DEMO MANUAL DC1591A LTC6409 High Speed, Low Noise/Distortion Differential ADC Drivers DESCRIPTION Demonstration circuit 1591A features the LTC®6409 differential ADC driver. It incorporates a variety of passive components to support configurations for varied applications. On this board, two amplifier circuits are provided. One is single-ended, the other is a differential input and output. There is also a calibration circuit to de-embed the effects of other circuit components. The LTC6409 is a high-speed differential amplifier with superior distortion and low noise suitable for demanding communications transceivers, cellular base-stations, and other high-speed signal chain applications. These fully- differential amplifiers accept single-ended or differential inputs with almost no difference in distortion performance. Each part has the ability to adjust the output common-mode voltage without any additional components and flexible input common-mode ranges, which enable input signal DC coupling and level-shifting for ADC driving applications. Design files for this circuit board are available at http://www.linear.com/demo/DC1591A 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. QUICK START PROCEDURE Table 1 shows the function of each SMA connector on the board. Refer to Figure 1 for the connection diagram and follow the procedure below: 1.Connect the power supply to V+ and GND as shown in Figure 1. Typical current consumption of each LTC6409 is about 52mA. Jumper JP1 enables or shuts down the single-ended amplifier. 2.The power supply voltage range is shown in Figure 1. Do not exceed the maximum power supply voltage rating for the parts. 3.Apply an input signal to J1. A low distortion, low noise signal source with an external high order filter will yield the best performance. The J1 input is impedance matched to 50Ω. 4.Observe the output via J2. The output is impedance matched to 50Ω, suitable for the input of a network or spectrum analyzer. Table 1: DC1591A Board I/O Descriptions CONNECTOR FUNCTION J1 (IN) Single-ended Input. Impedance matched to 50Ω, drive from a 50Ω network analyzer or signal source. J2 (OUT) Single-ended Output. Impedance matched to 50Ω, can be used to drive a 50Ω network/spectrum analyzer input. J3 (CAL IN) Calibration Input. Impedance matched to 50Ω, pairing with J4 for calibration. J4 (CAL OUT) Calibration Output. Impedance matched to 50Ω, pairing with J3 for calibration to de-embed the effects of other circuit components. J5 (IN+)/ J6 (IN–) Differential Inputs. They are impedance matched to 300Ω differentially. Signal can be driven from preceding receiver signal chain (i.e., Mixer or I/Q Demodulator). J7 (OUT–)/ J8 (OUT+) Differential Outputs. They are impedance matched to 100Ω differentially. JP1 (SHDN1) Shutdown Jumper. The lower (EN) position enables the single-ended amplifier circuit, while the upper (DIS) puts the amplifier into shutdown mode. JP2 (SHDN2) Shutdown Jumper. The lower (EN) position enables the differential amplifier circuit, while the upper (DIS) puts the amplifier into shutdown mode. E4 (VOCM) Output Common Mode Adjust. By default, this pin is self-biasing within U1 and U2. Override this voltage with other DC voltage source as required. dc1591af 1 DEMO MANUAL DC1591A QUICK START PROCEDURE VCC = 2.7V TO 5.2V POWER SUPPLY + – IMPEDANCE MATCHED TO 50Ω IMPEDANCE MATCHED TO 50Ω DC1591A F01 Figure 1. Proper Measurement Equipment Setup 2 dc1591af DEMO MANUAL DC1591A ADDITIONAL INFORMATION