EUP2595JIR1

EUP2595 32V Step-Up Converters for Two to Nine White LEDs DESCRIPTION The EUP2595 is a constant current step-up converter specially designed for driving white LEDs. The step-up converter topology allows series connection of the white LEDs so the LED currents are identical for uniform brightness. The EUP2595 can drive 9 LEDs in series. The brightness of the LEDs can be adjusted through a voltage level on the CTRL pin or by applying a PWM signal to CRTL pin. 1MHz current-mode, pulse-width modulated (PWM) operation allows for small input and output capacitors and a small inductor while minimizing ripple on the input supply/battery. Programmable soft-start eliminates inrush current during startup. The EUP2595 is available in a space-saving, 8-pin 3mm x 3mm TDFN package. FEATURES 2.6V to 5.5V Input Range 32V (max) Output with Overvoltage Protection Up to 90% Efficiency Flexible Analog or PWM Dimming Control Internal High Power MOSFET Switch < 1µA shutdown Current Fast 1MHz PWM Operation Small, Low-Profile Inductors and Capacitors 3mm × 3mm TDFN-8 Package RoHS Compliant and 100% Lead (Pb)-Free APPLICATIONS Cell Phones and Smart Phones PDAs, Palmtops, and Wireless Handhelds e-Books and Subnotebooks White LED Display Backlighting Typical Application Circuit Figure 1. Typical Application Circuit DS2595 Ver1.1 Aug. 2008 1 EUP2595 Pin Configurations Package Type Pin Configurations TDFN-8 Pin Description PIN OUT IN CTRL CS COMP GND PGND LX Pin 1 2 3 4 5 6 7 8 DESCRIPTION WLED output overvoltage sense pin. Add a 1kΩ resistor to improve overvoltage sense accuracy. Input Supply Voltage. Brightness Control Input. LED brightness is controlled by the voltage applied to CTRL. Varying the voltage from 0.24V to 1.65V adjusts the brightness from dim to bright, respectively. Any voltage above 1.65V does not increase brightness. Current-Sense Feedback Input. Connect a resistor from CS to GND to set the LED bias current. The voltage at CS regulates to VCTRL / 5 or 0.330V, whichever is lower. Compensation Input. Connect a 0.1µF capacitor (CCOMP) from COMP to GND. CCOMP stabilizes the converter and controls soft-start. CCOMP discharges to GND when in shutdown. Common Ground. Connect to PGND and the exposed pad directly under the IC. Power Ground. Connect to GND and the exposed pad directly under the IC. Inductor Connection. This pin is high impedance during shutdown. DS2595 Ver1.1 Aug. 2008 2 EUP2595 Ordering Information Order Number EUP2595JIR1 Package Type TDFN-8 Marking Operating Temperature Range -40 °C to 85°C xxxxx 2595A EUP2595 □ □□ □ Lead Free Code 1: Lead Free 0: Lead Packing R: Tape & Reel Operating temperature range I: Industry Standard Package Type J: TDFN-8 Block Diagram Figure 2. DS2595 Ver1.1 Aug. 2008 3 EUP2595 Absolute Maximum Ratings IN to GND -------------------------------------------------------------------------- -0.3V to 6V PGND to GND ---------------------------------------------------------------------- -0.3V to 0.3V LX,OUT to GND ------------------------------------------------------------------- -0.3V to 35V CTRL to GND -------------------------------------- -0.3V to the lower of 6V or (VIN +0.5V) COMP,CS to GND ---------------------------------------------------------- -0.3V to (VIN +0.3V) ILX ------------------------------------------------------------------------------------- 1A Thermal Resistance TDFN-8 -------------------------------------------------------------------------------- 50°C /W Junction Temperature ---------------------------------------------------------------- 150°C Storage Temperature Range ------------------------------------------------------ -65°C to 150°C Lead Temperature (Soldering, 10sec.) --------------------------------------------- 260°C Recommended Operating Conditions Supply Voltage, VIN ---------------------------------------------------------------- 2.6V to 5.5V Operating Temperature Rang ----------------------------------------------------- -40°C to 85°C Electrical Characteristics (VIN = 3V, Lin = 22µH, CIN = 2.2µ, COUT = 0.1µ, CCOMP = 0.1µF, RSENSE = 13Ω, VCTRL = 1.5V, TA =-40°C to +85°C, unless otherwise noted. Typical values are at TA =25°C.) Parameter Supply Voltage UVLO Threshold UVLO Hysteresis Quiescent Current Shutdown Supply Current OVLO Threshold OVLO Hysteresis OUT Input Bias Current Output Voltage Range ERROR AMPLIFIER CTRL to CS Regulation CS Input Bias Current CTRL Input Resistance CTRL Dual-Mode Threshold CS Maximum Brightness Clamp Voltage COMP Input Resistance to Ground VIN Rising Conditions Min 2.6 2.23 2.20 EUP2595 Typ Max. 5.5 2.40 2.35 30 350 2.60 2.55 700 1.50 35 32.8 25 1 32 300 530 190 330 23.3 310 1 850 245 347 35 Unit V V mV µA µA V V µA V mV µA kΩ mV mV kΩ VIN Falling No Switching, VCTRL=VCS=1V VOUT1=V+, EN1=EN2=GND Rising Falling VOUT=32V,VCTRL> 0.24V VOUT=VIN, CTRL=GND 32 30 0.15 33.5 31.3 2.20 15 VIN-VD VCTRL = 1.5V, VIN= 2.6V to 5.5V VCS = VCTRL/5 0