MAX8595X/MAX8596X 19-3485 Rev 2 7/06 High-Efficiency, 36V Step-Up Converters with T Derating Option for 2 to 9 White LEDs A General Description Features Up to Nine LEDs at 25mA The MAX8595X/MAX8596X drive up to nine white LEDs with constant current and high efficiency to provide Temperature Derating Function to Allow Fewer LCD backlighting in cell phones, PDAs, and other LEDs for Same Light (MAX8596X) handheld devices. The series connection allows the 86% Efficiency (P / P ) LEDs IN LED currents to be identical for uniform brightness and 1.7% Current-Regulation Accuracy minimizes the number of traces to the LEDs. The MAX8595X regulates constant LED current over the Output Overvoltage Protection entire temperature range. The MAX8596X features an Flexible Dimming Control ambient-temperature derating function to avoid over- Analog driving the white LEDs during high ambient tempera- Direct-PWM Internal Filter tures, enabling higher drive current below +42C. 1MHz PWM Switching Frequency A single Dual Mode input provides a simple means of 0.1F Output Capacitor brightness adjustment and on/off control. Fast 1MHz 12mV Low Input Ripple P-P current-mode PWM operation allows for small input and Soft-Start Eliminates Inrush Current output capacitors and a small inductor while minimizing ripple on the input supply/battery. Soft-start eliminates 2.6V to 6V Input Range inrush current during startup. 0.3A Shutdown Current The MAX8595X/MAX8596X are available in a space- Pin Compatible with the MAX1561 and MAX1599 saving, 8-pin, 3mm x 3mm TDFN package. TDFN 3mm x 3mm x 0.8mm Package with Exposed Paddle Applications Cell Phones and Smart Phones Ordering Information PDAs, Palmtops, and Wireless Handhelds PIN- PKG e-Books and Subnotebooks PART TEMP RANGE PACKAGE CODE White LED Display Backlighting 8 TDFN-EP* MAX8595XETA-T -40C to +85C T833-1 MAX8595XETA+T -40C to +85C 8 TDFN-EP* T833-1 MAX8596XETA-T -40C to +85C 8 TDFN-EP* T833-1 MAX8596XETA+T -40C to +85C 8 TDFN-EP* T833-1 +Denotes lead-free package. T = Tape and reel. Dual Mode is a trademark of Maxim Integrated Products, Inc. *EP = Exposed paddle. Pin Configuration Typical Operating Circuit OUTPUT INPUT TOP VIEW UP TO 38V 2.6V TO 6V 2.2F 8 76 5 IN LX MAX8595X OUT ANALOG OR MAX8596X PWM DIMMING MAX8595X 0.1F MAX8596X CTRL PGND 1 2 3 4 200Hz TO 200kHz COMP CS GND TDFN 3mm x 3mm x 0.8mm A SIGN WILL REPLACE THE FIRST 2 TO 9 LEDs PIN INDICATOR ON LEAD-FREE PACKAGES. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE OUT LX IN PGND CTRL GND COMP CSHigh-Efficiency, 36V Step-Up Converters with T Derating Option for 2 to 9 White LEDs A ABSOLUTE MAXIMUM RATINGS IN to GND.................................................................-0.3V to +7V CS to GND ...................................................-0.3V to (V + 1.2V) IN PGND to GND .......................................................-0.3V to +0.3V Continuous Power Dissipation (T = +70C) A LX, OUT to GND.....................................................-0.3V to +40V 8-Pin TDFN 3mm x 3mm CTRL to GND...................-0.3V to the lower of +6V or (V + 2V) (derate 24.4mW/C above +70C)............................ 1950mW IN COMP ..........................................................-0.3V to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C IN I ...................................................................................1.0A Junction Temperature......................................................+150C LX RMS I ........................................................25mA (V < V + 1.2V) Storage Temperature Range .............................-65C to +150C CS CS IN Lead Temperature (soldering, 10s) .................................+300C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = 3.0V, L = 22H, C = 2.2F, C = 0.1F, C = 0.1F, R = 13 , V = 1.5V, T = -40C to +85C, unless other- IN IN OUT COMP SENSE CTRL A wise noted. Typical values are at T = +25C.) (Note 1) A PARAMETER CONDITIONS MIN TYP MAX UNITS Supply Voltage 2.6 6.0 V UVLO Threshold V rising or falling 2.10 2.38 2.55 V IN UVLO Hysteresis 30 mV Quiescent Current No switching 0.5 0.7 mA T = +25C 0.3 2 CTRL = GND, A Shutdown Supply Current A V = V OUT IN T = +85C1 A OVLO Threshold V rising 36 38 40 V OUT OVLO Hysteresis 2V V = 32V, V > 0.24V 9 20 35 OUT CTRL OUT Input Bias Current A T = +25C 0.01 1 A OUT = IN, CTRL = GND T = +85C 0.1 A V - IN Output Voltage Range (Note 2) 36 V V D ERROR AMPLIFIER T = +25C 0.295 0.300 0.305 A V = 1.50V, CTRL CTRL to CS Regulation T = 0C to +85C 0.292 0.300 0.308 V A V = 2.6V to 5.5V IN T = -40C to +85C 0.290 0.300 0.310 A T = +25C 0.01 1 A CS Input Bias Current V = V / 5 A CS CTRL T = +85C 0.03 A MAX8595X, V = 3.0V 310 330 347 CTRL T = -40C to +25C 330 345 360 CS Maximum Brightness Clamp A mV MAX8596X, Voltage T = +42C 343 A V = 3.0V CTRL T = +85C 106.5 A MAX8595Z 1.65 CTRL Voltage for CS Maximum V Brightness Clamp MAX8596Z 1.72 CS Derating Function Start MAX8596Z, V = 3.0V +42 C CTRL Temperature 2 MAX8595X/MAX8596X