DEMO MANUAL DC1511A LTM8042, LTM8042-1 1A, 350mA Module LED Driver DESCRIPTION Demonstration circuits 1511A-A and 1511A-B feature the LTM(R)8042 and the LTM8042-1, which are respectively complete 1A and 350mA Module LED drivers. The demonstration circuits are assembled as boost topologies, accepting an input voltage from 3V to 30V and supporting an output up to 32V (see Table 1). The default switching frequency is 600kHz for DC1511A-A and 950kHz for DC1511A-B, but can be adjusted by changing the value of RT. P-channel MOSFET that is necessary for PWM dimming. The RADJ pin/terminal voltage controls the output current. Voltage is either applied directly to the terminal or set by a divider that includes resistor RADJ and the LTM8042's internal 2V reference and divider resistor. Open LED overvoltage protection is also included. Consult the LTM8042/ LTM8042-1 datasheet for further information on how to properly use or modify the circuit. DC1511A is easily configured to support other features, including PWM dimming, analog dimming, buck-boost mode and buck mode (step-down). DC1511A includes a Design files for this circuit board are available at http://www.linear.com/demo PERFORMANCE SUMMARY PARAMETER L, LT, LTC, LTM, Module, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25C CONDITIONS/NOTES Input Voltage Range, VIN (BSTIN) VALUE 3V to 30V (See Table 1) ILED DC1511A-A (LTM8042) DC1511A-B (LTM8042-1) Current Derating May Be Necessary Under Certain VIN, VOUT , Frequency and Thermal Conditions 1A 350mA Switching Frequency RT = 30.1k (DC1511A-A) RT = 16.9k (DC1511A-B) 600kHz 950kHz Maximum Output Voltage (Open LED Voltage) Efficiency 36V VIN = 12V, VLED = 16.7V, ILED = 1A VIN = 12V, VLED = 24.8V, ILED = 350mA 91.5% (See Figure 2) 89% (See Figure 3) BOARD PHOTO dc1511af 1 DEMO MANUAL DC1511A QUICK START PROCEDURE Demonstration circuit 1511A is easy to set up to evaluate the performance of the LTM8042EV/LTM8042EV-1. Refer to Figure 1 for the proper measurement equipment setup and follow the procedure below for a boost (step-up) topology. 1. Connect a string of LEDs with forward voltage 32V or less, but greater than the input voltage, to the LED+ (LED anode) and GND (LED cathode) terminals on the PCB, as shown in Figure 1. 2. With the power off, connect the input power supply to the BSTIN/BKLED- and GND terminals within the ranges specified in Table 1. Preset the DC input voltage within the recommended input voltage range for the appropriate forward voltage of the LED string. Table 1. Input Range for Proper Operation (Refer to the LTM8042/LTM8042-1 Datasheet) DC1511A-A LTM8042 DC1511A-B LTM8042-1 INPUT VOLTAGE (BSTIN/BKLED- TO GND) LED STRING VOLTAGE (LED+ TO GND) INPUT VOLTAGE (BSTIN/BKLED- TO GND) LED STRING VOLTAGE (LED+ TO GND) 5V to 5.8V 6V to 9V 3.2V to 7V 8V to 12V 6.4V to 7.7V 8V to 12V 4.1V to 10V 12V to 16V 8.6V to 11.3V 12V to 16V 4.8V to 12.3V 15V to 21V 11.3V to 13.8V 15V to 21V 5.8V to 15V 18V to 24V 13.4V to 16.5V 18V to 24V 8.5V to 20.8V 24V to 32V 20.5V to 22.5V 24V to 32V 3. Connect the PWM terminal. If PWM is not used, connect PWM to a 5V source or to the input voltage. PWM must be pulled high or the LEDs will remain off. To use the DC1511A in a buck-boost mode topology, make the following modifications to the procedure. 1. At step 1, connect the cathode of the LED string to the BSTIN/BKLED- terminal. The LED forward voltage may be greater than the input voltage for buck-boost mode. 2. At step 2, refer to the datasheet buck-boost mode applications information table. Preset the DC input voltage within the recommended input voltage range for the appropriate forward voltage and current of the LED string. To use the DC1511A in a buck mode (step-down) topology, make the following modifications to the procedure. 1. Remove the 0 jumper at location R8 and instead install the jumper at location R4. This shorts the VCC, TGEN and RUN pins/terminals to BSTOUT/BKIN instead of BSTIN/BKLED-. 