1 Introduction

This document describes a proposed solution for a 120W LED driver that includes an AC-DC converter for flyback bias regulation, a boost converter for power factor correction (PFC), a LLC resonant converter current and voltage for two constant LED channels or single boost converter current and dimming control. The input voltage range is 85 VRMS – 300 VRMS for a single LED channel with a DC output current of 2.4 A and a maximum current of 50 V, or for two LED channels, constant current at 100 V and 1.2 V dimming.

Power Main Utilization: FSL117MRIN – Green Mode Fairchild Power Switch (FPS 8482 ;) FL7930B – CRM PFC Controller Fan 7631 – Half Bridge LLC Controller Fan 73402 – Single Channel Boost Controller (per controller) FCPF190N60E and FCPF 600 N60Z – Fairchild SuperFET® Technology FDPF14N30 – Fairchild UniFET® Technology N-Channel MOSFET FFPF08H60S – Fairchild Ultra High Speed Rectifier MBR20 200 CT – Fairchild Schottky Rectifier

; RURD620CCS9A – Fairchild Ultra-Fast Recovery Rectifier (Discrete) This document contains important information (such as schematics, bill of materials, printed circuit board layout, transformer design files) and typical operation to support the characteristics of this evaluation board. 1.1. FSL117MRIN Overview The FSL117MRIN is an integrated pulse width modulation (PWM) controller, 700 volt sensor designed for offline switch mode power supplies (SMP) with minimal external components. The PWM controller includes an integrated fixed frequency oscillator, Line Over Voltage Protection (LOVP), Under Voltage Lockout (UVLO), Leading Edge Blanking (LEB), optimized gate driver, internal soft start, temperature compensated precision current source, For loop compensation and self-protection circuits. Compared with discrete MOSFET and PWM controllers, the fsl11mrin can reduce overall cost, component count, size and weight; while improving efficiency, productivity and system reliability. This device provides a basic platform for cost-effective design of flyback converters.

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Advanced Soft Pulse Mode, Low Standby Power and Low Noise Low Electromagnetic Interference (EMI) Random Frequency Fluctuation (RFF) Pulse by Pulse Current Limit Overload Protection (OLP), Over Voltage Protection (OVP), Abnormal Over Current Protection (AOCP), Internal Thermal Shutdown (TSD), Hysteresis, Output Short-Circuit Protection (OSP), Line Over-Voltage Protection (LOVP) and Under-Voltage Hysteresis Lockout (UVLO) Low Operating Current (0.4mA) in Pulse Mode Internal Startup Circuit Internal Avalanche Rugged 700 V-sensor built-in soft-start: 15 ms auto-restart mode

FL7930C overview

The FL7930C is an active power factor correction (PFC) controller for low to high power lumen applications operating in critical conduction mode (CRM). It generates the MOSFET turn-off signal using voltage-mode PWM that compares the internal ramp signal with the error amplifier output. Because the voltage-mode CRM PFC controller does not require rectified AC line voltage information, it saves input power loss to the voltage sensing network. FL7930B provides over-voltage, open feedback, over-current, no input voltage detection, under-voltage lockout protection. The FL7930B can be used if the INV pin voltage falls below 0.45 V and the operating current is reduced to a very low level. Using a new variable real-time control method, Total Harmonic Discharge (THD) is lower than conventional CRM-boost PFC ICs. The FL7930C provides a PFC ready pin that can be used to turn off the boost power stage when the power factor corrected output voltage reaches the proper level (with hysteresis).

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Additional PFC ready function Input missing voltage detection circuit maximum switching frequency limit. Internal soft-start to prevent overshooting (OCP) Undervoltage Lockout (UVLO) with 3.5 V hysteresis Low start-up (40 μA) and operating current (1.5 mA) Totem pole output with high state clamp + 500 /-800 mA peak gate drive current

FAN7631 Overview

The FAN7631 is a pulse frequency modulation controller resonant converter for a high-efficiency half-bridge, including a high-side gate drive circuit, an accurate current-controlled oscillator, and various protection functions. Features of the FAN7631 include variable dead time, up to 600 kHz operating frequency such as LUVLO, and optional latch or a/R protection using the LS pin for user convenience. Zero Voltage Switching (ZVS) technology reduces switching losses and improves system reliability significantly. ZVS also significantly reduces switching noise, which enables small electromagnetic interference (EMI) filters. Provided with everything necessary to build the FAN7631 is a reliable, robust resonant converter that simplifies design and improves productivity and performance. The FAN7631 can be used in resonant converter topologies such as series resonant, parallel resonant and LLC resonant converters.

