DEMO MANUAL DC2319A LTC6363 Fully Differential Amplifier Description The LTC®6363 is a low power, low noise differential op amp with rail-to-rail output swing and good DC accuracy. The amplifier may be configured to process a fully differential input signal or to convert a single-ended input signal to a differential output signal. The differential outputs of the DC2319A can be configured with a first order RC network for driving the differential inputs of an ADC. The DC2319A can be DC-coupled or AC-coupled. Onboard jumpers configure the DC2319A for dual or single power supply. In addition, there are multiple optional surface-mount pads that can be used to change the LTC6363 configuration. Design files for this circuit board are available at http://www.linear.com/demo/DC2319A 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. Table 1. LTC6363 Versions PART NUMBER DEMO CIRCUIT NUMBER DESCRIPTION LTC6363 DC2319A-A Gain Set with External Resistors LTC6363-1 DC2319A-B Internal Gain Resistors G = 1 LTC6363-2 DC2319A-C Internal Gain Resistors G = 2 LTC6363-05 DC2319A-D Internal Gain Resistors G = 0.5 Quick Start Procedure Refer to Figure 1a. Check to ensure that both jumpers, JP1 and JP2, are set as shown. (JP1 to PWR_ON and JP2 to SINGLE SUPPLY). Power up the DC2319A from a single power supply, V+ = 5V and GND = 0V. Connect VIN– to ground using E8. Connect an input voltage to VIN+ using E7. The differential output voltage can then be measured on VOUT– and VOUT+ (E9 and E10). The outputs will be level-shifted to be balanced symmetrical around approximately 2.5V. The difference between the outputs will be the gain multiplied by the difference between the inputs. For a similar setup using a split supply, change the setting of JP2 to DUAL SUPPLY, and connect a negative supply to V–. See Figure 1b. dc2319af 1 DEMO MANUAL DC2319A Quick Start Procedure Figure 1a. DC2319A Connection Diagram (Single Supply) Figure 1b. DC2319A Connection Diagram (Dual Supply) dc2319af 2 DEMO MANUAL DC2319A hardware Configuration Internal or External Gain Settings Table 1 summarizes the gain settings for the various versions of DC2319A. The LTC6363 (without suffix) is a non-committed op amp, which requires external feedback resistors to configure the gain. On the DC2319A-A, these resistors (R1, R2, R3, R4) are all set to 1k to configure a gain of G = 1, as shown in Figure 2. To set other gains, simply replace these resistors with other values. The versions of LTC6363 with suffix (LTC6363-1, LTC6363-2, LTC6363-05) include precision gain resistors internal to the IC. The IC already sets its own gain, to G = 1, G = 2 and G = 0.5 respectively, according to the suffix (see Table 1). Therefore, on DC2319A-B, DC2319A-C and DC2319A-D, the onboard feedback resistors (R3, R4) are not populated, and the input resistors (R1, R2) are shorted to 0Ω, resulting in the circuit of Figure 3. VIN+ VIN+ R2, 1k V+ R4, 1k V+ EXT VOCM VIN– R1, 1k + – EXT VOCM VOUT– LTC6363 – + V– R3, 1k VOUT– LTC6363-X – + VOUT+ V– VOUT+ VIN– DC2319A F02 + – DC2319A F03 Figure 3. DC2319A-B/-C/-D with Gain Setting Resistors Internal to the IC (LTC6363-1/-2/-05) Figure 2. DC2319A-A with External Gain Setting Resistors (LTC6363) dc2319af 3 DEMO MANUAL DC2319A hardware Configuration Single-Ended Input to Differential Output Input or Output Filters To configure the DC2319A for single-ended input to differential output, simply connect a DC bias (such as ground) to VIN– and connect the input signal to VIN+. The differential output is measured on VOUT+ and VOUT–. The unused input can also be grounded on the board by populating R13 or R14. There are many 0Ω resistors and non-installed resistors or capacitors on the DC2319A board which can be populated by appropriate R and C values to configure lowpass filters at the inputs or outputs of the amplifier circuit. Differential Input to Differential Output To configure the DC2319A for differential input to differential output, simply connect the differential input signal to VIN+ and VIN– respectively. The differential output is measured on VOUT+ and