2. At step 1, connect the cathode of the LED string to the BSTIN/BKLED- terminal. The LED forward voltage must be less than the input voltage for buck mode. 3. At step 2, connect the input power supply to BSTOUT/ BKIN and GND. Refer to the datasheet buck mode applications information table. Preset the DC input voltage within the recommended input voltage range for the appropriate forward voltage and current of the LED string. 4. Turn the input power supply on. 5. Observe the LED string running at the programmed LED current. 6. For PWM dimming, connect a PWM 100Hz or higher frequency signal to the PWM terminal. 7. Observe the reduction of brightness in the LED string by varying the duty cycle of the PWM signal. dc1511af 2 DEMO MANUAL DC1511A QUICK START PROCEDURE - - - + + - + IIN VIN + ILED ** *Refer to Table 1 for Proper Input Range + - VLED **32V Max VLED DC1511A F01 5V or Figure 1. Proper Measurement Equipment Set-Up (Boost Topology) 93 94 91 92 89 90 EFFICIENCY (%) EFFICIENCY (%) * 88 86 84 85 83 81 79 82 80 87 77 8 9 10 11 12 13 VIN (V) 14 15 16 DC1511A F02 Figure 2. DC1511A-A Efficiency vs VIN Boost Operation, 16.7V at 1A LED String 75 6 8 10 12 14 16 VIN (V) 18 20 22 24 DC1511A F03 Figure 3. DC1511A-B Efficiency vs VIN Boost Operation, 24.8V at 350mA LED String dc1511af 3 DEMO MANUAL DC1511A PARTS LIST LTM8042EV ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C1 Cap., X5R, 4.7F, 50V, 20%, 1206 Taiyo Yuden UMK316BJ475ML-T 2 1 C2 Cap., X5R, 10F, 50V, 20%, 1210 Taiyo Yuden UMK325BJ106MM-T 3 1 C4 Cap., X7R, 0.01F, 25V, 10%, 0603 AVX 06033C103KAT2A 4 1 RT Res., Chip, 30.1k, 0.06W, 1%, 0603 NIC NRC06F3012TRF 5 1 U1 I.C., LED Driver, LGA (77),15mm x 9mm x 4.32mm Linear Technology Corporation LTM8042EV TDK C3216X5R1H105M Additional Demo Board Circuit Components 1 1 C3 Cap., X5R, 1F, 50V, 20%, 1206 2 0 C5 (OPT) Cap., 1206 3 0 RADJ, R2, R3, R5, R7 (OPT) Res., 0603 4 1 RSYNC Res., Chip, 100k, 0.06W, 5%, 0603 NIC NRC06J104TRF 5 2 R1, R6 Res./Jumper, Chip, 0, 1/16W, 1A, 0603 Vishay CRCW06030000Z0EA 6 0 R4 (OPT) Res., 1206 7 1 R8 Res./Jumper, Chip, 0, 1/4W, 1A, 1206 Vishay CRCW12060000ZOEA 8 1 M1 P-Channel MOSFET, 40V, SOT-23 Vishay Si2319DS-T1-E3 #PBF Hardware, for Demo Board Only 1 13 E1, E2, E3, E4, E5, E6, E7, E8, Turret, Testpoint 0.094" E9, E10, E11, E12, E13 Mill-Max 2501-2-00-80-00-00-07-0 REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER LTM8042EV-1 ITEM QTY Required Circuit Components 1 1 C1 Cap., X5R, 2.2F, 50V, 20%, 1206 Taiyo Yuden UMK316BJ225MD-T 2 1 C2 Cap., X5R, 10F, 50V, 20%, 1210 Taiyo Yuden UMK325BJ106MM-T 3 1 C4 Cap., X7R, 0.01F, 25V, 10%, 0603 AVX 06033C103KAT2A 4 1 RT Res., Chip, 16.9k, 0.06W, 1%, 0603 Vishay CRCW060316K9FKEA 5 1 U1 I.C., LED Driver, LGA (77),15mm x 9mm x 4.32mm Linear Technology Corporation LTM8042EV-1 TDK C3216X5R1H105M Additional Demo Board Circuit Components 1 1 C3 Cap., X5R, 1F, 50V, 20%, 1206 2 0 C5 (OPT) Cap., 1206 3 0 RADJ, R2, R3, R5, R7 (OPT) Res., 0603 4 1 RSYNC Res., Chip, 100k, 0.06W, 5%, 0603 NIC NRC06J104TRF 5 2 R1, R6 Res./Jumper, Chip, 0, 1/16W, 1A, 0603 Vishay CRCW06030000Z0EA 6 0 R4 (OPT) Res., 1206 7 0 R8 Res./Jumper, Chip, 0, 1/4W, 1A, 1206 Vishay CRCW12060000ZOEA 8 1 M1 P-Channel MOSFET, 40V, SOT-23 Vishay Si2319DS-T1-E3 #PBF Hardware, for Demo Board Only 1 13 E1, E2, E3, E4, E5, E6, E7, E8, Turret, Testpoint, 0.094" E9, E10, E11, E12, E13 Mill-Max 2501-2-00-80-00-00-07-0 dc1511af 4 DEMO MANUAL DC1511A SCHEMATIC DIAGRAM dc1511af Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 5 DEMO MANUAL DC1511A DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. 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For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright (c) 2004, Linear Technology Corporation dc1511af 6 Linear Technology Corporation LT 1010 * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear.com LINEAR TECHNOLOGY CORPORATION 2010