Features Description The FAN5341 is an asynchronous constant-current LED driver capable of efficiently delivering up to 500mW to a string of up to five LEDs in series. Optimized for small formfactor applications, the 1.2MHz fixed sw itching frequency allow s the use of small chip inductors and capacitors. Asynchronous Boost Converter Internal Schottky Diode Up to 500mW Output Pow er Drives 3 to 5 LEDs in Series 2.7V to 5.5V Input Voltage Range Single-Wire Digital Control Interface to Set LED Brightness Levels 32 Linear Steps 1.2MHz Fixed Sw itching Frequency Soft-Start Capability Input Under-Voltage Lockout (UVLO) Output Over-Voltage Protection (OVP) The FAN5341 uses a simple single-w ire digital control interface to program the brightness levels of the LEDs in 32 linear steps by applying digital pulses. For safety, the device features integrated over-voltage, overcurrent, short-circuit detection, and thermal-shutdow n protection. In addition, input under-voltage lockout protection is triggered if the battery voltage is too low . The FAN5341 is available in a very low profile, small formfactor 2mm x 2mm x 0.55mm 6-lead UMLP package that is green and RoHS compliant. Short-Circuit Detection Thermal Shutdow n (TSD) Protection Low Profile 6-lead 2.0 x 2.0 x 0.55mm UMLP Package Applications Cellular Mobile Handsets Mobile Internet Devices Portable Media Players PDA, DSC, MP3 Players Ordering Information Part Number Temperature Range Package Packing FAN5341UMPX -40 to 85C 6-lead, 2.0 x 2.0mm UMLP Tape and Reel (c) 2009 Semiconductor Component Industries, LLC. October-2017, Rev .2 Publication Order Number: FAN5341/D FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface FAN5341 Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface L = 10H L1 VIN 2.7V to 5.5V 5 2 SW CIN = 10F GND EN 6 FAN5341 1 COUT = 1F 4 3 VOUT FB 3 - 5 LEDs RSET = 12.7 @ ILED =20mA RSET = 10.0 @ ILED =25mA Figure 1. Typical Application Block Diagram VIN GATE DRIVE GND SW 1 VOUT 4 FB D1 6 BOOST CONTROL EN 5 2 3 OVP/ SCD Digital I/F Figure 2. Functional Block Diagram www.onsemi.com 2 FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface Typical Application Diagram VOUT 1 VIN 2 EN 3 P1 GND 6 GND 5 SW 4 FB Figure 3. UMLP6 Package, ^Top View Pin Definitions Pin # Name Description 1 VOUT 2 VIN Input Voltage. Connect to pow er source and decouple w ith CIN to GND. 3 EN Enable Brightness Control. Program dimming levels by driving pin w ith digital pulses. 4 FB Voltage Feedback. The boost regulator regulates this pin to 0.253V to control the LED string current. Tie this pin to a current setting resistor (RSET) betw een GND and the cathode of the LED string. 5 SW Sw itching node . Tie inductor L1 from VIN to SW pin. 6 GND Ground. Tie directly to a GND plane. Boost Output Voltage . Output of the boost regulator. Connect the LEDs to this pin. Connect COUT (Output Capacitor) to GND. www.onsemi.com 3 FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface Pin Configuration Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbol Parameter V IN V FB, V EN Min. Max. Units VIN -0.3 6.0 V FB, EN Pins -0.3 V IN + 0.3 V V SW SW Pin -0.3 22.0 V V OUT VOUT Pin -0.3 22.0 V ESD Electrostatic Discharge Protection Human Body Model per JESD22-A114 Level Charged Device Model per JESD22-C101 3.3 kV 2.0 TJ Junction Temperature -40 +150 C TSTG Storage Temperature -65 +150 C +260 C TL Lead Soldering Temperature, 10 Seconds Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. ON Semiconductor does not recommend exceeding them or designing to absolute maximum ratings. Symbol V IN Parameter Comments VIN Supply Voltage ( ) Min. Max. Units 2.7 5.5 V 6.2 17.5 V 5 25 mA V OUT VOUT Voltage 1 IOUT VOUT Load Current TA Ambient Temperature -40 +85 C TJ Junction Temperature -40 +125 C 500mW Maximum Output Pow er Note: 1. Application should guarantee that minimum and maximum duty-cycle should fall betw een 20-85% to meet the specified range Thermal Properties Junction-to-ambient thermal resistance is a function of application and board layout. This data is measured w ith four-layer 2s2p boards in accordance to JEDEC standard JESD51. Special attention must be paid not to exceed junction temperature TJ(max) at a given ambient temperature TA. Symbol Parameter JA Junction-to-Ambient Thermal Resistance, UMLP6 Package www.onsemi.com 4 Typical Units 70 C/W FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface Absolute Maximum Ratings V IN = 2.7V to 5.5V and TA = -40C to +85C unless otherw ise noted. Typical values are at TA = 25C and V IN = 3.6V. Symbol Parameter Conditions Min. Typ. Max. Units 0.30 0.75 A 2.35 2.15 2.60 2.40 V Power Supplies ISD Shutdow n Supply Current EN = GND, V IN = 3.6V V UVLO Under-Voltage Lockout Threshold V IN Rising V IN Falling V UVHYST Under-Voltage Lockout Hysteresis 2.10 1.90 250 mV EN: Enable Pin V IH HIGH-Level Input Voltage 1.2 V V IL LOW-Level Input Voltage REN EN Pull-Dow n Resistance TLO EN Low Time for Dimming V IN = 3.6V; See Figure 14 0.5 THI Time Delay Betw een Steps V IN = 3.6V; See Figure 14 0.5 s TSD EN Low , Shutdow n Pulse Width 1 ms 200 V IN = 3.6V; from Falling Edge of EN 300 0.4 V 400 k 300 s Feedback and Reference V FB Feedback Voltage IFB Feedback Input Current ILED = 20mA from -40C to +85C, 2.7V V IN 5.5V V FB = 253mV 240 253 266 mV 0.1 1.0 A Power Outputs RDS(ON)_Q1 ISW(OFF) ILIM-PK V IN = 3.6V, ISW = 100mA 600 V IN = 2.7V, ISW = 100mA 650 SW Node Leakage 1 EN = 0, V IN = V SW = V OUT = 5.5V, V LED = 0 0.1 Boost Sw itch Peak Current Limit V IN = 3.6V 750 Boost Sw itch On-Resistance ( ) m 2.0 A mA Oscillator f SW Boost Regulator Sw itching Frequency 1.0 1.2 1.4 18.0 18.9 21.0 MHz Output and Protection V OVP Boost Output Over-Voltage Protection OVP Hysteresis V 0.8 V TLSC V OUT Short Circuit Detection Threshold V OUT Falling V IN - 1.4 V V THSC V OUT Short Circuit Detection Threshold V OUT Rising V IN - 1.2 V DMAX Maximum Boost Duty Cycle (2,3) 85 (2,3) DMIN Minimum Boost Duty Cycle TTSD THYS Thermal Shutdow n Thermal Shutdow n Hysteresis 20 150 35 % C C Notes: 1. SW leakage current includes the leakage current of 2 internal sw itches; SW to GND and SW to VOUT. 2. Not tested in production and guaranteed by design. 3. Application should guarantee that minimum and maximum duty cycle should fall betw een 20-85% to meet the specified range. www.onsemi.com 5 FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface Electrical Specifications 5 LEDs L = 10H COUT = 1.0F ILED = 25mA 5 LEDs L = 4.7H COUT = 1.0F ILED = 25mA Figure 4. 5 LEDs: Efficiency vs. LED Current vs. Input Voltage Figure 5. 5 LEDs: Efficiency vs. LED Current vs. Input Voltage Delta Feedback Voltage (mV) 0.8 4 LEDs L = 10H COUT = 1.0F ILED = 25mA 0.6 0.4 0.2 0 -0.2 -40C +25C -0.4 +85C -0.6 2.7 3 3.3 3.6 3.9 4.2 Input Voltage (V) Figure 7. Delta of V FB Over Input Voltage and Tem perature for 4 LEDs w ith L=10H and COUT=1.0F at ILED=25m A Figure 6. 4 LEDs: Efficiency vs. LED Current vs. Input Voltage 3 LEDs L = 10H COUT = 1.0F ILED = 25mA Figure 8. 3 LEDs: Efficiency vs. LED Current vs. Input Voltage 4 LEDs L = 10H C OUT = 1.0F ILED = 25mA Figure 9. Over-Voltage Protection vs. Input Voltage www.onsemi.com 6 FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface Electrical Specifications Figure 10. Line Transient Response for 4 LEDs at V IN=3.6V 0.6V w ith L=10H, COUT=1.0F and ILED=25m A Figure 12. Startup Waveform for Sw itch Voltage, Inductor Current, V FB and EN for 4 LEDs at V IN=3.6V 0.6V w ith L=10H, COUT=1.0F and ILED=25m A Figure 11. FAN5341 Dim m ing Operation at V IN=3.6V for 4 LEDs w ith L=10H, COUT=1.0F and ILED=25m A Figure 13. Steady-State Waveform for V OUT, Sw itch Voltage and Inductor Current for 4 LEDs at V IN=3.6V 0.6V w ith L=10H, COUT=1.0F and ILED=25m A www.onsemi.com 7 FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface Electrical Specifications FAN5341 does not require the system processor to constantly supply a signal to it to drive the LEDs. Overview The FAN5341 is an inductive current-mode boost serial LED driver that achieves LED current regulation by maintaining 0.253V across the RSET resistor. The current through the LED string (ILED) is therefore given by: I LED 0.253 RSET Digital Dimming Control The FAN5341 starts driving the LEDs at the maximum brightness level. After startup, the control logic is ready to accept programming pulses to decrease the brightness level by the number of positive edges applied to the EN pin. Figure 14 show s the digital pulse dimming control. (1) Over-Current and Short-Circuit Detection The voltage V OUT is determined by the sum of the forw ard voltages across each LED, plus