ZXLD1371EV5 EVALUATION BOARD USER GUIDE DESCRIPTION The ZXLD1371EV5, Figure 1, is an evaluation board for the ZXLD1371EV5 LED driver chip. The board is in a Buck-Boost configuration with an input voltage range of 5.4-30 VDC and will drive a string of up to 5 LEDs. It is set for an output current of 680mA and offers convenient connections for external control inputs and monitoring. + 5.4-30V DC 1-5 LEDS Figure 1: ZXLD1371EV5 evaluation board and connection diagram QUICK START 1) Connect 12V DC supply across Vin and GND points (observe correct polarity). 2) Connect LED string across LED A and LED K points (observe correct polarity). LED current is set at 680mA, so ensure LED string is capable of this current. 3) Cover LED string or wear eye protection. Do not look directly at LEDs in use. 4) Switch on DC power supply. ZXLD1371EV5 Connection Point Definition Name Description Vin Positive supply voltage. 5.4 to 30V GND Supply Ground (0V). തതതതതതതത External PWM dimming input (note that this input is inverted) PWM ADJ External DC dimming input (Remove R8 for DC Dimming) TADJ External thermal dimming input (NTC to GND) VAUX VAUX monitoring point FLAG FLAG pin monitoring point STATUS STATUS pin monitoring point LX LX monitoring point LED K LED Cathode connection LED A LED Anode connection Issue 1 – February 2012 © Diodes Incorporated, 2012 www.diodes.com ZXLD1371EV5 LED K VIN GND C6 2u2F 100V GND C7 2u2F 100V GND R1 0R15 R2 0R DO NOT FIT GND D2 R4 LX 100R R3 C2 1uF 100V DFLS140 D3 BZT52C51 C1 100nF R6 10k 1 R8 0R R9 270k REF 2 3 R7 1k8 4 12 U1 IC - ZXLD1371 D1 D GI GATE R5 10 0R ADJ REF STATUS TADJ SHP LX LX PDS5100 PWM FLAG SGND G 16 PAD 15 GI VIN VAUX PWM PWM Q1 G C11 2u2F 100V 5 GND GND 14 REF PWM 8 9 7 6 17 R10 68k C10 2u2F 100V S DMN6068LK3 GND GND C9 1uF 100V LEDA LX L1 33uH MSS1278 GND 11 GND D Q3 2N7002 S C8 1uF 100V ISM 2 0R15 VAUX 13 GND C5 2u2F 100V ISM GND C12 2u2F 100V NC NC 47uF DO NOT FIT 100V PGND C4 GND Q2 D R12 47k STATUS C3 330pF 2N7002 FLAG D4 BZT52C51 G S R11 2k ADJ GND GND GND GND TADJ Figure 2: ZXLD1371EV5 evaluation board Schematic ZXLD1371EV5 EVALUATION BOARD REFERENCE DESIGN The ZXLD1371EV5 is a Buck-Boost reference design, based around the ZXLD1371 lighting IC. The circuit will accept an input voltage from 5.4 to 30 VDC and can drive an output string of up to 5 LEDs at 680mA. The board has three control inputs and multiple signal monitoring points. തതതതതതതത input allows the user to input a PWM brightness signal. It is recommended to be The PWM between 100Hz and 500Hz for maximum LED current dynamic range. Note that the PCB includes a circuit that inverts the signal fed onto this input, in order that the input can be wire-ORed with the overvoltage protection circuit. The ADJ input allows for DC dimming input, with a voltage between 0.125V and 1.25V for full brightness. In order to use an external control on ADJ, R8 must be removed. The TADJ input is for connection of an external 10k NTC thermistor which will dim the LEDs as temperature increases, for maximizing LED lifetime. With a 10k NTC and R7 = 1.8kΩ, the thermal trip point will be around 70ºC. The VAUX monitoring point allows easy connection to the chip auxiliary power supply and measurement of the bootstrap circuit where used. It can also be used to feed in an external source of VAUX if R3 and R4 are removed. R4 connects VAUX to LX through D2 as a bootstrap circuit, allowing for operation at low Vin values (5-8V). If bootstrapping is not required, remove R4 and fit R3 = 0Ω. FLAG and STATUS monitoring points allow these outputs of the chip to be monitored. For further information on output information on