CXAC85268 is a highly integrated PWM current mode switching power supply controller that uses classic DIP8 and SOP8 packaging, greatly reducing system costs while ensuring performance. The chip integrates a fixed frequency oscillator internally, which has a frequency jitter function to effectively reduce electromagnetic interference (EMI). At the same time, it provides comprehensive protection mechanisms including overvoltage, undervoltage, overtemperature, overload, soft start, and short circuit protection, ensuring the safe and stable operation of the system under various working conditions.
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[ CXAC85268 ]"
CXAC85268 PWM Current Mode Switching Power Supply Controller: A Highly Integrated Power Supply Solution
In the field of power management chips, high integration, high performance, and reliability have always been the core goals pursued by engineers. CXAC85268, as a PWM current type controller designed specifically for switching power supplies, has become an ideal choice for various power systems due to its comprehensive protection functions, excellent EMI performance, and flexible application characteristics. This article will comprehensively analyze the technical characteristics, working modes, protection mechanisms, and application design of CXAC85268, providing engineers with a complete solution reference.
1、 Overview and Core Values of Chips
CXAC85268 is a highly integrated PWM current mode switching power supply controller that uses classic DIP8 and SOP8 packaging, greatly reducing system costs while ensuring performance. The chip integrates a fixed frequency oscillator internally, which has a frequency jitter function to effectively reduce electromagnetic interference (EMI). At the same time, it provides comprehensive protection mechanisms including overvoltage, undervoltage, overtemperature, overload, soft start, and short circuit protection, ensuring the safe and stable operation of the system under various working conditions.
This controller is particularly suitable for cost sensitive and high reliability switching power supply applications. Its low starting current and operating current characteristics further enhance system energy efficiency and meet the stringent requirements of modern electronic devices for power management.
2、 Core technical features
2.1. Efficient power management
• Low starting and operating currentOptimize system energy efficiency and reduce standby power consumption
• Fixed frequency PWM controlProvide stable switching frequency and simplify output filtering design
• Built in soft start functionReduce startup shock and extend the service life of power devices
2.2. Advanced EMI suppression technology
• Built in TikTok functionBy slightly modulating the switching frequency, dispersing harmonic energy, significantly reducing conducted and radiated EMI
• Frontier Hidden Banking (LEB) TechnologyEliminating current sampling errors at the moment of switching and improving system stability
2.3. Comprehensive protection mechanism
• Cycle by cycle current limitationReal time monitoring and limiting peak current to prevent overcurrent damage
• Abnormal overcurrent protectionDealing with extreme situations such as short circuits to ensure system safety
• Multiple protection integrationIncluding overvoltage, undervoltage, open-loop, overload, over temperature, and output short circuit protection
• Automatic recovery functionAfter troubleshooting, the system can automatically resume normal operation
2.4. Accurate current control
• Built in peak current compensationEnsure constant output power across the entire voltage range
• Synchronous slope compensationPrevent subharmonic oscillation and improve system stability
3、 Typical application scenarios
CXAC85268 is widely used in the following fields due to its excellent performance and rich protection functions:
• AC/DC adapters and chargersProvide stable power supply for consumer electronic devices
• Industrial switch power supplyPower modules suitable for automation equipment and control systems
• LED driver power supplyProvide constant current output to ensure stable operation of LED lighting system
• Household appliance power supplySuch as televisions, set-top boxes, small appliances, etc
• Open switch mode power supply (SMPS)Various universal switch power supply design schemes
4、 System Design and Working Principle
4.1. Initiation and workflow
After the system is powered on, the chip starts working through the startup circuit. The built-in soft start function gradually increases the pulse width of the switch, smoothly establishes the output voltage, and reduces the current impact on power devices. Under normal working conditions, the chip performs PWM modulation at a fixed frequency and adjusts the duty cycle in real-time through a feedback network to maintain stable output voltage.
4.2. EMI optimization design
The built-in frequency jitter function of the chip disperses harmonic energy over a wide frequency band by performing slight frequency modulation based on the center frequency, significantly reducing the EMI peak at specific frequency points. This feature makes it easier for the system to meet EMC standard requirements, while reducing the number of peripheral filtering components and lowering system costs.
4.3. Detailed explanation of protection mechanism
• Overvoltage/undervoltage protectionMonitor the power supply voltage and turn off the output in case of abnormalities
• over-temperature protectionAutomatically limit power or turn off output when the junction temperature of the chip exceeds the safety threshold
• Overload and short circuit protectionReal time response to abnormal working conditions through periodic current detection
• Open loop protectionWhen the feedback loop is open, the system enters a protective state to prevent damage
4.4. PCB layout suggestions
• Power path designThe power loop area should be minimized to reduce parasitic inductance and EMI radiation
• Grounding strategyUsing star grounding or single point grounding, separate power ground and control ground
• Decoupling capacitor arrangementThe VDD bypass capacitor should be closely attached to the chip pins to ensure stable power supply
• Heat dissipation considerationsFor DIP8 packaging, the copper skin area can be appropriately increased to assist in heat dissipation
5、 Market competitive advantage
CXAC85268 has significant advantages among similar products:
• high integrationReduce the number of peripheral components, lower system costs and PCB area
• comprehensive protectionIntegrated multiple protection functions to enhance system reliability
• Excellent EMI performanceBuilt in frequency jitter function simplifies EMC design difficulty
• Flexible packagingProvide DIP8 and SOP8 packaging options to meet different application requirements
• cost optimizationProvide highly competitive prices while ensuring performance
6、 Product packaging form and pin function
Seven,Typical Applications
eighty percentConclusion
The CXAC85268 PWM current mode switching power supply controller provides an ideal solution for various switching power supply systems with its outstanding performance, comprehensive protection functions, and excellent cost-effectiveness. Whether it's consumer electronics adapters, industrial power supplies, or LED driver applications, this chip can provide stable and reliable power management support, helping engineers shorten development cycles and optimize system performance.
With the continuous improvement of power efficiency standards and the trend towards miniaturization of electronic devices, CXAC85268 will continue to play an important role in the field of power management, providing core power support for various electronic devices.
If you need to obtain CXAC85268 samples, technical information, or apply for technical support, please visitJTM-IC official websiteWe are committed to providing customers with high-quality power management integrated circuit solutions, helping your products gain a competitive advantage in the global market.
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