CXLE82136XS is a high-performance driver chip designed for non-isolated step-down constant-current LED power supply, supporting full range input voltage of 85Vac to 265Vac. The chip uses inductor current critical continuous mode, integrates 500v high-voltage power switch internally, combines grid demagnetization detection technology and high-voltage JFETs power supply architecture, without external VCC capacitor and starting resistor, greatly simplifies peripheral circuit, significantly reduce system cost and volume.
-
[ CXLE82136XS ]"
CXLE82136XS external OVP step-down LED driver chip-JTM-IC high anti-interference SOP10 packaging solution
Under the development trend of LED lighting system design towards high reliability, strong anti-interference and flexible layout, the performance and packaging form of the driver chip become the key to determine the product competitiveness. JTM-IC (jtm-ic.com) launched CXLE82136XS external OVP step-down LED constant current driver chip, with its excellent anti-interference ability, support multi-lamp parallel without flicker, and compact SOP10 package, it is of high performance, the highly integrated LED lighting scheme provides an ideal choice. This article will deeply analyze the chip architecture, core technologies, design points and application scenarios to help engineers achieve more stable and intelligent lighting system design.
I. Overview of CXLE82136XS chips
CXLE82136XS is a high-performance driver chip designed for non-isolated step-down constant-current LED power supply, supporting full range input voltage of 85Vac to 265Vac. The chip uses inductor current critical continuous mode, integrates 500v high-voltage power switch internally, combines grid demagnetization detection technology and high-voltage JFETs power supply architecture, without external VCC capacitor and starting resistor, greatly simplifies peripheral circuit, significantly reduce system cost and volume.
The highlight is thatExternal OVP function with high anti-interferenceAndIntelligent Enable control, can effectively suppress false protection caused by external interference, and support intelligent lighting applications such as switch color mixing and human body induction. Chip useSOP10 package, compatible with CXLE82135XJ DIP7 pin layout, easy to design upgrade and production adaptation.
II. Core features and technical advantages
· Strong anti-interference OVP design: the external OVP circuit has high anti-interference capability to ensure the stable operation of the system in complex electromagnetic environment and avoid false triggering.
· Multi-lamp parallel without flicker: optimize the control mechanism, support the parallel use of multiple LED lights, no flicker phenomenon, improve the overall lighting efficiency and consistency of the system.
· Intelligent Enable control: The ROVP pin supports the enable function. The chip starts when the voltage is higher than 0.3V, and the output is turned off when the voltage is lower than 0.1V. It is suitable for dimming, color mixing, induction control and other scenarios.
· High Integration Design: internally integrated high-voltage power tube and JFETs power supply, no auxiliary power supply components is required, and the system structure is simple.
· Wide input voltage range: Compatible with 85Vac to 265Vac global grid standards.
· High precision stable output current: the output current accuracy reaches ± 5%, with excellent line voltage and load adjustment rate.
· Comprehensive protection mechanism: Integrated LED short circuit protection, power supply undervoltage protection, external OVP and overheating regulation and other multiple protection.
· Compact SOP10 package: small package size, good heat dissipation performance, suitable for high-density PCB layout.
III. Internal structure and working principle
CXLE82136XS is highly integrated internally, including Vcc power supply module, undervoltage locking, OVP control logic, overheating regulation, constant current control and logic core, leading edge blanking and high precision current detection circuit.
Startup Process: After the system is powered on, the bus voltage supplies power to the inside of the chip through the HV pin, and the control circuit starts to work after reaching the start threshold. When the chip is running normally, its work current is continuously provided by the internal high-voltage JFETs.
Constant current control mechanism: The chip works in the critical conduction mode, and the closed-loop constant current is realized by detecting the peak inductor current cycle by cycle. The external current sampling resistor RCS of the CS pin controls the Power Tube switch by comparing the voltage at both ends with the internal 373mV threshold.
