SC4509 Highly Integrated Step-Up Converter for White LED Applications in MLPD-W8-2x2 PPOOWWEERR MMAANNAAGGEEMMEENNTT Description Features The SC4509 is a highly integrated step-up DC/DC convert- (cid:139) V range: 2.7V — 10V IN er targeted for white LED backlighting applications. It is (cid:139) Integrated Schottky diode designed to drive up to fi ve LEDs with a wide input voltage (cid:139) 81% effi ciency range of 2.7 to 10 volts. Designed for 20V output voltage, (cid:139) Requires only 4 external components the SC4509 operates with a constant 1.2MHz PWM fre- (cid:139) Up to 20V of output voltage quency. To optimize effi ciency, the feedback voltage is set (cid:139) 30mA maximum LED current to only 199mV, minimizing the power loss in the current (cid:139) Open LED protection (OVP) setting resistor. The product requires only four external (cid:139) 1.2MHz PWM switching frequency components (CIN, COUT, L and R ), making it ideal for (cid:139) Low feedback voltage (20OmV typical) SET applications that require low cost and minimal PCB area. (cid:139) Wide range of PWM dimming (cid:139) Drives up to 5 LEDs The SC4509 offers current limit and over-voltage protec- (cid:139) 500mA switch current limit tion (OVP) to safeguard the device under extreme operat- (cid:139) 220nF output capacitor ing conditions. If the LEDs become disconnected or fail in (cid:139) Available in 2mm x 2mm x 0.75mm MLPD-W8 and an open state condition, OVP circuitry will be activated to SOT23-6 packages shut down the device. The EN/SS pin allows the device (cid:139) Packages are fully WEEE and RoHS compliant to be placed in power-down mode, disabling the control circuitry to reduce input current. Applications (cid:139) Digital Video Cameras (cid:139) White LED Backlight Driver (cid:139) OLED Display Driver (cid:139) Portable Media Players (cid:139) GPS Receivers (cid:139) Cellular Phones (cid:139) PDAs and Handheld Computers Typical Application Circuit Vin L1 Vo 22μH LED1 LED2 C2 0.22μF LED3 U2 6 1 W T VIN S OU 5 V SC4509 LED4 EN/SS EN/SS D FB 4 N 3 G 2 R1 C1 1μF March 26, 2007 1 www.semtech.com

SC4509 POWER MANAGEMENT PRELIMINARY Absolute Maximum Rating Exceeding the specifi cations below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specifi ed in the Electrical Characteristics section is not implied. Exposure to Absolute Maximum rated conditions for extended periods of time may affect device reliability. Parameter Symbol Maximum Units Input Supply Voltage V -0.3 to 20 V IN SW Voltage V -0.3 to 30 V SW Maximum Output Voltage V 30 V OUT Feedback Voltage V -0.3 to 20 V FB EN/SS Voltage V -0.3 to V + 0.3 V EN/SS IN Maximum Junction Temperature T 125 °C J Storage Temperature Range T -65 to +150 °C STG MLPD-W8 78 Thermal Impedance θ C/W Junction to Ambient(1) JA SOT23-6 165 Lead Temperature (Soldering), 10s (SOT23-6 package only) T 300 °C LEAD Peak IR Flow Temperature, (10-40sec) T 260 °C PKG ESD Rating (Human Body Model)(2) V 2 kV ESD Note: 1) Calculated from package in still air, mounted to 3”x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards. 2) Tested in accordance to JEDEC standard JESD22-A114B. Electrical Characteristics Unless specifi ed: V = V = 3.6V; C = 1μF; C = 0.22μF; L = 22μH; unless otherwise noted, T = +25°C for Typ, -40ºC to 85°C for Min and Max. IN EN/SS IN OUT A Parameter Symbol Conditions Min Typ Max Units Input Voltage V 2.7 10 V IN Quiescent Current I No switching 2.6 3.3 mA Q Feedback Voltage V 182 199 216 mV FB Feedback Pin Bias Current I 35 100 nA QFB Switching Frequency f T=25 °C 1.0 1.2 1.4 MHz OSC A Maximum Output Voltage V 20 V OUT Switch Saturation Voltage V I = 85mA; T=25 °C 160 300 mV CESAT SW A Maximum Duty Cycle D V = GND 90 % MAX FB Switch Current Limit I I = 0; T=25 °C 300 500 700 mA cl LOAD A Switch Leakage Current I V = 5V; V = Open 0.01 5.0 μA LKG SW OUT Shutdown Current I V = GND; V = 3V; V = Open 3 5 μA SHD EN/SS IN OUT PWM Dimming Frequency(1) f 1 10 kHz DIM EN/SS Threshold Low V 50 mV IL EN/SS Threshold High V 1.8 V IH © 2007 Semtech Corp. 2 www.semtech.com

