Design of high energy efficiency LED driver for LE

Design of high-energy LED driver applied to LED street lamp

with the continuous improvement of LED in almost all aspects of performance and cost, LED lighting is being used in more and more wide application fields, among which led street lamp is a focus of the industry. This paper will introduce the design of a 28 V, 3.3 a off-line high power factor led driver for LED street lighting and other applications. This design is based on the ncl30001 LED driver and ncs1002 constant voltage and constant current controller of ansenmey semiconductor. It uses 90 to 265 V AC voltage to supply power, provides a maximum output power of 90 W, has a high power factor, meets the relevant harmonic content standards, and can cooperate with pulse width modulation (PWM) dimming

single segment topology LED driver + secondary end CVCC controller combination

ncl even the shrinkage of the same material in different batches produced by one factory is different. 30001 is a single segment topology LED driving scheme, and its flexible characteristics are very suitable for new LED lighting products. This off-line LED Driver with single section integrated power factor correction (PFC) and isolated step-down AC-DC power conversion eliminates the dedicated PFC boost section, which can reduce the number of components, reduce the cost of the scheme, and improve the overall energy efficiency of the LED power supply system. It is used in LED street lights, low ceiling lights, exterior wall lights, building lighting and other applications

ncl30001 adopts continuous conduction mode (CCM), which integrates PFC and isolated DC-DC conversion circuit, and provides constant current to directly drive LED. It is equivalent to integrating the AC-DC conversion and LED drive circuits, both of which are located in the lighting fixtures, eliminating the linear or DC-DC converter integrated in the LED light bar. This integrated scheme has fewer power conversion sections, reduces the number of components (such as optical components, LEDs, electronic components, printed circuit boards, etc.), reduces system costs, and supports higher overall energy efficiency of LED power. Of course, this scheme has a higher power density, which may not be suitable for all regional lighting applications. Its optical pattern may be more suitable for low-power led. Typical applications include LED street lights, exterior wall lights, wall washing lights and refrigerator box lighting

ncl30001 controller's other specifications and features include high-voltage starting circuit, voltage feedforward to improve loop response, input undervoltage detection, internal overload timer, latch input, and high-precision multiplier to reduce input line harmonics. Ansenmey semiconductor also provides an isolated single-stage power factor correction LED Driver Evaluation Board for applications requiring direct constant current output in the 40 W to 100 W power range. The current can be adjusted between 0.7 A and 1.5 A, matching with a wider range of high-power and high brightness LED

ncs1002 is a constant voltage and constant current (CVCC) controller at the secondary end, which is suitable for LED street lamps and other regional lighting applications. With the help of ncl30001 controller, a high-efficiency LED driver demonstration board with dimming function can be designed

90 w demonstration board based on ncl30001 and ncs1002

in order to help engineers implement lighting design as soon as possible, ansenmey semiconductor also provides a 90 w constant voltage and current demonstration board, which can accept an extended general input voltage of 90 to 265 VAC (305 VAC can be supported under the condition of replacing components), provide a constant current output range of 0.7 a to 1.5 A and a constant output voltage range of 30 V to 55 V (which can be selected by resistance voltage divider), and the maximum output power is 90 W, It supports 50 to 1000 Hz dimming control and includes a 6-pin interface that can be connected to an optional dimming card for intelligent dimming applications such as analog current regulation/dual brightness level digital dimming. In addition, this demonstration board also provides rich protection features such as short-circuit protection, open circuit protection, over-temperature protection, over-current protection and over-voltage protection. The test shows that the energy efficiency of this demonstration board is higher than 87% under the conditions of 50 W output power, 1000 mA output voltage/48 V forward voltage drop, and the power factor is higher than 0.9 under the conditions of 50% to 100% load. At the same time, it meets the IEC class C equipment harmonic content standard

Figure 1: top view of the demonstration board

because this design can have a power level comparable to the standard ncl30001 evaluation board (50v2a), the change of circuit principle lies in the design of the transformer and the constant current/constant voltage secondary side control circuit based on ncs1002. Figure 2 shows the primary side circuit. The flyback transformer of this design is derived from the secondary winding of the original design, which can meet the new maximum voltage and current requirements. The inductance and overall structure of the primary winding are basically the same. The 277 VAC input can use the appropriate rated voltage to change the "X" and "Y" capacitors of the EMI input filter

Figure 2: schematic diagram of primary side of ncl30001 CVCC 90 w demonstration board

using ncl30001 continuous conduction mode power factor correction single-stage flyback controller, it can realize constant current LED driver for regional lighting applications such as elevated, tunnel, parking lot and road lighting. This special design is optimized for LEDs that need more than 3A driving capacity in talent cultivation, such as csm360 and sst90 of luminus devices. This design can support up to eight sst90 devices in series or two csm360 devices. The nominal forward voltage of csm360 LED is 12.8 v when the driving current is 3.2a, which depends on the color temperature and luminous flux, and can produce lumens

the secondary side control circuit is shown in Figure 3. In this design, the output voltage is determined by a resistivity, and the output current is also set based on a resistivity. Therefore, since both lignin and synthetic rubber containing acrylonitrile and butene (called nitrile rubber) have chemical groups with uneven electron dispersion, only two resistances need to be changed: one is the output voltage divider R34, and the other is R32, which is part of the current setting circuit. In addition, because the output voltage is low and the output current is high, the output capacitance is increased and the rated voltage of the capacitor is reduced

Figure 3: schematic diagram of secondary side

with this circuit, CVCC secondary detection of 30 Vout LED Driver with PWM dimming input and optional dimming card can be realized

summary

high energy efficiency lighting is becoming a focus of competition in the industry. At this time, we need to add a DC input signal to the amplifier unit through the workstation. This paper focuses on the 90 w LED Driver Design of ansenmey semiconductor for LED street lamp application. This design provides high power factor, meets the IEC class C equipment harmonic content standard, and can cooperate with PWM dimming. Customers can speed up the product launch process by using the energy-efficient products and reference designs of ansenmey semiconductor. (end)