The CXLE8434XS is designed specifically for isolated flyback LED constant current power supplies, supporting a full range of input voltages from 85Vac to 265Vac, and is suitable for mainstream global power grid standards. The chip operates in the intermittent mode of inductor current, with high system stability and no need for complex loop compensation design.
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[ CXLE8434XS ]"
CXLE8434XS: High precision flyback LED constant current driver chip, integrated high voltage power supply, minimalist peripheral design
In the field of LED lighting power supply design, efficient, stable, and streamlined driving solutions have always been the goal pursued by engineers.CXLE8434XSAs a high-precision flyback LED constant current driver chip, with itsNo VCC capacitor, no starting resistor, integrated high-voltage power supplyWith outstanding features, it has become a highly competitive choice in the design of small and medium power LED lighting fixtures. This article will comprehensively analyze this high-performance driver chip from the aspects of chip overview, technical characteristics, application scenarios, and design suggestions.
1、 Chip Overview and Core Advantages
CXLE8434XSSpecially designed for isolated flyback LED constant current power supply, supporting a full range of input voltages from 85Vac to 265Vac, suitable for mainstream global power grid standards. The chip operates in the intermittent mode of inductor current, with high system stability and no need for complex loop compensation design.
Its biggest highlight isHighly integrated and minimalist peripherals：
· Internally integrated high-voltage power switch, using gate demagnetization detection technology and high-voltage JFET power supply technology.
· No need for VCC capacitors and starting resistorsSignificantly simplifying peripheral circuits, reducing system costs and volume.
· No need for auxiliary winding detection and power supply, further reducing transformer complexity.
The chip adoptsSOP7 encapsulationSuitable for LED lighting fixtures with power below 12W, such as bulb lights, tube lights, and other common lighting products.
2、 Main features and protective functions
CXLE8434XSEquipped with multiple practical features and comprehensive protection mechanisms, the system ensures reliable operation in various abnormal situations:
2.1. Key Features:
· ± 5% LED output current accuracy ensures lighting consistency
· Support parallel connection of multiple lights without flickering
· The chip has built-in power supply undervoltage protection
· Overheating regulation function, intelligent temperature control
· The recommended operating frequency for the system is 65kHz~70kHz, balancing efficiency and EMI performance
2.2. Multiple protection functions:
· LED short circuit protectionDuring a short circuit, the system automatically switches to working at a low frequency of 3.3kHz, with extremely low power consumption
· LED open circuit protectionTrigger OVP logic and lock when open circuit, automatically reset and restart after 10ms
· Chip overheating regulationGradually reduce the output current when the junction temperature exceeds 140 ℃ to prevent overheating and damage
3、 Electrical parameters and working characteristics
In terms of electrical performance,CXLE8434XSOutstanding performance:
· power supply voltageHV pin withstand voltage up to 650V
· Current sampling thresholdTypical value of 380mV, accuracy range of 371mV~389mV
· Conduction impedanceAS version 25Ω ， BS version 14Ω Meet different power requirements
· Working frequency range：65kHz~70kHz， The system is stable and easy to design
· Overheating control pointChip surface temperature 140 ℃
The chip supports two versions (AS/BS), with output power ranging from 3W to 7W, meeting the needs of most small and medium power LED lighting applications.
4、 Typical Applications and Design Guidelines
4.1. Application Scenario:
· LED bulb light
· LED downlight
· Other types of LED lighting equipment
4.2. Output current setting:
The output current of LED is determined by the transformer turns ratio and sampling resistance, and the formula is as follows:
among which
Flexible design and easy adjustment.
4.3. PCB design suggestions:
· Ground wire layoutThe sampling resistor ground wire should be short and direct, separated from the chip ground wire, and finally connected to the bus capacitor ground terminal
· Power LoopMinimize the loop area of transformers, MOSFETs, absorption networks, secondary diodes, and output capacitors as much as possible to reduce EMI
· thermal designThe Drain pin can be appropriately increased in copper area to enhance heat dissipation performance
· Safety distanceThe NC pin must ensure sufficient creepage distance and comply with safety regulations
5、 Packaging and ordering information
CXLE8434XSAdopting SOP7 packaging, the size is compact and suitable for high-density PCB layout. Its working temperature range is -40 ℃ to 105 ℃, suitable for various environmental conditions. When ordering, AS or BS versions can be selected according to power requirements.
VIRelated products; more...
7、 Conclusion
CXLE8434XSWith its high integration, minimalist peripherals, multiple protections, and stable performance, it provides an efficient and reliable solution for LED lighting power supply design. Whether used for bulb lights, tube lights, or other lighting products, it can significantly reduce system costs and volume while ensuring performance.
If you are looking for a constant current driver chip suitable for small and medium power LED lamps,CXLE8434XSWorth your attention. For more product details, technical information, and sample applications, please visit jtm-ic.comWe will provide you with professional technical support and services.
The content of this article is based on the official specification book of CXLE8434XS, for reference only. Please refer to the actual circuit verification for specific design.
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