LX1993CDU

LX1993 INTEGRATED PRODUCTS High Efficiency LED Driver P RODUCTION DESCRIPTION KEY FEATURES W WW . Microsemi . C OM The LX1993 is a high efficiency step-up boost converter that features a psuedo-hysteretic pulse frequency modulation topology for driving white or color LEDs in backlight or frontlight systems. Designed for maximum efficiency, reduced board size, and minimal cost, the LX1993 is ideal for PDA and digital camera applications. The LX1993 features an internal N-Channel MOSFET and control circuitry that is optimized for portable system design applications. The LX1993 promotes improved performance in battery-operated systems by operating with a quiescent supply current 70µA (typical) and a shutdown current of less than 1µA. The input voltage range is from 1.6V to 6.0V thus allowing for a broad selection of battery voltage applications and start-up is guaranteed at 1.6V input. The LX1993 is capable of switching currents in excess of 300mA and the output current is readily programmed using one external current sense resistor in series with the LEDs. This configuration provides a feedback signal to the FB pin thus maintaining constant output current regardless of varying LED forward voltage (VF). The LX1993 provides an additional feature for simple dynamic adjustment of the output current (i.e., up to 100% of the maximum programmed current). Designers can make this adjustment by generating an analog reference signal or a PWM signal applied directly to the ADJ pin and any PWM amplitude is readily accommodated via a single external resistor. The LX1993 is available in the 8-Pin MSOP and thus requires a very small PCB area. > 80% Maximum Efficiency 70µA Typical Quiescent Supply Current Externally Programmable Peak Inductor Current Limit For Maximum Efficiency Logic Controlled Shutdown < 1µA Shutdown Current Dynamic Output Current Adjustment Via Analog Reference Or Direct PWM Input 8-Pin MSOP Package APPLICATIONS Pagers Wireless Phones PDAs Handheld Computers LED Driver Digital Camera Displays IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com PRODUCT HIGHLIGHT SW IN OUT SHDN Li-Ion ON OFF LX1993 FB ADJ GND CS LX1993 LX1993 PACKAGE ORDER INFO Plastic MSOP DU 8-Pin TA (°C) 0 to 70 LX1993CDU RoHS Compliant / Pb-free Transition DC: 0432 Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1993CDU-TR) Copyright © 2000 Rev. 1.0b, 2005-03-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX1993 INTEGRATED PRODUCTS High Efficiency LED Driver P RODUCTION ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT SW IN FB SHDN 1 2 3 4 8 7 6 5 OUT GND CS ADJ W WW . Microsemi . C OM Supply Voltage (VIN) ........................................................................-0.3V to 7.0V Feedback Input Voltage (VFB) ................................................-0.3V to VIN + 0.3V Shutdown Input Voltage (V SHDN ) ...........................................-0.3V to VIN + 0.3V Adjust Input Voltage (VADJ) ....................................................-0.3V to VIN +0.3V Output Voltage (VOUT).......................................................................-0.3V to 25V Switch Voltage (VSW) ........................................................-0.3V to (VOUT + 1.0V) Switch Current (ISW) .............................................................................500mArms Operating Junction Temperature.................................................................. 