RT7304 Evaluate Report for Bulb Internal Power (Flyback) ACDC BU / SLM Division Feb . 2016 http://www.richtek.com/LED CONFIDENTIAL CONFIDENTIAL RT7304 Brief introduction RT7304 is an active power factor correction controller specifically designed for using as a constant current LED driver. Supporting: Isolation: PSR mode Non-isolation: Buck-Boost mode Applications AC/DC LED lighting driver ……… 2 CONFIDENTIAL CONFIDENTIAL RT7304 Features Primary-Side Regulation PWM Controller and High PF LED Driver • Primary Side Regulation (PSR) • Power Factor Correction (PFC) • Critical conduction Mode (CRM) • Max/Min Switch Frequency Clamping • Max/Min on Time Limitation 3 CONFIDENTIAL CONFIDENTIAL RT7304 Advantage • Universal input voltage. (90Vac~264Vac) • Good LED current regulation. • No shunt regulator and photo to achieve the 2 nd regulation. • Protection: a. Open-circuit protection b. Short-circuit protection c. Output diode short-circuit protection d. VDD under/over voltage protection e. Over temperature protection f . Cycle-by-cycle current limitation g. Excellent PF and THD. 4 CONFIDENTIAL CONFIDENTIAL Circuit 5 CONFIDENTIAL CONFIDENTIAL Electrical Performance 6 CONFIDENTIAL CONFIDENTIAL Efficiency 7 CONFIDENTIAL CONFIDENTIAL Power Factor 8 Copyright © 2015 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. CONFIDENTIAL CONFIDENTIAL Current regulation Limit in 2.82% 9 CONFIDENTIAL CONFIDENTIAL Load regulation Frequency Vac [V] Vout [V] Iout [mA] 60Hz 110 41.49 178 60Hz 110 44.53 177 60Hz 110 47.70 177 50Hz 230 41.62 181 50Hz 230 44.75 180 50Hz 230 47.69 179 Load regulation 0.56% 1.10% 10 CONFIDENTIAL CONFIDENTIAL PCB layout Top Trace Bottom Trace 11 CONFIDENTIAL CONFIDENTIAL Demo board photo Length Width Height 47mm 25mm 18mm PCB No : PCB024_V1 12 CONFIDENTIAL CONFIDENTIAL BOM Item Location Value Type 1 F1 1A/250V SS-5F-2P 2 LX1 5.5mH DR0612 3 LX2 5.5mH DR0612 4 T1 Lm=1950uH EE-16 5 BD1 TB6S DB-TB6S 6 D1 1N4148 SOD-323 7 D2 FFM-107-M SOD-123 8 D3 GS1M SMA 9 D4 ES2G SMB 10 IC1 RT7304 SOT-23-6 11 Q1 04N65 TO-251 12 R1 300KΩ 1206 13 CONFIDENTIAL CONFIDENTIAL BOM Item Location Value Type 13 R2 300KΩ 1206 14 R3 150Ω 0805 15 R4 3Ω 1206 16 R4A 3.3Ω 1206 17 R5 3KΩ DIP 18 R6 43KΩ 0805 19 R7 8.2KΩ 0805 20 R8 10Ω 0805 21 R9 150KΩ 1206 22 R11 47Ω 1206 23 R12 200KΩ 1206 24 RX1 20KΩ 1206 14 CONFIDENTIAL CONFIDENTIAL BOM Item Location Value Type 25 RX2 20KΩ 1206 26 R10 100Ω 1206 27 CX1 0.047uF/275V 12.5X6-10MM 28 C1 0.1uF/275V CAP-3X10MM 29 C3 2.2uF/10V 0805 30 C5 2.2nF/1KV 1206 31 C6 100pF/1KV 1206 32 C7 1nF/250Vac DIP 33 EC1 10uF/50V EC-5X11 34 EC2 100uF/63V EC-8X20 Total : 34 pcs 15 CONFIDENTIAL CONFIDENTIAL Optional component Item Location Value Type 1 VR1 7N471K DIP Total : 1 pcs 16 CONFIDENTIAL CONFIDENTIAL Transformer CONFIDENTIAL CONFIDENTIAL Power Component Stress Voltage Test condition: 90Vac input / 45V,178mA output Stead state Location Max rating (V) Measure De-rating Q1 650 300 46.15% D1 400 139 34.75% Transient State Location Max rating (V) Measure De-rating Q1 650 300 46.15% D1 400 139 34.75% 18 CONFIDENTIAL CONFIDENTIAL Power Component Stress Voltage Test condition: 264Vac input / 45V,178mA output Stead state Location Max rating (V) Measure De-rating Q1 650 560 86.15% D1 400 320 80.00% Transient State Location Max rating (V) Measure De-rating Q1 650 564 86.77% D1 400 324 81.00% 19 CONFIDENTIAL CONFIDENTIAL LED open protection Vac_in = 90V Ch2:Vout ; Ch3:Vzcd ; Ch4:Vdd Vac_in = 264V Ch2:Vout ; Ch3:Vzcd ; Ch4:Vdd When LED open , the output keeps rising and causing the VZCD rising accordingly. If Vzcd trigger the protected level(2.9V~3.3V), the IC latch down. IC will be auto-restarted when the output is recovered. 20 CONFIDENTIAL CONFIDENTIAL LED Short protection Vac_in = 90V Ch2:Vout ; Ch3:Vgate ; Ch4:Vcs Vac_in = 264V Ch2:Vout ; Ch3:Vgate ; Ch4:Vcs When LED short , the output level is 0V and the Vcs will rise to trigger the protected function. IC will be auto-restarted when the output is recovered. 21 CONFIDENTIAL CONFIDENTIAL Harmonic(IEC61000-3-2) 110V input Class C : Pass Class D : Pass 22 CONFIDENTIAL CONFIDENTIAL Harmonic(IEC61000-3-2) 230V input Class C : Pass Class D : Pass 23 CONFIDENTIAL CONFIDENTIAL Conduction-EMI (230V-LPass) 24 CONFIDENTIAL CONFIDENTIAL Conduction-EMI (230V-NPass) 25 CONFIDENTIAL CONFIDENTIAL Conduction-EMI (110V-LPass) 26 CONFIDENTIAL CONFIDENTIAL Conduction-EMI (110V-NPass) 27 CONFIDENTIAL CONFIDENTIAL Radiation-EMI 230V-V Pass 230V-H Pass 28 CONFIDENTIAL CONFIDENTIAL Radiation-EMI 110V-V Pass 110V-H Pass 29