For high-power built-in/external lamp power supplies above 25W, due to high power factor and THD requirements, and the output current is relatively large, the current solution is usually a two-stage rack (APFC+DC/DC). Mainly. The traditional two-stage solution, because it requires two chips to be controlled separately, is often difficult to optimize in terms of chip power supply, drive efficiency and volume, BOM quantity and cost. As a solution for Jingfeng Mingyuan in high-power high-end lamp driving power supply, UR3311 is a two-in-one control chip based on two-stage architecture, which can be applied to BOOST+FLYBACK isolation application or BOOST+BUCK. Non-isolated applications. Suitable for lamp power supplies with high power factor, low THD, low output current ripple requirements. UR3311 chip features 1, patented smart chip power supply 3, the best conversion efficiency critical current mode (BCM) + valley quasi-resonant working mode UR3311 full voltage range PF>0.95, THD<10%; <500ms quick start; Excellent linearity and load regulation, good consistency; Patented algorithms that greatly reduce the number of peripheral devices; Support for isolated and non-isolated applications; Built-in comprehensive protection features; typical application UR3311 Full Voltage Input High PF Low Frequency Flash External Power Supply Application Output LED: 36V/1A PF>0.95 THD<15% 2, schematic 3, PF, DHT and efficiency graph UR3311 You can select the BOOST+FLYBACK and BOOST+BUCK topologies as needed. You only need to change the connection of the MODE pin to select different application topologies. In general, external power supplies for panel lights or other applications should use the BOOST+FLYBACK topology. This topology has the advantages of high security level and good consistency. BOOST+BUCK topology can be used for high efficiency, high efficacy built-in or second-class lighting applications. This topology has the advantages of high efficiency and low application cost. Banknote Value Counting Machine One CIS Suzhou Ribao Technology Co. Ltd. , https://www.ribaoeurope.com
The patented smart chip power supply and critical current valley detection technology without auxiliary winding UR3311 is the simplest and lowest cost design for transformer and inductor design in the current two-stage solution. The power inductor of the front stage BOOST is a single winding inductor, the rear stage isolation FLYBACK is a double winding transformer, and the rear stage non-isolated BUCK is a single winding inductor.
2. The simpler BOOST inductor design keeps the full voltage to maintain high efficiency. When the BOOST stage is the low-voltage input, the latched BOOST output voltage is 280V. When the input voltage rises, the BOOST output voltage is follow-type, which realizes a simpler BOOST inductor design and maintains full voltage to maintain high efficiency.
Both stages are critical current mode (BCM) + valley quasi-resonant mode of operation for optimum conversion efficiency. High precision constant current algorithm and perfect protection function.
UR3311 feature advantages
Output current ripple is less than ±5%, no stroboscopic; up to 88% efficiency (isolation);
Input voltage: 90~270Vac
1, PCB physical map 