SC4509 POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specifi ed: V = V = 3.6V; C = 1μF; C = 0.22μF; L = 22μH; unless otherwise noted, T = +25°C for Typ, -40ºC to 85°C for Min and Max. IN EN/SS IN OUT A Parameter Symbol Conditions Min Typ Max Units EN/SS Input Low Current I V = GND 1.0 μA IL EN/SS EN/SS Input High Current I 60 100 μA IH Output Over-Voltage Protection OVP 25 30 V Schottky Forward Drop V I = 150mA 0.7 V f_sch D Schottky Leakage Current I V = 25V; V = GND 1.0 4.0 μA f_sch OUT SW Note: 1. Guaranteed by design. © 2007 Semtech Corp. 3 www.semtech.com

SC4509 POWER MANAGEMENT PRELIMINARY Pin Confi guration Ordering Information Part Numbers Package VOUT 1 6 SW SC4509SKTRT(1)(2) SOT23-6 GND 2 5 VIN SC4509WLTRT(1)(2) MLPD-W8 2mmx2mmx0.75mm FB 3 4 EN/SS SC4509EVB(3) Evaluation Board 6-pin - SOT23 Notes: (1) Only available in tape and reel packaging. A reel contains 3000 devices. (2) Lead-free package. This product is fully WEEE and RoHS compliant. (3) Specify package preference when ordering. FB 1 8 EN/SS TOP VIEW GND 2 7 VIN GND 3 6 SW VOUT 4 5 VOUT T 8-pin - MLPD 2X2 Marking Information TOP MARK BP00 BOTTOM MARK yyww Marking for SOT23, 6 Lead Package: yyww = Datecode (Example: 0652) © 2007 Semtech Corp. 4 www.semtech.com

SC4509 POWER MANAGEMENT Pin Descriptions SOT23 MLPD 2X2 Pin Name Function Cathode side of the Schottky output voltage. Connect a 0.22μF capacitor from this 1 4, 5 VOUT pin to ground. 2 2,3 GND Ground connection Feedback input pin. Connect a resistor from this pin to GND to program the LED 3 1 FB current. Enable pin. When connected to logic high, the converter is enabled. When con- 4 8 EN/SS nected to logic low, the converter is disabled. The LED brightness can be controlled by applying a PWM signal to this pin. 5 7 VIN Input voltage pin. Connect a 1μF capacitor from this pin to GND. 6 6 SW Switching pin - collector of the internal switch. N/A T Exposed pad (bottom); connect to GND directly beneath package. © 2007 Semtech Corp. 5 www.semtech.com

SC4509 POWER MANAGEMENT PRELIMINARY Block Diagram SW Internal Schottky VOUT FB VIN VREF 199mV PWM OVP 1.25V R Q S ∑S GND EN/SS Ramp Generator 1.2MHz Oscillator Theory of Operation The SC4509 is a constant frequency PWM step-up regu- Over-Voltage Protection (OVP) lator IC designed to operate with an input voltage range To prevent the output voltage from exceeding the maxi- from 2.7V to 10V. mum switch voltage rating (30V), an over-voltage protec- tion circuit is integrated. As soon as the output voltage A maximum output voltage of 20V allows for up to fi ve LEDs exceeds the OVP threshold, the converter stops switching to be connected in series, providing even illumination by and the output voltage starts to drop. When the output passing the same output current through each LED. voltage drops back below the OVP threshold, the convert- er resumes operation. This sequence will repeat for as Designed for a low 199mV, the feedback voltage has a long as is necessary. direct effect on the converter effi ciency. Because the volt- age drop across the feedback resistor does not contribute Enable and PWM Dimming to the output power (LED brightness), the lower the feed- The SC4509 provides the EN/SS pin to serve multiple back voltage, the higher the effi ciency. A 1.2MHz oscillator functions. Its main function is as an enable pin (active frequency saves board space by reducing external compo- high). It also can be used to control LED brightness nent sizes, making the SC4509 ideal for battery-operated when a PWM signal (up to 10kHz) of varying duty cycle is products. applied. A third function acts as a soft-start control. Soft start can be implemented by ramping the voltage applied The SC4509 can be confi gured as a voltage regulated to the pin at startup or by slowly increasing the PMW duty boost converter or as a current-regulating boost converter cycle. for driving white LEDs. The device is designed to be stable without additional external components in both cases. © 2007 Semtech Corp. 6 www.semtech.com

