 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| DN74 ZXSC400 Photoflash LED reference design Description This design note shows the ZXSC400 driving a Photoflash LED. The input voltage is 3V with a maximum pulsed output current of 1A for 2ms. A typical schematic diagram is shown in Figure 1. C3 L1 U2 SW2 SW1 VBATT U1 VCC STDN GND VDRIVE ISENSE VFB C2 R2 C1 ZXSC400 R3 R1 R4 Charging mode: SW1 closed, SW2 open Discharging mode: SW1 open, SW2 closed Figure 1 Schematic diagram Operation In charging mode, SW1 is closed and SW2 is open the ZXSC400 is configured as a typical boost converter, charging capacitor C2 up the regulated output voltage set by the ratio of R1 and R2. This is typically 16V. The peak current of the converter (current drawn from the battery) is controlled by R3 plus R4, and is typically 280mA for this application. When C2 is charged to 16V the SW1 is opened and SW2 is closed, converting the ZXSC400 to a step down converter to provide a 1A constant current for 2ms to the photoflash LED. During step down operation, current flows from C2, through the photoflash LED, L1, U2 and is returned to C2 through R3. This means that the peak current is set at a higher value than in charging mode, typically 1A. When the current reaches it's peak value, U2 is switched off and current flows from L1 through the Schottky diode in U2, to the photoflash LED. This cyclic process is repeated until C2 is discharged. Issue 2 - July 2006 (c) Zetex Semiconductors plc 2006 1 www.zetex.com DN74 Ref U1 U2 L1 R1 R2 R3 R4 C1 C2 C3 12 H 10k 510k 22m 100m 1F 150 F 1F Value Part number ZXSC400E6 ZX3CDBS1M832 Generic Generic Generic Generic Generic Generic Generic Generic Table 1 Manufacturer Zetex Zetex Generic Generic Generic Generic Generic Generic Generic Generic Bill of materials Comments LED Driver in SOT23-6 Dual NPN and Schottky ISAT=1A 0805 size 0805 size 0805 size 0805 size www.zetex.com 2 Issue 2 - July 2006 (c) Zetex Semiconductors plc 2006 DN74 Typical operating waveforms (For typical application circuit where VBATT = 3V and Tamb = 25C unless otherwise stated) Figure 2 Performance graphs Issue 2 - July 2006 (c) Zetex Semiconductors plc 2006 3 www.zetex.com DN74 Intentionally left blank Europe Zetex GmbH Streitfeldstrae 19 D-81673 Munchen Germany Telefon: (49) 89 45 49 49 0 Fax: (49) 89 45 49 49 49 europe.sales@zetex.com Americas Zetex Inc 700 Veterans Memorial Highway Hauppauge, NY 11788 USA Telephone: (1) 631 360 2222 Fax: (1) 631 360 8222 usa.sales@zetex.com Asia Pacific Zetex (Asia Ltd) 3701-04 Metroplaza Tower 1 Hing Fong Road, Kwai Fong Hong Kong Telephone: (852) 26100 611 Fax: (852) 24250 494 asia.sales@zetex.com Corporate Headquarters Zetex Semiconductors plc Zetex Technology Park, Chadderton Oldham, OL9 9LL United Kingdom Telephone: (44) 161 622 4444 Fax: (44) 161 622 4446 hq@zetex.com 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 (c) Zetex Semiconductors plc 2006 |
Price & Availability of ZXSC40006
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |