DN69 ZXSC310 Garden light reference design Description This design note shows a typical ZXSC310 LED driver circuit for a solar power garden light. The input voltage ranges from1.7V to 2.5V with a maximum output current of 160mA at 2.4V input. A typical schematic diagram is shown in Figure 1. L1 1.7V to 2.5V D1 U1 Q1 VCC VDRIVE C1 Stdn ISENSE Gnd ZXSC310 R1 Figure 1 Ref Value Schematic diagram Part number Manufacturer Contact details Comments U1 ZXSC310E5 Zetex www.zetex.com LED driver in SOT23-5 Q1 FMMT617 Zetex www.zetex.com Low sat NPN in SOT23 Zetex www.zetex.com 0.5A Schottky in SOT23 D1 500mA ZHCS500 L1 15H DO3316P-153 Coilcraft www.coilcraft.com ISAT =3A R1 70m⍀ Generic Generic NA C1 100F Generic Generic NA Table 1 Issue 2 - July 2006 © Zetex Semiconductors plc 2006 0805 size Bill of materials 1 www.zetex.com DN69 Total output current Table 2 shows the maximum available output current and the current per LED for a given number of LEDs. An LED forward voltage of 3.5V is assumed. Total LED Current (mA) 4 LEDs 5 LEDs 6 LEDs 176 44 35 29 163 41 33 27 153 38 31 25 141 35 28 23 131 33 26 22 119 30 24 20 110 27 22 18 97 24 19 16 89 22 18 15 80 20 16 13 70 18 14 12 61 15 12 10 Table 2 www.zetex.com Total output current 2 Issue 2 - July 2006 © Zetex Semiconductors plc 2006 DN69 Typical operating characteristics (For typical application circuit where Tamb = 25°C unless otherwise stated) Figure 2 Issue 2 - July 2006 © Zetex Semiconductors plc 2006 Performance graphs 3 www.zetex.com DN69 Intentionally left blank Europe Americas Asia Pacific Corporate Headquarters Zetex GmbH Streitfeldstraße 19 D-81673 München Germany Zetex Inc 700 Veterans Memorial Highway Hauppauge, NY 11788 USA Zetex (Asia Ltd) 3701-04 Metroplaza Tower 1 Hing Fong Road, Kwai Fong Hong Kong Zetex Semiconductors plc Zetex Technology Park, Chadderton Oldham, OL9 9LL United Kingdom Telefon: (49) 89 45 49 49 0 Fax: (49) 89 45 49 49 49 [email protected] Telephone: (1) 631 360 2222 Fax: (1) 631 360 8222 [email protected] Telephone: (852) 26100 611 Fax: (852) 24250 494 [email protected] Telephone: (44) 161 622 4444 Fax: (44) 161 622 4446 [email protected] For international sales offices visit www.zetex.com/offices Zetex products are distributed worldwide. For details, see www.zetex.com/salesnetwork This publication is issued to provide outline information only which (unless agreed by the company in writing) may not be used, applied or reproduced for any purpose or form part of any order or contact or be regarded as a representation relating to the products or services concerned. The company reserves the right to alter without notice the specification, design, price or conditions of supply of any product or service. www.zetex.com 4 Issue 2 - July 2006 © Zetex Semiconductors plc 2006