SC4509 POWER MANAGEMENT Applications Information Programming the LED Current Please refer to the Typical Application Circuit on page 1. The LED current is programmed by connecting a resistor (R1) between the FB pin and GND. The LED current in mA is given by the following equation: I = 199/R1 LED where R1 value is in Ohms. Setting the Output Voltage The non-inverting input of the internal error amplifi er is tied to a 199mV voltage reference. A simple voltage divider (R1 at the top and R2 at the bottom) sets the converter output voltage. Please refer to the Application Circuit for OLED Panels on the next page. The voltage feedback gain h = 0.199/Vo is related to the divider resistors value as R2 h (cid:32) R1(cid:14)R2 Once either R1 or R2 is chosen, the other can be calcu- lated for the desired output voltage Vo. Since the number of standard resistance values is limited, the calculated resistance may not be available as a standard value resis- tor. As a result, there will be a set error in the converter output voltage. This non-random error is caused by the feedback voltage divider ratio. It cannot be corrected by the feedback loop. © 2007 Semtech Corp. 7 www.semtech.com

SC4509 POWER MANAGEMENT PRELIMINARY Application Circuit for OLED Panels L1 Vo VIN 22μH OLED PANEL U2 6 1 R1 5 VIN SW OUT V SC4509 C2 4 D 3 1μF EN/SS EN/SS N FB G R2 2 C1 1μF © 2007 Semtech Corp. 8 www.semtech.com

SC4509 POWER MANAGEMENT Typical Characteristics Effi ciency vs. LED Current Effi ciency vs. LED Current V = 2.7V, V = 16V, (4 LED) V = 3.3V, V = 16V, (4 LED) IN OUT IN OUT 80% 85% 75% 80% 70% 75% 70% 65% %) %) 65% cy ( 60% cy ( 60% en 55% en ci ci 55% fi fi Ef 50% Ef 50% 45% 45% 40% 40% 35% 35% 30% 30% 0 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 ILED (mA) ILED (mA) Effi ciency vs. LED Current Effi ciency vs. LED Current vs. Input Voltage V = 3.6V, V = 16V, (4 LED) V = 12V, (3 LED) IN OUT OUT 85% 85% 80% 80% 75% 75% 70% 70% VIN = 2.7V 65% 65% VIN = 3.6V %) 60% %) 60% cy ( cy ( n 55% n 55% e e ci ci Effi 50% Effi 50% 45% 45% 40% 40% 35% 35% 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 0 5 10 15 20 25 30 35 ILED (mA) ILED (mA) Feedback Voltage vs. Temperature vs. LED Current, Frequency vs. Temperature vs. Input Voltage, V = 16V V = 16V OUT OUT 203.0 1.20 202.0 VIN = 2.7V 1.15 ILED = 20mA 201.0 mV) 200.0 ILED = 30mA y (MHz) 1.10 VIN = 3.3V BK ( enc VIN = 3.6V F qu 199.0 e Fr 1.05 198.0 197.0 1.00 -40 -20 0 20 40 60 80 100 -40 -20 0 20 40 60 80 Temperature (Deg. C) Temperature (Deg. C) © 2007 Semtech Corp. 9 www.semtech.com

SC4509 POWER MANAGEMENT PRELIMINARY Typical Characteristics (Cont.) EN/SS Input Current vs. EN/SS Voltage vs. Temperature, Output Voltage vs. EN/SS Voltage vs. Temperature, V = 3.6V; V = 16V V = 3.6V; V = 16V IN OUT IN OUT 55.0 16.0 50.0 45.0 14.0 40°C 40.0 25°C 25°C 12.0 35.0 V) I (μA)EN/SS 2350..00 40°C VOUT ( 180..00 85°C 20.0 15.0 6.0 85°C 10.0 4.0 5.0 0.0 2.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 VEN/SS (Volts) VEN/SS (Volts) LED Current vs. PWM Dimming Duty Cycle LED Current vs. PWM Dimming Duty Cycle V = 3.6V; V = 16V; FPWM = 10kHz V = 3.6V; V = 16V; FPWM = 1kHz IN OUT IN OUT 22 22 20 20 18 18 16 16 14 12 mA) 14 mA) (ILED 12 I (LED 180 6 10 4 8 2 6 0 15 25 35 45 55 65 75 85 95 0 10 20 30 40 50 60 70 80 90 100 DTY (%) DTY (%) Switch Current Limit vs. Complementary Switch Current Limit vs. Temperature vs. Duty Cycle (1-D) vs. Temperature Complementary Duty Cycle (1-D) 800 700 -40°C 650 700 10% 20% 600 A) m 600 550 Current Limit ( 450000 0°C ent Limit (mA) 445050000 60% 25°C urr 90% 300 C 350 40% 85°C 300 200 250 100 200 0 10 20 30 40 50 60 70 80 90 100 -40 -20 0 20 40 60 80 100 (1-D) (%) Temperature (Deg. C) © 2007 Semtech Corp. 10 www.semtech.com

