IS31LT3910 T8 Evaluation Board Guide Description Quick Start The IS31LT3910 is a peak current mode control LED driver IC. The IS31LT3910 operates in constant off-time mode. It allows efficient operation of High Brightness (HB) LEDs with voltage sources ranging from 8VDC to 450VDC or 110VAC/220VAC. The IS31LT3910 includes a PWM dimming input that can accept an external control signal with a duty ratio of 0 100% and a frequency of up to a few kilohertz. It also includes a 50 - 240mV linear dimming input which can be used either for linear dimming or for temperature compensation of the LED current. The IS31LT3910 is ideally suited for buck LED drivers. Since the IS31LT3910 operates in peak current mode control, the controller achieves good output current regulation without the need for any loop compensation. It achieves good PWM dimming response because the response time is limited only by the rate of rise and fall of the inductor current, enabling very fast rise and fall time. Recommended Equipment 90~240VAC/50~60Hz power supply LEDs (12 in series and 24 in parallel) Multimeter Features Caution: Do not turn on the power supply until all connections are completed. Wide input range from 8VDC to 450VDC or 110VAC/220 VAC Temperature compensation to regulate LED current Application from a few mA to more than 1A output Constant off-time operation Linear and PWM dimming capability Requires few external components for operation Applications DC/DC or AC/DC LED driver applications General purpose constant current source Signal and decorative LED lighting Absolute Maximum Ratings ≤ 265VAC power supply ≤ 42V Vout (Total Vf) Caution: Do not exceed the conditions listed above, otherwise the board will be damaged or the output will be limited. Procedure The IS31LT3910 Evaluation Board is fully assembled and tested. Follow the steps listed below to verify board operation. 1) Connect the positive terminal of the LEDs to the LED+ pin of the DEMO and the negative terminal of the LEDs to the LED- pin of the DEMO. 2) Connect the input pins (L and N) of the DEMO to AC power supply. Turn on the power supply. 3) Backlighting LED driver Ordering Information PART # TEMP RANGE IC PACKAGE IS31LT3910_GRLS2_EBT8 -40 °C to 85°C SOP-8 (5.0 x 6.0mm) For pricing, delivery, and ordering information, please contact ISSI at [email protected] or call +1-408-969-6600 Integrated Silicon Solution, Inc. – www.issi.com R1.0, 08/26/2011 1 IS31LT3910 T8 Evaluation Board Guide IS31LT3910 Figure 1. IS31LT3910 Evaluation Board Schematic Figure 2. Picture of Evaluation Board NOTE: Physical dimensions are (L x W x H): 28.1mm x 17mm x 12mm Figure 3. PCB Layout- Top Layer Figure 4. PCB Layout- Bottom Layer Line Regulation Rate and Efficiency Input Voltage Input Power PF Output Voltage Output Current Efficiency AC：90V 18.45W 0.851 38.42V 0.416A 86.63% AC：110V 18.39W 0.886 38.42V 0.420A 87.75% AC：130V 18.31W 0.873 38.39V 0.420A 88.06% AC：180V 18.37W 0.826 38.37V 0.422A 88.14% AC：220V 18.57W 0.809 38.35V 0.422A 87.15% AC：240V 18.68W 0.801 38.32V 0.422A 86.57% Integrated Silicon Solution, Inc. – www.issi.com R1.0, 08/26/2011 2 IS31LT3910 T8 Evaluation Board Guide Bill of Materials No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Name X Capacitor Film Capacitor AL Capacitor AL Capacitor SMD Capacitor SMD Capacitor SMD Capacitor Inductor EE Inductor SMD Inductor Zener Diode Zener Diode FR Diode FR Diode Opto-coupler N-MOSFET Fuse IC Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Description 0.1uF,275V 10nF,630V 33uF,100V 22uF,250V 10uF,25V,0805,X7R 1uF,25V,0805,X7R 390pF,25V,0805,X7R 3mH,10%,8*10,Isat＞100mA 0.65mH,Isat≥800mA 10 uH,Isat≥800mA 6.5V,5% 39V,5% 1A,600V,ESIJ,SMA 1N4148 P521GB 4N60,4A,600V,TO-220 1A,250V,3*10 IS31LT3910,SOP-8 4.7Ω,1W,1% 4.7Ω,1W,1% 220KΩ,1W,1% 150KΩ,0805,1% 4.7KΩ,0805,1% 0.47Ω,0805,1% 10Ω,0805,1% 33Ω,0805,1% 100Ω,0805,1% 1KΩ,0805,1% 30K,0805,1% Ref Des. C1, C1.1 C2 C7 C3, C4 C5 C8 C6 L3, L3.1 L5, L6 L4 DZ1 DZ2 D8, D9 D10 IC2 Q1 Fuse IC1 R11 R12 R4, R5 R6 R1, R2 R9, R10 R7 R8 R16 R15 R13 Qty. 2 1 1 2 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 2 1 2 2 2 2 2 2 1 MFR P/N Integrated Silicon Solution, Inc. – www.issi.com R1.0, 08/26/2011 3 IS31LT3910 T8 Evaluation Board Guide EMI test Integrated Silicon Solution, Inc. – www.issi.com R1.0, 08/26/2011 4 IS31LT3910 T8 Evaluation Board Guide Copyright © 2011 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products. Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that: a.) the risk of injury or damage has been minimized; b.) the user assume all such risks; and c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstance Integrated Silicon Solution, Inc. – www.issi.com R1.0, 08/26/2011 5