150°C Storage Temperature Range...........................................................-65°C to 150°C Peak Package Solder Reflow Temp. (40 second max. exposure) ... 260°C (+0, -5) Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of specified terminal. DU P ACKAGE (Top View) RoHS / Pb-free 100% Matte Tin Lead Finish FRONT MARKING THERMAL DATA • 206°C/W 39°C/W • 1993 C MSC pin 1 indicator DU Plastic MSOP 8-Pin THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA THERMAL RESISTANCE-JUNCTION TO CASE, θJC Junction Temperature Calculation: TJ = TA + (PD x θJC). The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. FUNCTIONAL PIN DESCRIPTION NAME IN FB DESCRIPTION Unregulated IC Supply Voltage Input – Input range from +1.6V to +6.0V. Bypass with a 1µF or greater capacitor for low voltage operation. Feedback Input – Connect to a current sense resistor between the load and GND to set the maximum output current. Active-Low Shutdown Input – A logic low shuts down the device and reduces the supply current to 120Hz. Or when using a DC adjustment voltage. Use this position to short out LED # 3 and / or LED # 4. APPLICATIONS APPLICATIONS Note: Always put jumpers in one of the two possible positions Copyright © 2000 Rev. 1.0b, 2005-03-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 LX1993 INTEGRATED PRODUCTS High Efficiency LED Driver P RODUCTION APPLICATION INFORMATION (CONTINUED) W WW . Microsemi . C OM Table 3: Factory Installed Component List for the LX1993 Evaluation Board Quantity 1 1 2 2 1 1 1 2 1 1 1 1 4 5 Part Reference CR1 L1 C1, C2 C3, C4 R4 R3 R2 R6, R8 R1, R5 R7 VR1 VR2 LED1 - 4 JB1 - JB3 Description Rectifier, Schottky, 1A, 20V, Powermite Type SMT Inductor, 47uH, 540mA, SMT Capacitor, Ceramic X5R, 4.7uF, 25V, 1210 Type SMT Capacitor, Ceramic X7R, 0.1uF, 50V, 0805 Type SMT Resistor, 15 Ohm, 1/10W, 0805 Type SMT Resistor, 590K, 1/16W, 0603 Type SMT Resistor, 100, 1/16W, 0603 Type SMT Resistor, 100K, 1/16W, 0603 Type SMT Resistor, 10K, 1/16W, 0603 Type SMT Trimpot, 50K, 1/2W, Through Hole Type IC, Voltage Reference, 1.25 Volts, SOT23 Type SMT Diode, Zener, 20V, 1W Powermite Type SMT White LED Header, 3 Pos Vertical Type Manufacturer Microsemi Toko Taiyo Yuden Murata Panasonic Panasonic Panasonic Panasonic Panasonic Bourns Microsemi Microsemi Chicago Miniature 3M Part Number UPS5817 A920CY-470 CETMK325BJ475MN GRM40X7R104M050 ERJ6ENF15R0 ERJ3EKF5903 ERJ3EKF1000 ERJ3EKF1003 ERJ3EKF1002 3352E-1-503 LX432CSC 1PMT4114 CMD333UWC 929647-09-36 5 Jumper 3M 929955-06 Note: The minimum set of parts needed to build a working power supply are: CR1, L1, C1, C2, R2, R4, U1. Evaluation board P/L subject to change without notice. L1 47µH CR1 UPS5817 VBAT VPOT VCC C1 4.7µF 25V C2 4.7µF 25V GND VOUT VCC R1 10k C3 0.1µF 50V CMD333UWC IN SHDN ADJ GND SW OUT CMD333UWC FB CS R2 100Ω CMD333UWC VR2 20V 1W 1PMT4114 LED4 LED3 ON OFF SHDN CMD333UWC R3 590K R4 15Ω R8 100K VADJ VADJ R5 10k VFDBK APPLICATIONS APPLICATIONS VPOT R6 100k C4 4.7µF 25V VR1 LX432 R7 50k Figure 4 – LXE1993 Boost Evaluation Board Schematic Copyright © 2000 Rev. 1.0b, 2005-03-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8 LX1993 INTEGRATED PRODUCTS High Efficiency LED Driver P RODUCTION CHARACTERISTIC CURVES W WW . Microsemi . C OM 365 340 IPEAK (mA) 315 290 265 240 215 190 0 1000 2000 3000 4000 RCS (Ohms) Figure 5: Example of Peak Current versus RCS value Conditions: VIN = 2.5V (bottom), 3.3V (middle) & 4.5V (top) @ TA = 25oC Figure 6: VOUT and Inductor Current Waveforms. Channel 1: VOUT (AC coupled; 100mV/div) Channel 2: Inductor Current (100mA/div.) 4 LED Configuration: VIN = 3.0V 85% 80% 90% 85% 80% Efficiency Efficiency 75% 70% 65% 60% 55% 50% 1 6 11 LED C ur r ent ( mA ) 16 75% 70% 65% 60% 55% 50% 1 6 11 LED C ur r ent ( mA ) 16 21 Figure 7: Efficiency vs. LED Output Current. 2 LED Configuration: VIN = 3.5V, L = 47µH, RCS = 100Ω Note: Data taken from LXE1993 Evaluation Board 100% 90% Figure 8: Efficiency vs. LED Output Current. 2 LED Configuration: VIN = 5.0V, L = 47µH, RCS = 100Ω Note: Data taken from LXE1993 Evaluation Board 100% 90% Efficiency 80% 70% 60% 50% 0 5 10 15 LED C ur r ent ( mA ) 20 Efficiency 80% 70% 60% 50% 0 5 10 15 LED C ur r ent ( mA ) 20 CHARTS CHARTS Figure 9: Efficiency vs. LED Output Current. 4 LED Configuration: VIN = 3.5V, L = 47µH, RCS = 100Ω Note: Data taken from LXE1993 Evaluation Board Figure 10: Efficiency vs. LED Output Current. 4 LED Configuration: VIN = 5.0V, L = 47µH, RCS = 100Ω Note: Data taken from LXE1993 Evaluation Board Copyright © 2000 Rev. 1.0b, 2005-03-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 9 LX1993 INTEGRATED PRODUCTS High Efficiency LED Driver P RODUCTION CHARACTERISTIC CURVES W WW . Microsemi . C OM 1.40 RDS_on (Ohms) 1.30 1.20 1.10 1.00 0 25 50 o RDS_on (Ohms) 75 1.10 1.00 0.90 0 .80 0 25 50 o 75 Temperature C Temperature C Figure 11: RDS(on) vs. Temperature Condition: VIN = 3.0V; ISW = 10mA Figure 12: RDS(on) vs. Temperature Condition: VIN = 5.0V; ISW = 10mA 145.00 140.00 7.00 6.00 IMIN (mA) 135.00 130.00 125.00 0 25 50 o ICS (µ A) 75 5.00 4.00 3 .00 0 25 50 o 75 Temperature C Temperature C Figure 13: IMIN versus Temperature. Condition: VIN = 3.0V Figure 14: ICS versus Temperature. Condition: VIN = 3.0V CHARTS CHARTS Figure 15: Start-Up Waveforms. Condition: VIN = 3.6V, CH1 = VOUT, CH2 = VSW, CH4 = IL Copyright © 2000 Rev. 1.0b, 2005-03-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 10 LX1993 INTEGRATED PRODUCTS High Efficiency LED Driver P RODUCTION PACKAGE DIMENSIONS W WW . Microsemi . C OM DU 8-Pin Miniature Shrink Outline Package (MSOP) A Dim A B C D G H J K L M N P B H G P C N L K M D MILLIMETERS MIN MAX 2.85 3.05 2.90 3.10 – 1.10 0.25 0.40 0.65 BSC 0.38 0.64 0.13 0.18 0.95 BSC 0.40 0.70 3° 0.05 0.15 4.75 5.05 INCHES MIN MAX .112 .120 .114 .122 – 0.043 0.009 0.160 0.025 BSC 0.015 0.025 0.005 0.007 0.037 BSC 0.016 0.027 3° 0.002 0.006 0.187 0.198 Note: Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(0.006”) on any side. Lead dimension shall not include solder coverage. MECHANICALS MECHANICALS Copyright © 2000 Rev. 1.0b, 2005-03-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 11 LX1993 INTEGRATED PRODUCTS High Efficiency LED Driver P RODUCTION NOTES W WW . Microsemi . C OM NOTES NOTES PRODUCTION DATA – Information contained in this document is proprietary to Microsemi and is current as of publication date. This document may not be modified in any way without the express written consent of Microsemi. Product processing does not necessarily include testing of all parameters. Microsemi reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright © 2000 Rev. 1.0b, 2005-03-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 12