LX1995

LX1995 EVALUATION GUIDE MINIATURE LED DRIVER LX1995 EVUALATION KIT INTEGRATED Copyright © 2004 Rev. 1.0, 2004-08-13 PRODUCTS Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX1995 TABLE OF CONTENTS EVALUATION GUIDE LX1995 EVAL Introduction .............................................................................................................................. ..3 Schematic for LX1995 Evaluation Board ............................................................................................................... 4 Hook up.................................................................................................................................................................. 5 Connections ........................................................................................................................................................... 6 Printed Circuit Board .............................................................................................................................................. 7 Bill of Materials....................................................................................................................................................... 8 Copyright © 2004 Rev. 1.0, 2004-08-13 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 LX1995 INTRODUCING TO PRODUCT EVALUATION GUIDE The LX1995 Evaluation Board (EB) is available from Microsemi for evaluating the performance of the LX1995 LED driver integrated circuit. (See picture 1) The EB contains a small amount of support circuitry that enhances performance in different dimming configurations. (See schematic 1.) In a typical application, some of this circuitry would be eliminated. KEY FEATURES OF THE LX1995 • • • • • • • • • < 1µA Shutdown Current > 85% Maximum Efficiency Efficient at Low Current Levels < 70µA Quiescent Supply Current in Operating Mode VIN Range 1.6V to 5.5V Logic Controlled Shutdown Dimming Options: PWM or Varying DC Voltage Tiny 5-Pin TSOT Package Smallest External Components APPLICATIONS • • • • • • Pagers Wireless Phones PDAs LED Driver Digital Camera Displays GPS Receivers PART SPECIFIC INFORMATION Part Number LX1995-1CSG LX1995-1CSE LX1995-2CSG LX1995-2CSE Switch Current 325mA Description High Efficiency LED Driver 500mA Table 1 – Part Information IC LX1995-1CSG LX1995-1CSE LX1995-2CSG LX1995-2CSE EVALUATION BOARDS LX1995-1SG EVAL LX1995-1SE EVAL LX1995-2SG EVAL LX1995-2SE EVAL Table 2 – Evaluation Board Information Copyright © 2004 Rev. 1.0, 2004-08-13 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 LX1995 SCHEMATIC FOR LX1995 EVAL EVALUATION GUIDE JU1 L1 10µH D1 UPS5817 VIN C2 1µF VOUT GND R1 100K C1 10µF U1 LX1995 IN SHDN GND SW GND OPT T-1.75 LED1 OPTIMITE FB OPT T-1.75 LED2 OPTIMITE SHDN OPT T-1.75 LED3 OPTIMITE R8 100K DC_ADJ OPT T-1.75 R5 9.09K R3 90.9K R2 11.3K LED4 OPTIMITE GND PWM_ADJ C3 0.1µF R4 15 GND Figure 1 – Evaluation Board Schematic Copyright © 2004 Rev. 1.0, 2004-08-13 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX1995 EVALUATION GUIDE LX1995 EVALUATION HOOK UP The following is a demonstration scenario that can be used to evaluate the LX1995: Directions for hook up (DC dimming mode): 1. Install jumper JU1. 2. Connect a 3.6V typical 1A power source between VIN and GND terminals. 3. Apply a 1.5V DC signal to the DC_ADJ terminal. Signal GND can be referenced to GND2 for convenience. 4. Vary the DC signal from 0V to 3V and observe the LEDs dimming. (Measure LED current from LED4 cathode to GND2 if desired. I = V / 15. DC DIMMER 0V to 3V ( DIMMING OPTION 1) + - LED4 LED3 VOUT GND3 LED2 DC_ADJ GND2 LED1 /SHDN C2 PWM_ADJ R1 R4 R8 R2 R3 C3 R5 GND4 PWM 5KHz + - LX1995 MINIATURE LED DRIVER EVALUATION BOARD ( DIMMING OPTION 2) Figure 2 – Typical Hook Up for the LX1995 Eval Board Copyright © 2004 Rev. 1.0, 2004-08-13 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 LX1995 EVALUATION GUIDE CONNECTIONS The LX1995 Evaluation Board has 9 test lead attachment point for applying power and dimming inputs or for monitoring voltages. Function Input Power Power Ground Enable DC dimming PWM dimming Output Voltage Signal Ground Board Label VIN GND /SHDN DC_ADJ PWM_ADJ VOUT GND# Connection Power supply (3.55V+/- 1.95V). Common power supply ground. Connect to GND to disable LX1995. A 5KHz 3.3V logic PWM signal. Test point to monitor voltage across all LEDs. Multiple common grounds for probes. etc Table 3 – Connection Points Hints: For best results, use only one of the three possible LED dimming methods at a time. LED current can be monitored by measuring the voltage from LED4 cathode to GND and dividing by 15 (the value of R4). NOTE: Jumper JU1 must be connected for the LX1995 to function. This jumper can be replaced with a wire loop so the inductor current waveform can be observed using a current probe. Copyright © 2004 Rev. 1.0, 2004-08-13 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX1995 PRINTED CIRCUIT BOARD LAYOUT EVALUATION GUIDE LED4 LED3 VOUT GND3 LED2 DC_ADJ GND2 LED1 /SHDN U1 D1 JU1 GND C1 VIN L1 (800) 877-6458 LX1995 MINIATURE LED DRIVER EVALUATION BOARD Figure 3 – LX1995 Evaluation Board Copyright © 2004 Rev. 1.0, 2004-08-13 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 C2 PWM_ADJ R1 R4 R8 R2 R3 C3 R5 GND4 Page 7 LX1995 BILL OF MATERIALS MISCELLANEOUS COMPONENTS EVALUATION GUIDE Line Item Part Description Manufacturer & Part # MICROSEMI MICROSEMI MICROSEMI COILCRAFT LX1995-xCyy UPWLED UPS5817 LPO3310-103MX Case 0603 Powermite Reference Designators U1 LED# D1 L1 Qty 1 4 1 1 1 1 9 1 Miniature LED Driver 2 LED, White 3 Diode, Schottky, 20V, 1A 4 Inductor, 10µH 5 Jumper 6 3-Pin Header, .100 7 Lead Attachment HW x – denotes switch current yy – denotes Package Type CAPACITORS Line Item 1 2 3 Part Description Capacitor, 10µF, 6.3V, X5R Capacitor, 1.0µF, 50V, X7R Capacitor, 0.1µF, 50V, X7R Part Description MURATA MURATA MURATA GRM319R60J106ME01D C3216X7R1H105K GRM21BR71H104KA01L Case 1206 1206 0805 Reference Designators C1 C2 C3 Qty 1 1 1 RESISTORS Line Item 1 2 3 4 5 Part Description Resistor, 100K Resistor, 11.3K Resistor, 90.9K Resistor, 15 Resistor, 9.09K Part Description PANASONIC PANASONIC PANASONIC PANASONIC PANASONIC ERJ-3EKF1003V ERJ-3EKF1132V ERJ-3EKF9092V ERJ-6ENF15R0V ERJ-3EKF9091V Case 0603 0603 0603 0805 0603 Reference Designators R1, R8 R2 R3 R4 R5 Qty 2 1 1 1 1 Copyright © 2004 Rev. 1.0, 2004-08-13 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8