SC4509 POWER MANAGEMENT Typical Characteristics (Cont.) Switch Complementary Duty Cycle vs. Startup Current Input Voltage vs. LED Current, V = 16V, (4 LED) V = 3.6V; I = 30mA; V = 16V (4 LEDs) OUT IN LED OUT 35.0% 30.0% 25.0% ILED = 20mA 20.0% ILED = 30mA D) (%) 15.0% 1- ( 10.0% 5.0% 0.0% 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 VIN (V) Switching Waveform V = 3.6V; I = 20mA; V = 16V (4 LEDs) IN LED OUT © 2007 Semtech Corp. 11 www.semtech.com

SC4509 POWER MANAGEMENT PRELIMINARY Layout Example Top Layer Bottom Layer © 2007 Semtech Corp. 12 www.semtech.com

SC4509 POWER MANAGEMENT Outline Drawing - SOT23-6 DIMENSIONS INCHES MILLIMETERS A DIM MINNOM MAXMIN NOMMAX e1 D A .035 - .057 0.90 - 1.45 A1 .000 - .006 0.00 - 0.15 A2 .035 .045 .051 .90 1.15 1.30 N b .010 - .020 0.25 - 0.50 2X E/2 c .003 - .009 0.08 - 0.22 EI E D .110 .114 .122 2.80 2.90 3.10 E1 .060 .063 .069 1.50 1.60 1.75 1 2 E .110 BSC 2.80 BSC ccc C e .037 BSC 0.95 BSC 2X N/2 TIPS e1 .075 BSC 1.90 BSC e L .012 .018 .024 0.30 0.45 0.60 L1 (.024) (0.60) B N 6 6 01 0° - 10° 0° - 10° aaa .004 0.10 bbb .008 0.20 D ccc .008 0.20 aaa C A2 A SEATING PLANE H C A1 bxN GAGE c bbb C A-B D PLANE 0.25 L 01 (L1) DETAIL A SEE DETAILA SIDE VIEW NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS - A - AND - B - TO BE DETERMINED AT DATUM PLANE-H- 3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. Land Pattern - SOT23-6 X DDIIMMEENNSSIIOONNSS DDIIMM IINNCCHHEESS MMIILLLLIIMMEETTEERRSS CC (.098) (2.50) GG .055 1.40 (C) G Z PP .037 0.95 Y XX .024 0.60 YY .043 1.10 ZZ .141 3.60 P NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. © 2007 Semtech Corp. 13 www.semtech.com

SC4509 POWER MANAGEMENT PRELIMINARY Outline Drawing - MLPD-W8 2x2 B A D DIMENSIONS INCHES MILLIMETERS DIM MIN NOMMAX MIN NOMMAX PIN 1 E A .028 .030 .031 0.70 0.75 0.80 INDICATOR A1 .000 .001 .002 0.00 0.02 0.05 (LASER MARK) A2 (.008) (0.20) b .007 .010 .012 0.18 0.25 0.30 D .075 .079 .083 1.90 2.00 2.10 D1 .059 .063 .067 1.50 1.60 1.70 E .075 .079 .083 1.90 2.00 2.10 E1 .031 .035 .039 0.80 0.90 1.00 A e .020 BSC 0.50 BSC SEATING L .008 .012 .016 0.20 0.30 0.40 aaa C PLANE N 8 8 A1 A2 C bababa ..000033 00..0088 D1 1 2 LxN E/2 E1 N bxN e bbb C A B e/2 D/2 NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. Land Pattern - MLPD-W8 2x2 H R DIMENSIONS DIM INCHES MILLIMETERS C (.079) (2.00) G .051 1.30 Z H .063 1.60 (C) K G K .035 0.90 P .020 0.50 R .006 0.15 Y X .012 0.30 Y .028 0.70 Z .106 2.70 X P NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 3. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE. © 2007 Semtech Corp. 14 www.semtech.com

SC4509 POWER MANAGEMENT Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804 www.semtech.com © 2007 Semtech Corp. 15 www.semtech.com