the voltage across RSET, w hich is alw ays 253mV. The boost regulator employs a cycle-by-cycle peak inductor current limit of ~750mA. Driving Five LEDs in Series Over-Voltage / Open-Circuit Protection FAN5341 can drive five LEDs in series but, the forw ard voltage (V F) of the LED MUST be less than 3.5V such that it remains under the over-voltage specification of 18.9V. If the LED string is an open circuit, FB remains at 0V and the output voltag continues to increase in the absence of an over-voltage protection (OVP) circuit. The FAN5341's OVP circuit disables the boost regulator w hen V OUT exceeds 18.9V and continues to keep the regulator off until V OUT drops below 18.1V. UVLO and Soft-Start If EN has been low for more than 1ms, the IC may initiate a "cold start" soft-start cycle w hen EN rises, provided V IN is above the UVLO threshold. Thermal Shutdown When the die temperature exceeds 150C, a reset occurs and remains in effect until the die cools to 125C, at w hich time, the circuit is allow ed to begin the soft-start sequence. Digital Interface The FAN5341 implements a single-w ire digital interface to program the LED brightness to one of thirty-tw o (32) levels spaced in linear steps. With this single-w ire solution, the tHI EN 0 1 tSD tLO 3 2 28 4 29 30 31 0 1 Level 32: 100% Level 32: 100% Level 31 Level 31 Level 30 Level 29 Level 28 Level 5 Shutdown Level 4 Shutdown Level 3 Level 2 Level 1 IWLED Figure 14. Digital Pulse-Dim m ing Control Diagram Application Information Inductor & Output Capacitor Selection # of LEDs Inductor (L) Part Num ber Manufacturer www.onsemi.com 8 Min COUT Part Num ber Manufacturer FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface Circuit Description 3, 4, 5 4.7H Murata NLCV32T-100K-PFR TDK VLF3010AT-100MR49-1 TDK LQH43MN4R7K03 Murata NLCV32T-4R7M-PFR TDK LPF2010T-4R7M ABCO 1.00F CV105X5R105K25AT AVX/Kyocera 1.00F CV105X5R105K25AT AVX/Kyocera Table 1. Recom m ended External Com ponents Component Placement and PCB Recomendations Figure 15. Recom m ended Com ponent Placem ent PCB Recommendations Input Capacitance In a typical application, the input and output capacitors should be placed as close to the IC as possible; no additional capacitance is needed to ensure proper functionality. How ever, in a testing environment, w here the FAN5341 is typically pow ered by a pow er supply w ith relatively long cables, an additional input capacitor (10F) may be needed to ensure stable functioning. This capacitor should be placed close to w here the pow er supply cables attach to the FAN5341 evaluation board. The inductor can be connected to VIN w ith vias through another layer if needed. The feedback pin should be connected back to the IC on a sub-layer. www.onsemi.com 9 FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface 10.0H LQH43MN100K03 0.10 C A 2.0 2X B 1.45 2.0 PIN1 IDENT (0.25) 0.10 C 0.80 1.80 2X 6X 0.50 TOP VIEW 0.65 6X 0.35 0.55 MAX A 0.10 C RECOMMENDED LAND PATTERN (0.15) 0.08 C 0.05 0.00 C SEATING PLANE SIDE VIEW NOTES: A. PACKAGE CONFORMS TO JEDEC MO-229 EXCEPT WHERE NOTED. 1.35 1.45 PIN1 IDENT 1 3 B. DIMENSIONS ARE IN MILLIMETERS. 6X 0.35 0.25 0.10 C A B 0.05 C 6 0.35 6X 0.25 C. DIMENSIONS AND TOLERANCES PER ASME Y14.5M, 1994. 0.70 0.80 D. LANDPATTERN RECOMMENDATION IS BASED ON FSC DESIGN ONLY. E. DRAWING FILENAME: MKT-UMLP06Erev2. 4 0.65 BOTTOM VIEW Figure 16. 6-Lead Molded Leadless Package (UMLP) Package drawings are provided as a service to customers considering ON Semiconductor components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact ON Semiconductor representativ e to v erif y or obtain the most recent rev ision. Package specifications do not expand the terms of ON Semiconductor's worldwide terms and conditions, specifically the warranty therein, which cov ers ON Semiconductor products. www.onsemi.com 10 FAN5341 -- Series Boost LED Driver with Integrated Schottky Diode and Single-Wire Digital Interface Physical Dimensions PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor 19521 E. 32nd Pkwy, Aurora, Colorado 80011 USA Phone: 303-675-2175 or 800-344-3860 Toll Free USA/Canada Fax : 303-675-2176 or 800-344-3867 Toll Free USA/Canada Email: orderlit@onsemi.com N. Amer ican Technical Support: 800-282-9855 Toll Free USA/Canada. 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