these pins see the ZXLD1371 datasheet. The LX switching point can be monitored on the test point, in order to easily monitor the output PWM. The LED string load can be connected across the LED A and LED K points. In Buck-Boost configuration the switching voltage at LX is the sum of the input and load voltages, which can therefore approach 50V when driving up to 5 LEDs. Issue 1 – February 2012 www.diodes.com © Diodes Incorporated 2012 2 ZXLD1371EV5 ZXLD1371EV5 Component list QTY PCB IDENT VALUE DESCRIPTION 1 1 U1 Q1 ZXLD1371 DMN6068LK3 2 1 1 2 1 1 0 1 1 1 1 1 1 1 1 1 1 3 1 0 6 Q2, Q3 D1 D2 D3, D4 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 C1 C2, C8, C9 C3 C4 C5, C6, C7, C10, C11, C12 L1 2N7002 PDS5100 DFLS140 BZT52C51 0R15 0R12 DO NOT FIT 100R 0R0 10k 1k8 0R 270k 68k 2k 47k 100nF 1uF 330pF DO NOT FIT 2u2F TP1, TP2, TP3, TP4, TP5, TP6, TP7, TP8, TP9, TP10, TP11 Test Point TSSOP16EP LED driver IC – Diodes Zetex 60V N-Channel Enhancement Mode MOSFET – Diodes Inc. SOT23 FET - Diodes Zetex Freewheeling diode 5A, 100V – Diodes Inc. Schottky diode 1A, 40V – Diodes Inc. Zener, 51V 400mW SOD123 – Diodes Inc. Resistor 1206 1% thick film 250ppm generic Resistor 1206 1% thick film 250ppm generic Resistor 0805 Resistor 1206 1% thick film 250ppm generic Resistor 1206 1% thick film 250ppm generic Resistor 0805 1% thick film 250ppm generic Resistor 0805 1% thick film 250ppm generic Resistor 0805 1% thick film 250ppm generic Resistor 0805 1% thick film 250ppm generic Resistor 0805 1% thick film 250ppm generic Resistor 0805 1% thick film 250ppm generic Resistor 0805 1% thick film 250ppm generic Capacitor 0603, 100V X7R generic Capacitor 1206, 100V X7R generic Capacitor 0805, 100v C0G generic Electrolytic capacitor P5D10 Capacitor, 1812, 100V X7R generic Murata GRM43ER72A225KA01L Coilcraft MSS1278-333MLB NIC Components NPIS27H330MTRF 2.15mm dia. test loops, green, generic, Hughes 100-108 1 11 33uH Note: The component values and part numbers are correct at the time of publication. Diodes Inc. reserves the right to substitute other parts where necessary, without further notification. Issue 1 – February 2012 www.diodes.com © Diodes Incorporated 2012 3 ZXLD1371EV5 IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated website, harmless against all damages. Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channels. Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings noted herein may also be covered by one or more United States, international or foreign trademarks. LIFE SUPPORT Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device or system whose failure to perform can be reasonably be expected to cause the failure of the life support device or to affect its safety or effectiveness. Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. Copyright © 2011, Diodes Incorporated www.diodes.com Sales offices The Americas Europe Taiwan Shanghai Shenzhen Korea 3050 E. Hillcrest Drive Kustermannpark 7F, No. 50, Rm. 606, No.1158 Room A1103-04, 6 Floor, Changhwa B/D, Westlake Village, Balanstraße 59, Min Chuan Road Changning Road ANLIAN Plaza, #4018 1005-5 Yeongtong-dong, CA 91362-3154 Tel: (+1) 805 446 4800 D-81541 München Germany Hsin-Tien Taipei, Taiwan Shanghai, China Tel: (+86) 215 241 4882 Jintian Road Futian CBD, Yeongtong-gu, Suwon-si, Gyeonggi-do, Korea 443-813 Fax: (+1) 805 446 4850 Tel: (+49) 894 549 490 Tel: (+886) 289 146 000 Fax (+86) 215 241 4891 Shenzhen, China Tel: (+82) 312 731 884 Fax: (+49) 894 549 4949 Fax: (+886) 289 146 639 Tel: (+86) 755 882 849 88 Fax: (+86) 755 882 849 99 Fax: (+82) 312 731 885 Issue 1 – February 2012 www.diodes.com © Diodes Incorporated 2012 4