for external rectifier bridges, saving space and costs.
· Built in 600V ultra fast recovery diodeAs a freewheeling diode, it has high efficiency and fast reverse recovery time.
· Integrated High Voltage JFET Power Supply TechnologyThe current required for chip operation is directly provided by the high-voltage line through the HV pin,No need for traditional VCC capacitors and starting resistors.
This kind of; Three in One "; The highly integrated design reduces the number of peripheral components, simplifies the PCB layout, significantly reduces the system volume, and significantly lowers the overall BOM cost and power consumption, making it particularly suitable for large-scale consumer lighting products that are sensitive to space and cost.
2、 Core technical features and performance advantages
2.1. High precision constant current output
The chip is equipped with high-precision current sampling and constant current control circuits to ensureLED output current accuracy up to± 5%The output current does not drift with changes in inductance and LED operating voltage, ensuring high consistency in lamp brightness even during different batches of production or input voltage fluctuations, thereby improving product quality and user experience.
2.2. Excellent system performance
· Low bus voltage does not flash the lightSolved the flicker problem that is prone to occur in traditional solutions during voltage drops.
· Multiple lights connected in parallel without flickeringStable constant current characteristics support parallel use of multiple lamps, with strong system compatibility.
· Wide voltage input (85-265Vac)Compatible with major global power grid voltages, achieving universal use of a single version worldwide.
2.3. Comprehensive protection function
CXLE82129X has multiple built-in protection mechanisms to ensure the safety and reliability of the system in various abnormal situations:
LED short circuit protectionWhen the output is short circuited, the system automatically switches to a low-frequency working mode of about 4kHz, with extremely low power consumption to ensure chip safety.
Under voltage protection for chip power supplyEnsure stable shutdown of the system in case of insufficient power supply.
Overheating regulation function (OTP)When the junction temperature of the chip exceeds the set point (typically 140 ℃), the output current is automatically smoothed down to control the temperature rise, achieve temperature closed-loop, avoid sudden light extinction caused by thermal shutdown, and improve reliability.
2.4. Flexible output configuration
The chip offers four different versions of internal resistance (RD-SON): L, M, S, and A, corresponding to different maximum output currents and power capabilities (see table below), making it convenient for engineers to flexibly select based on target power and achieve the best balance between efficiency, cost, and temperature rise.
*Recommended work scope example (Vin: 176-265Vac):*
| version | Maximum output current (60 ° C) | Maximum output power (60 ° C) | feature |
|---|---|---|---|
| L | 100 mA | 12 W | Suitable for low-power applications |
| M | 120 mA | 14 W | Universal medium power |
| S | 160 mA | 16 W | Mainstream medium to high power |
| A | 220 mA | 17 W | High current output capability |
3、 Design Guidelines and Application Analysis
3.1. Constant current setting and inductance calculation
The LED output current is measured by a sampling resistor connected between the CS pin and GND; RCS setting The calculation formula is concise and clear:
Among them, 0.373V is the precise current detection threshold voltage inside the chip.
The selection of energy storage inductor (L) is crucialIt determines whether the system operates stably in the ideal critical mode. The inductance value can be calculated using the provided formula, and it is necessary to ensure the system's shutdown time when the input voltage changes; toff To ensure constant current accuracy, it falls between the minimum (1.3μ s) and maximum (400μ s) turn off times allowed by the chip.
3.2. Core recommendations for PCB layout
Excellent PCB design is the key to maximizing chip performance and passing EMC testing:
· CS sampling circuitThe power ground wire of the sampling resistor shouldShort and thickAnd independently connected to the negative terminal of the input bus capacitor to eliminate noise interference and ensure accurate sampling.
· HV pinIf the process allows, it should be kept away from low-voltage signal pins such as CS, and the auxiliary copper area should be appropriately increased to assist in the heat dissipation of the built-in freewheeling diode.
· Power Loop: Minimize as much as possible byInput capacitor, power transistor (DRAIN), inductorThe power loop area formed, andInductance, freewheeling diode, output capacitorThe formed loop area is the most effective means of reducing electromagnetic interference (EMI) radiation.
· Heat dissipation treatment: Increase appropriatelyDRAINandGNDThe auxiliary copper area of the pins can effectively improve the heat dissipation capability of the chip, but attention should be paid to balancing it with EMI performance.
4、 Packaging and Pin Function
Five,Typical schematic and internal structure diagram
5.2. Internal Structure Diagram
6、 Electrical parameters
7、 Typical application areas
CXLE82129X, with its high integration, high reliability, and excellent constant current characteristics, has become the ideal driving heart for the following lighting products:
· LED bulb lightThe main product to replace traditional incandescent and energy-saving lamps requires a small driving solution, low cost, and long lifespan.
· LED candle lampCommonly used for decorative and retro lighting fixtures, the driver chip needs to be able to adapt to the heat dissipation challenges of small-sized lamp bodies.
· Other E27/E14/B22 lamp head LED lightingFor example, tube lights, PAR lights, etc., they need to be compatible with existing lamp sockets and meet safety requirements.
8、 Related products; more...
9、 Conclusion
CXLE82129X is not just a driver chip, but also a Jiataimu（jtm-ic.com）Launched for the general LED lighting marketSystem level solutionIt fundamentally simplifies the circuit and reduces overall costs through innovative integrated design, while ensuring high performance and long lifespan of terminal lighting fixtures with high-precision constant current and complete protection functions.
For lighting manufacturers who pursue excellent cost-effectiveness, design simplicity, and high reliability, choosing CXLE82129X means choosing faster time to market, more stable product quality, and stronger market competitiveness. Visit jtm-ic.comBy obtaining complete data manuals, application circuit diagrams, and sample support, let's work together to light up a more efficient and reliable future of green lighting.
The content of this article is based on the official data manual of CXLE82129X, and the design is for reference only. In practical applications, please conduct sufficient testing and verification according to specific situations.