The average LED output current is determined by the following formula:
Value to accurately set the output current. Just adjust the RCS resistance
3.2. Internal structure
IV. Design and selection of key peripheral components
4.1. Design of energy storage inductance
Inductance is the core component to ensure the stable operation of the system in critical mode. The calculation formula is as follows:
Where IPK = 2×iled, f is the operating frequency of the system.
To ensure constant current accuracy, power tube off-time toff must meet the following requirements:
Beyond this range, the system may enter intermittent or continuous mode, causing the output current to deviate from the design value.
4.2. External OVP resistance setting
The open circuit protection voltage can be set by the resistor ROVP connected between the ROVP pin and ground. The typical output current of this pin is 90 μA.
First, estimate the demagnetization time TOVP based on the target protection voltage VOVP:
Then calculate ROVP:
Note: If the OVP function is not required, the ROVP pin can be suspended. If the Enable function is required, make sure that the ROVP resistance is> 5kΩ.
V. Perfect protection function system
CXLE82136XS built-in multi-level protection mechanism to ensure system safety and reliability under various abnormal conditions:
· LED short circuit protection: when the output is short circuit, the system automatically enters the low frequency (4kHz) intermittent working mode, with extremely low power consumption to prevent thermal damage.
· Power supply undervoltage protection: monitor the internal power supply voltage in real time to avoid system misoperation under undervoltage.
· High anti-interference open circuit protection: the external OVP has strong anti-interference capability and precisely sets the protection point to prevent the output voltage from being too high when the LED is open.
· Overheating adjustment: When the chip junction temperature exceeds 140℃, the output current is automatically linearly reduced to realize closed-loop temperature control and improve the long-term reliability of the system.
VI. PCB layout and heat dissipation design guide
Reasonable PCB design is crucial to system stability, EMI performance and heat dissipation:
6.1. Heat dissipation optimization layout: GND, ROVP, DRAIN, and CS pins can be connected to adjacent NC pins to expand the heat dissipation area by copper foil and improve the overall heat dissipation capability of the chip.
6.2. Current sampling loop: The Power ground wire of the sampling resistor should be short and thick, and be independently routed to the grounding terminal of the input bus capacitor, which is separated from the chip signal.
6.3. High voltage pin isolation: the HV pin should be far away from low-voltage sensitive pins such as CS, and try to plus-sized its connection area to assist heat dissipation during layout.
6.4. Power loop minimization: reduce power inductor, power tube inside the chip, the primary loop formed by the input capacitor, and the secondary loop area formed by power inductor and the output capacitor to reduce electromagnetic radiation (EMI).
6.5. Grounding treatment: The GND pin of the chip must be directly connected to the negative terminal of the input bus capacitor, not only to the rectifier Bridge output terminal.
7. Typical application scenarios
CXLE82136XS is very suitable for the following applications due to its advantages of high anti-interference, support for multi-lamp parallel connection and compact packaging:
·LED bulb, downlight, panel light and other commercial and home lighting
·Systems that require parallel connection of multiple lights and require no flicker
·Applications with complex electromagnetic environments such as outdoor or industrial lighting
·Intelligent lighting system supporting intelligent dimming, color mixing or human body induction
VIII. Packaging and ordering information
CXLE82136XS adopts SOP10 package with 1.27mm pin spacing and compact package size, which is suitable for automatic surface paste production. The order model is CXLE82136XS, and the package is in the form of braiding, with 4000 pieces per plate, which is convenient for mass production and material management.
IX,Electrical Performance
Ten,Related productsmore...
Xi,Conclusion
CXLE82136XS integrates high-precision constant current, high anti-interference protection, intelligent control, multi-lamp parallel without flicker and compact packaging, providing a high-performance and high-reliability solution for non-isolated LED lighting drivers. Its excellent anti-interference capability and system compatibility make it an ideal choice for high-power intelligent lighting applications.
JTM-IC has always been committed to providing leading power management chip solutions for the global lighting industry through continuous technological innovation. For detailed technical information, reference design, or sample application for CXLE82136XS, please visit the official website of JTM-IC:jtm-ic.com.
This article is provided by the JTM-IC technical team. Welcome to reprint it. Please specify the source fromjtm-ic.com.
