DEMO MANUAL DC2270A LT3095 Dual-Channel Low Noise Bias Generators DESCRIPTION Demonstration circuit 2270A is a dual-channel low noise bias generator featuring LT3095. The LT3095 generates two low noise bias supplies from a common input voltage range from 3V to 20V. Each channel includes a fixed frequency, peak current mode step-up switching regulator and a low noise, single resistor programmable linear regulator. The maximum load current is 50mA for each channel. 2MHz. The SYNC pin on the demo board is grounded by default. To synchronize to an external clock, move JP1 to SYNC and apply the external clock to the SYNC turret. The RT resistor (R2) should be chosen to set the LT3095 internal switching frequency to the SYNC frequency. Each boost regulator adjusts its output voltage to 2V above the corresponding linear regulator’s output voltage, optimizing power dissipation, PSRR and transient response. The integrated boost regulator, frequency compensation and Schottky diodes minimize the external component count and simplify system design. The LT3095 data sheet gives a complete description of the device, operation and application information. The data sheet must be read in conjunction with this quick start guide for demo circuit 2270. The switching frequency can be programmed either via oscillator resistor or an external clock from 450kHz to PERFORMANCE SUMMARY The LT3095 is available in a thermally enhanced 24-Lead 3mm × 5mm QFN package. Design files for this circuit board are available at http://www.linear.com/demo/DC2270A L, LT, LTC, LTM, 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 = 25°C SYMBOL PARAMETER VIN Input Voltage Range CONDITIONS MIN VOUT1 Channel1 Output Voltage 4.9 VOUT2 Channel2 Output Voltage 14.7 IOUT1 Channel1 Max Output Current IOUT2 Channel2 Max Output Current fSW Switching Frequency RT = 100kΩ VOUT,P-P Output Voltage Peak-to-Peak Noise VIN = 5V, VOUT = 15V, IOUT = 50mA, fSW = 1MHz 20MHz BW TYP 3 MAX V 5 5.1 V 15 15.3 50 V mA 50 0.95 UNITS 20 mA 1 65 1.05 MHz µV dc2270afa 1 DEMO MANUAL DC2270A QUICK START PROCEDURE Demonstration circuit 2270 is easy to set up to evaluate the performance of the LT3095. Refer to Figure 2 for proper measurement equipment setup and follow the procedure below: 1. Place JP1 on RT position. 2. With power off, connect the input power supply to VIN and GND. Make sure that the input voltage does not exceed 20V. 3. With power off, connect loads from VOUT1 to GND, and VOUT2 to GND. 6. Once the proper output voltage is established, adjust the load within the operating range and observe the output voltage regulation and other parameters. 7. An external clock can be added to the SYNC terminal when SYNC function is used (JP1 on the SYNC position). The set switching frequency should be programmed to the SYNC frequency. See the data sheet section Programming the Switching Frequency for details. 8. The output noise can be measured by J1 and J2. Please refer to Application Notes 70 for details. 4. Turn on the power at the input. 5. Check for the proper output voltages (5V and 15V). NOTE: If there is no output, temporarily disconnect the load to make sure that the load is not set too high or is shorted. VBSTOUT 20mV/DIV VOUT 50µV/DIV VIN = 5V VOUT = 15V ILOAD = 50mA fOSC = 1MHz 20MHz BW 1µs/DIV dc2270a F01 Figure 1. Transient Output Ripple dc2270afa 2 DEMO MANUAL DC2270A QUICK START PROCEDURE *J1 AND J2 ARE THE BNC CONNECTORS TO COAXIAL CABLE FOR NOISE MEASUREMENT. PLEASE REFER TO AN70 APPENDIX B FOR DETIALS Figure 2. Proper Measurement Equipment Setup dc2270afa 3 DEMO MANUAL DC2270A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER CAP., 2.2µF, X7R, 25V, 10%, 0805 MURATA, GRM21BR71E225KA73L Required Circuit Components 1 2 C1, C2 2 2 C3, C4 CAP., 10µF, X7R, 25V, 10%, 1210 MURATA, GRM32DR71E106KA12L 3 2 C5, C6 CAP., 2.2µF, X7R, 25V, 10%, 1210 AVX, 12103C225KAT2A 4 2 C7, C8 CAP., 1µF, X7R, 25V, 10%, 0603 MURATA, GRM188R71E105KA12D 5 1 C9 CAP., 0.1µF, X7R, 6.3V, 10%, 0603 AVX, 06036D104KAT2A 6 1 L1 INDUCTOR, 6.8µH COILCRAFT LPS4012-682MR 7 1 L2 INDUCTOR, 10µH COILCRAFT LPS4012-103MR 8 4 R1, R2, R4, R5 RES., CHIP, 100k, 1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA 9 1 R3 RES., CHIP, 300k, 1/10W, 1%, 0603 VISHAY, CRCW0603300KFKEA 10 1 U1 I.C., REGULATOR, QFN24-3X5-UDD LINEAR TECH., LT3095EUDD#PBF Additional Demo Board Circuit Components 1 0 C10, C11 (OPT) CAP., 0805 2 0 C12, C13 (OPT) CAP., 0603 3 0 R6, R7 (OPT) RES., 0603 4 0 C14 (OPT) CAP, TANT., 10µF, 25V, 20%, 2312 AVX, TAJW106M025RNJ TESTPOINT, TURRET, 0.094" pbf MILL-MAX, 2501-2-00-80-00-00-07-0 Hardware: For Demo Board Only 1 10 E1-E10 2 1 JP1 HEADER 3 PIN 0.079 SINGLE ROW WURTH, 620 003 111 21 3 1 XJP1 SHUNT, 0.079" CENTER WURTH, 608 002 134 21 4 2 J1-J2 CONN, BNC, 5 PINS CONNEX, 112404 dc2270afa 4 DEMO MANUAL DC2270A SCHEMATIC DIAGRAM dc2270afa 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 DC2270A 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. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and observe good laboratory practice standards. Common sense is encouraged. This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation dc2270afa 6 Linear Technology Corporation LT 1015 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2015