The DC1591A demo board is ready for use out of the box. A single-ended and a differential amplifier circuit are provided for ease of use and with minimum modification. DEMO BOARD VERSIONS Single-Ended Input and Output Configuration J1: The single-ended input can be driven from a 50Ω signal source or network analyzer (usually port 1). J2: The single-ended output can be connected to spectrum analyzer or network analyzer (usually port 2). Differential Inputs and Outputs Configuration J5 and J6: Differential inputs. Typically, signal input to these ports are from a receiver signal chain such as a mixer or I/Q demodulator. J7 and J8: Differential outputs. These ports can drive directly into the differential inputs of an ADC. OUTPUT DRIVE Each amplifier circuit on the demo board is designed to have a 50Ω source impedance at its output to facilitate direct connections to 50Ω terminated test instruments. ENABLE (SHUTDOWN) Jumper JP1 and JP2 control the enable function of U1 and U2, respectively, on DC1591A. When set to the EN position, the part will be on and draws normal operating current. In the DIS position, the part will be in shutdown and draws a very small amount of leakage current. GROUND AND VCC CONNECTIONS DC1591A’s GND connector is not only connected to V– of the LTC6409, it also serves as the demo board ground. For best result, a low impedance return path to the power supply from GND is recommended. Short, low impedance wires to the V+ and GND connectors of DC1591A will yield the best performance from the LTC6409. DRIVING THE INPUTS DC-COUPLED It is possible to configure the DC1591A inputs differentially with DC coupling. Transformer T1 should be removed, and C23 and C24 connections should be replaced with 0Ω resistors. The inputs are now DC-coupled and can be driven single-ended or differentially (resistor values may be changed to balance the source impedances, et cetera. See the product data sheet for more information. Note input bias currents will flow through the amplifier’s input resistors if DC1591A is driven DC-coupled. SCHEMATIC NOTES Note that transformer T2 and the series resistors at the amplifier outputs form a 12.6dB attenuation (if the output has a 50Ω load) that will affect the measured gain of the demo board. This is done so that the output of DC1591A can plug directly into a 50Ω network/spectrum analyzer input, while the amplifier sees a higher 400Ω load impedance. CHANGING THE OUTPUT COMMON-MODE VOLTAGE Turret E4 (VOCM) controls the output common mode voltage of U1 and U2. E4 can be used to level-shift the DC output voltage for optimum system performance. If used for this purpose, transformer T2 should be removed, and C18 and C19 connections can be replaced by 0Ω resistors to allow the DC bias to reach the output. By default, the VOCM voltage is self-biased through resistors internal to the IC’s (U1 and U2). dc1591af 3 DEMO MANUAL DC1591A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 1 2 C1, C5 CAP. CHIP, X7R, 100pF, 50V, 10%, 0402 AVX, 04025C101KAT 2 2 C2, C6 CAP. CHIP, X7R, 0.01μF, 16V, 10%, 0402 AVX, 0402YC103KAT 3 19 C3, C7, C11, C14, C15, C16, C18, C19, C20, C21, C23, C24, C25, C26, C28, C29, C30, C31, C32 CAP. CHIP, X7R, 0.1μF, 16V, 10%, 0402 AVX, 0402YC104KAT 4 2 C4, C8 CAP. CHIP, X5R, 0.47µF, 10V, 10%, 0402 MURATA, GRM155R61A474KE15D 5 2 C9, C10 CAP. CHIP, X7R, 1000pF, 25V, 10%, 0402 AVX, 04023C102KAT 6 1 C12 CAP. CHIP, X5R, 10μF, 10V, 10%, 0805 AVX, 0805ZD106KAT 7 4 C13, C17, C22, C27 CAP. CHIP, X7R, 1.3pF, 25V, 10%, 0402 AVX, 04023J1R3ABWTR 8 3 E1, E3, E4 TESTPOINT, TURRET, 0.065" PBF MILL-MAX, 2308-2-00-80-00-00-07-0 9 0 E2 (OPT) TESTPOINT, TURRET, 0.065" PBF MILL-MAX, 2308-2-00-80-00-00-07-0 10 2 JP1, JP2 HEADER, 3 PINS, 2mm SAMTEC, TMM-103-02-L-S 11 2 JP1, JP2 SHUNT, 2mm CENTER SAMTEC, 2SN-BK-G 12 8 J1, J2, J3, J4, J5, J6, J7, J8 CON., SMA 50Ω EDGE-LANCH CONNEX, 132357 / 142-0701-851 13 8 R1, R7, R14, R18, R27, R31, R36, R37 RES., CHIP, 0Ω 1/16W, 1%, 0402 YAGEO, RC0402FR-070RL 14 0 R2, R6, R13, R15, R16, R19, R26, R32, R35, R38 RES., CHIP, 0402 (OPT) 15 2 R3, R4 RES., CHIP, 100Ω 1/16W, 1%, 0402 YAGEO, RC0402FR-07100RL 16 8 R5, R8, R9, R10, R28, R29, R33, R39 RES., CHIP, 150Ω 1/16W, 0.1%, 0402 YAGEO, RT0402BRE07150RL 17 6 R11, R12, R20, R22, R23, R25, RES., CHIP, 300Ω 1/16W, 1%, 0402 YAGEO, RC0402FR-07300RL 18 2 R17, R30 RES., CHIP, 10Ω 1/16W, 1%, 0402 YAGEO, RC0402FR-0710RL 19 2 R21, R24 RES., CHIP, 75Ω 1/16W, 1%, 0402 YAGEO, RC0402FR-0775RL 20 2 R34, R40 RES., CHIP, 49.9Ω, 1/16W, 1% 0402 VISHAY, CRCW040249R9FKED 21 4 T1, T2, T3, T4 TRANS., TCM4-19 SURFACE MOUNT MINI CIRCUITS, TCM4-19 22 2 U1, U2 DIFFERENTIAL AMPLIFIER/ADC DRIVER LINEAR TECH., LTC6409UDB 23 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT # DC1591A 24 2 STENCIL – TOP & BOTTOM DC1591A 4 dc1591af A B C D SMA J1 1 SMA CAL IN J3 5 1 P Pd T1 S CT Sd 1 2 3 SMA IN+ R18 0 Ohm VOCM J5 R19 OPT E4 SMA IN- J6 1 1 P Pd T3 C28 0.1uF VCM S CT 1 2 3 R31 0 Ohm EN DIS R38 OPT R32 OPT JP2 SHDN2 3 2 1 JP1 3 2 1 C30 R30 10 150 0.1% R39 150 0.1% R33 C26 0.1uF 4 C31 -IN Vocm +IN R23 300 R20 300 6 5 2 C16 0.1uF 6 5 2 C27 1.3pF 1.3pF V+ C13 150 0.1% R28 R25 300 R22 300 R24 75 -IN Vocm +IN V+ +OUT -OUT C14 0.1uF C15 0.1uF -OUT R8 150 0.1% R21 75 U2 LTC6409UDB 0.1uF C20 0.1uF VOCM VOCM 150 0.1% R10 R9 150 0.1% R11 300 R17 10 0.1uF C32 0.1uF SHDN1 Sd EN DIS E2 VCM C24 C23 0.1uF 0.1uF R12 300 TCM4-19 1:4 Xfmr by Mini-Circuits 4 6 R15 OPT C25 0.1uF R37 0 Ohm R16 OPT V+ TCM4-19 1:4 Xfmr by Mini-Circuits 4 6 CALIBRATION PATH R13 OPT R14 0 Ohm U1 LTC6409UDB C22 1.3pF +OUT R29 150 0.1% C17 1.3pF SHDN 3 IN 5 4 3 2 R5 150 0.1% SHDN 3 E 5 4 3 2 4 9 V+ V+ VVV8 10 11 4 7 1 7 1 50 R40 50 R34 0.1uF C21 R4 100 R3 100 C18 Sd CT S T4 Pd P 6 4 C29 0.1uF R6 OPT R35 OPT 3 R7 0 Ohm R36 0 Ohm TCM4-19 1:4 Xfmr by Mini-Circuits 3 2 1 0.1uF C19 0.1uF 3 1 Sd CT S 1 T2 P Pd 6 4 J7 J8 SMA OUT+ SMA OUT- R26 OPT R27 0 Ohm TCM4-19 1:4 Xfmr by Mini-Circuits 3 2 1 2 3 4 5 4 9 V+ V+ VVV8 10 11 5 4 3 2 5 4 3 2 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. 2 3 4 5 R1 1 0 Ohm 1 J4 SMA J2 OUT 2 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. CUSTOMER NOTICE SMA CAL OUT 2 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. R2 OPT 2 3 4 5 2 3 4 5 5 SCALE = NONE APP ENG. JOHN C. PCB DES. NC APPROVALS 2 - E3 DATE: N/A SIZE TECHNOLOGY 0.47uF 1 LTC6409UDB DEMO CIRCUIT 1591A Thursday, June 10, 2010 IC NO. DATE 06-02-10 SHEET 1 OF 1 2 REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only C8 0.1uF 0.01uF C7 100pF 0.1uF 0.47uF C4 C6 0.01uF C3 C5 100pF C2 JOHN C. APPROVED C1 PRODUCTION FAB DIFFERENTIAL AMPLIFIER / ADC DRIVER TITLE: SCHEMATIC GND V+ 1 DESCRIPTION REVISION HISTORY C9 C12 C11 C10 10uF 0.1uF 1000pF 1000pF E1 V+ 2.7V - 5.25V REV ECO A B C D E DEMO MANUAL DC1591A SCHEMATIC DIAGRAM dc1591af 5 DEMO MANUAL DC1591A 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 6 dc1591af Linear Technology Corporation LT 1115 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2015