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50% Duty Cycle Half-Bridge Resonant Inverter Controlled Converter Topology High Efficiency Operating Frequency Up to 600 kHz with Zero Voltage Switching (ZVS) High Gate Drive Current +500mA/-1000mA Precisely Adjustable Output Overvoltage Protection (OVP) Programmable dead time using resistors Frequency limited (programmable) pulse skipping and burst operation under light load conditions Simple via selectable latch or A/R using FI or LS pin Remote on/off control protection functions; Over Voltage Protection (OVP), Overload Protection (OLP), Over Current Protection (OCP), Abnormal Over Current Protection (AOCP), Internal Thermal Shutdown (TSD) and High Precision Line Under Voltage Lockout ( LUVLO) level change OCP function during startup.

FAN73402 Overview

The FAN73402 is a single-channel boost controller that integrates an N-channel power MOSFET for PWM dimming using Fairchild's proprietary planar double-diffused MOSFET (DMOS) technology. This integrated circuit is used to drive high current LEDs. Using current mode control, the slope is programmable to prevent compensation of sub-harmonic oscillations. The protection provided by the integrated circuit includes: open LED protection, overvoltage protection, direct short circuit protection and high reliability of the system. In case of abnormal LED string condition. PWM dimming and analog dimming functions can be implemented independently. Internal soft-start prevents inrush current into the output capacitor during startup.

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Single-channel boost LED switch Internal power MOSFET for PWM dimming: RDS(on)=1.0Ω, BVDSS=200 V at VGS=10 V; current-mode PWM control internal programmable slope compensation power supply Wide voltage range: 10 V to 35 V; LED current regulation: ? 1%; Programmable Switching Frequency Analog and PWM Dimming Width Dimming Ratio: On Time = 10µs to DC Cycle-by-Cycle Current Limit Thermal Shutdown: 150°C On LED Protection (OLP) Over Voltage Protection (OVP) Over Current Protection (OCP) Generate error flag (for external load switch) Internal soft start

Transformer Design

Flyback Transformer (TS801) Core: EPC1717 (TDK) Spool: 10-pin

PFC Inductor (LP801)

Core: PFC3819QM (TDK)

Bobbin: PQM3819, 8 needles

LLC Transformer (TM801); Core: SRX43EM (TDK); Spool: EEX4333P12-1, 12-pin

Test Conditions and Equipment

system efficiency

System efficiency is measured at 85~140 VAC [low line, 60 Hz] and 180~300 VAC [high line, 50 Hz] input voltage range. The result is a PFC and LLC converter that can connect and measure a single LED channel [50 V/2.5 A] under rated load conditions 30 minutes after AC power is turned on.

System efficiency is measured at 85~140 VAC [low line, 60 Hz] and 180~300 VAC [high line, 50 Hz] input voltage range. The result is a PFC and LLC converter that can connect and measure a single LED channel at 50% load [50 V/1.25 A] 30 minutes after AC power is turned on.

The table shows the 85 VAC~140 VAC [low line, 60 Hz] and 180~300 VAC [high line, 50 Hz] input voltage ranges. when the PS-ON switch is off.

Power factor and total harmonic discharge (THD) Power factor and THD ~ 300 VAC [high line, 50 Hz] input voltage range was measured at 85~140VAC [low line, 60Hz] and 180°C. The measured data is the entire system with two channel LED loads connected.

Constant current and constant voltage regulation

Tables and graphs show typical CC/CV performance on the board; stable CC performance is shown over a wide input range. The result is a single LED channel converter [CR mode] where the PFC and LLC are connected and measured with an electronic load. surface. Output voltage change constant current regulation (25v~50v)

Overall startup performance

Figure shows start-up performance; including flyback, boost, LLC resonant converter, single channel boost converter at rated output load. Output input voltage is 85 VAC and 300 VAC condition when AC input power switch is on; CH1: VDD_Flyback (10 V/div), CH2: VIN (200 V/div), CH3: VLED (50 V/div) div), CH4:ILED (0.5 A/div), time scale: 200 ms/div.

Figure shows the start and stop performance operation of PS-ON switches: including boost, LLC resonant converters and single-channel boost converters. After the PS-ON switch is turned on, the output load current starts to flow for about 59 ms. Turn off when the PS-ON switch is turned off in standby; CH1: VDDPFC (10 V/div), CH2: V PS-ON (2 V/div) , CH3: VLED (50 V/div), CH4: ILED (0.5 A/div).