SP1820 Four Channels Constant Current LED Driver DESCRIPTION The SP1820 is a four channels constant current driver white LED. The device can drive up to 20mA load current per channel from single cell Lithium Ion battery. SP1820 can provide lowest cost LED driver for various applications. It does not require any external components. Internal thermal protection automatically adjusts LED current to prevent overheating. APPLICATIONS z Battery Powered Devices z Digital Camera z PDA, MP3/4 z GPS z Mobile Phone z Keyboard/Display Backlight The dimming control can be achieved by feeding a PWM or analog signal into the Iset pin. The device can be shut down by Enable low. FEATURES z Low Cost LED Driver z Constant Current Output z Four Channels LED Driver Provides Matching LED Current z Low Quiescent Current z Disconnects LEDs in Shutdown Mode z Thermal Shut Down Protection z Current Adjustable via external resistor z Dimming Control thru either Enable or Iset PIN CONFIGURATION(SOP – 8P) PART MARKING 2009/04/20 Ver.2 Page 1 SP1820 Four Channels Constant Current LED Driver TYPICAL APPLCATION CIRCUIT PIN DESCRIPTION Pin 1 2 3 4 5 6 7 8 Symbol VCC GND EN ISET LED1 LED2 LED3 LED4 Description Supply Voltage Input Ground High Enable Pin Current Set Input LED 1 LED 2 LED 3 LED 4 ORDERING INFORMATION Part Number Package SP1820S8RGB SOP- 8P Part Marking SP1820 ※ SP1820S8RGB : 13” Tape Reel ; Pb – Free ; Halogen – Free 2009/04/20 Ver.2 Page 2 SP1820 Four Channels Constant Current LED Driver BLOCK DIAGRAM ABSOULTE MAXIMUM RATINGS (TA=25℃ Unless otherwise specified) Parameter DC Supply Voltage Output LED Current Symbol VIN ILED Operating Temperature Maximum Junction Temperature Storage Temperature TOPR TJ(Max) TS Value 5.5 20 -40～85 125 -65～150 Unit V mA ℃ ℃ ℃ The IC has a protection circuit against static electricity. Do not apply high static electricity or high voltage that exceeds the performance of the protection circuit to the IC. ELECTRICAL CHARACTERISTICS (TA=25℃, VIN=3.6V, RSET=7.5KOhm, VLED=0.5V, Unless otherwise specified) Parameter Operating Voltage LED Current Current Matching CH to CH Quiescent Current Line Regulation Load Regulation ISET Voltage Enable Voltage High Enable Voltage Low Thermal Shutdown Threshold Thermal Shutdown Hysteresis Current Off Mode 2009/04/20 Ver.2 Conditions Min. 2.7 18.5 ILED = 0A, Rset = Open ILED Change Per Volt Vcc Change VLED<5V, ILED = 20mA 3.6V≤Vin≤4.2V 3.6V≤Vin≤4.2V Typ. Max. 5.5 20 21.5 +/-1.5 +/-3.5 250 0.15 0.6 3 6 1.5 3.6 0.4 130 20 0.2 Unit V mA % μA %/V %/V V V V ℃ ℃ μA Page 3 SP1820 Four Channels Constant Current LED Driver PERFORMANCE CHARACTERISTICS (TA=25℃, unless otherwise specified.) ILED vs. Power Supply ILED vs. VLED 20 18 16 IL E D ( m A ) IL E D ( m A ) 14 12 10 8 6 4 2 0 0 0.2 0.4 VLED(V) 0.6 0.8 20 18 16 14 12 10 8 6 4 2 0 3.6 1 3.8 4 4.6 4.8 5 28 32 LED Current vs. Set Resister Quiescent Current vs. Power Supply 30 125 25 IL E D ( m A ) 120 Iq (u A ) 4.2 4.4 P owe r S upply(V) 115 110 20 15 10 5 105 0 100 8 3.6 2009/04/20 3.8 4 Ver.2 4.2 4.4 P owe r S upply(V) 4.6 4.8 5 12 16 20 24 Rs e t(KΩ ) Page 4 SP1820 Four Channels Constant Current LED Driver APPLICATION INFORMATION CIRCUIT DESCRIPTION SP1820 is a four channels white-LED driver with matching current output. The matching current regulator has a 460:1 ratio between ILED and ISET. SP1820 is capable to supply 25mA for each channel with proper selection of external resistor. The design has a band gap regulator, voltage to current converter and mirror drivers. THERMAL PROTECTION SP1820 has a thermal comparator to shut down the device when the internal temperature reaches 150℃. It will remain shut down until the temperature drops to 130℃. ENABLE SP1820 has an enable pin that is designed for TTL input. The device will be active at voltage high. This pin can also be used to control the brightness of LED with a PWM signal. The brightness is proportional to the duty cycle of the PWM signal. When duty cycle is zero, LEDs are turned off. For 50% duty cycle, it will result an average ILED to be half the programmed LED current which is set by RSET. ISET The ISET Pin is a voltage input to set the current of LED. An external resistor is used to set the output current, as approximated with the following equation: RSET = 460 * (1.2V/ILED) However, the RSET shall not be selected to exceed the maximum current delivery capability of the device, 25mA. A PWM signal or analog signal can also be applied at ISET pin to control the LED brightness. 2009/04/20 Ver.2 Page 5 SP1820 Four Channels Constant Current LED Driver SOP- 8 PACKAGE OUTLINE 2009/04/20 Ver.2 Page 6 SP1820 Four Channels Constant Current LED Driver Information provided is alleged to be exact and consistent. SYNC Power Corporation presumes no responsibility for the penalties of use of such information or for any violation of patents or other rights of third parties which may result from its use. No license is granted by allegation or otherwise under any patent or patent rights of SYNC Power Corporation. Conditions mentioned in this publication are subject to change without notice. This publication surpasses and replaces all information previously supplied. SYNC Power Corporation products are not authorized for use as critical components in life support devices or systems without express written approval of SYNC Power Corporation. ©The SYNC Power logo is a registered trademark of SYNC Power Corporation ©2004 SYNC Power Corporation – Printed in Taiwan – All Rights Reserved SYNC Power Corporation 7F-2, No.3-1, Park Street NanKang District (NKSP), Taipei, Taiwan 115 Phone: 886-2-2655-8178 Fax: 886-2-2655-8468 http://www.syncpower.com 2009/04/20 Ver.2 Page 7