XC9116 Series ETR0407-005 Step-Up DC/DC Converter-Backlight LED Driver GENERAL DESCRIPTION The XC9116 series is a fixed frequency, constant current step-up DC/DC converter ideal for driving LEDs used in backlighting applications such as cellular phones, PDAs and digital cameras. Output voltage of up to 17.5V can be derived, therefore four white LEDs in series can be driven. Since an LED current can be set by an external resistor when LEDs are in-series connection, all white LEDs can be turned on equably. A network of two parallel legs with three in each LED can be also driven. Luminance of the LEDs is controlled by changing the duty cycle of a PWM signal applied to the CE pin. Efficiency is high with the low feedback reference voltage ensuring the RLED losses are minimal. In addition, an internal MOSFET with an RDSON of 2.0 is used. A low profile and small board area solution can be achieved using a chip coil and an ultra small ceramic output capacitor (CL) of 0.22F as a result of the high 1.0MHz switching frequency. The B type of XC9116 has an additional fault detection circuit. If the LEDs are disconnected or damaged, excess or run away output voltage is prevented by stopping the drive of the internal MOSFET. APPLICATIONS FEATURES Input Voltage Range : 2.5V ~ 6.0V For White LED drivers Output Voltage Range : Up to 17.5V externally set-up Mobile phones, PHS : Reference voltage 0.2V +5% PDAs Oscillation Frequency : 1.0MHz, 20% ON Resistance : 2.0 Digital still cameras Efficiency : 86% (XC9116B Type) : 84% (XC9116D Type) (VIN=3.6V, ILED=20mA when driving 3 white LEDs in series) Control : PWM control Standby current : ISTB=1.0A (MAX.) Load Capacitor : 0.22F, ceramic Lx Limit Current : 325mA Lx Overvoltage Limit : XC9116B series No Lx Overvoltage Limit : XC9116D series Package : SOT-25, USP-6B Environmentally Friendly : EU RoHS Compliant, Pb Free TYPICAL PERFORMANCE TYPICAL APPLICATION CIRCUIT CHARACTERISTICS XC9116B Type 1/22 XC9116 Series PIN CONFIGURATION 6 1 5 2 *The dissipation pad of the USP-6B package 3 4 should be left open. If the circuit needs to be connected to other pin, it should be connected to the VSS pin. SOT-25 (TOP VIEW) USP-6B (BOTTOM VIEW) PIN ASSIGNMENT PIN NUMBER PIN NAME FUNCTION SOT-25 USP-6B 1 2 Lx Switch 2 3 VSS Ground 3 1 FB Voltage Feedback 4 6 CE Chip Enable 5 4 VIN Power Input - 5 NC No Connection CE PIN FUNCTION CE PIN OPERATIONAL STATE H Operation L Shut-down PRODUCT CLASSIFICATION Ordering Information *1 ( ) XC9116- DESIGNATOR DESCRIPTION SYMBOL DESCRIPTION B Available Lx Overvoltage Limit D Not available FB Voltage 02 0.2V Oscillation Frequency A 1MHz MR SOT-25 Packages - DR-G USP-6B (*2) Taping Type DR USP-6B (*1) The -G suffix indicates that the products are Halogen and Antimony free as well as being fully RoHS compliant. (*2) The device orientation is fixed in its embossed tape pocket. For reverse orientation, please contact your local Torex sales office or representative. (Standard orientation: R-, Reverse orientation: L-) 2/22