VOUT–. AC-Coupled Applications In the default configuration, both the inputs and outputs of the DC2319A are DC-coupled. To AC-couple the DC2319A, at either the inputs or outputs or both, simply replace the 0Ω resistors R5/R6/R11/R12 with appropriate value 0603 capacitors. External Output Common Mode Adjust The DC2319A is by default configured to bias the output common mode at the voltage determined by the LTC6363 IC, which is at approximately the mid-point between the amplifier’s V+ and V– pins. (For example, if single supply is used, the output common mode will be at half the V+ voltage). To set a different value for the output common mode voltage, populate resistors R15 and R16. This will form a resistor divider in parallel with the resistor divider internal to the LTC6363 IC. The most accurate way to set the output common mode voltage is by applying the desired DC bias to the EXT VOCM pin at E5. This will overdrive any of the on-chip or onboard resistor dividers. Active Feedback Filters Various optional feedback components (such as R17, R18, C15, C16, C17, C18) can be populated to configure differential active feedback filters. This is most relevant for the DC2319A-A (the version of LTC6363 without internal gain suffix). The other versions (with internal gain resistors) do not provide access to the internal amplifier feedback nodes, so that it is not possible to configure external feedback filters. See Table 1. Layout The DC2319A PCB layout demonstrates the known bestpractices of PCB layout to get the best performance out of the LTC6363. A ground plane is used, and supply bypass capacitors are close to the supply pins. Use a symmetrical layout around the analog inputs and outputs to minimize the effects of parasitic elements. Shield analog input and output traces with ground to minimize coupling from other traces. Feedback traces are as short as possible. Nevertheless, the DC2319A is a general purpose applications board with many placeholders for optional components. After proto-typing a specific design on the DC2319A, a final PCB layout can be further optimized by removing the placeholders for the unused components. In addition, the DC2319A is designed to accommodate both single supply and dual supply circuits. A PCB design for a single supply application would connect the amplifier’s V– pin directly to the copper ground plane and use only one supply bypass capacitor directly between V+ and ground. dc2319af 4 DEMO MANUAL DC2319A Connectors and Jumpers JP1: Jumper toggles the LTC6363 between SHDN and PWR ON. JP2: Jumper toggles the SUPPLY between DUAL and SINGLE power supplies. If set to dual supply, connect a negative supply voltage to V–. V+: Connect to Positive Power Supply. GND: Connect to Ground. Available at multiple turrets on the board, all shorted together internally. Only need to connect one, others can be used as ground point for measurements. V–: Negative Power Supply Voltage. No need to connect if JP2 is set to single supply. EXT SHDN: Externally Drives the SHDN Pin. No need to connect. To turn the amplifier ON and OFF with a logic signal, remove JP1 (or set to the PWR ON position) and then connect an external logic signal here to EXT SHDN. (See LTC6363 data sheet for logic levels) EXT VOCM: Externally Drives the VOCM Pin. The voltage on this pin sets the output common mode voltage level. If left floating (default setting), then an internal resistor divider develops a voltage that is approximately mid-way between the LTC6363 V+ and V– supply rails. VIN+: Connect noninverting input signal to the amplifier circuit. Available as SMA connector J1 and as turret E7. VIN–: Connect inverting input signal to the amplifier circuit. Available as SMA connector J2 and as turret E8. VOUT–: Measure inverting output signal from the amplifier circuit. Available as SMA connector J3 and as turret E9. VOUT+: Measure noninverting output signal from the amplifier circuit. Available as SMA connector J4 and as turret E10. dc2319af 5 DEMO MANUAL DC2319A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 2 C1, C2 CAP, 0.1µF, X7R, 25V, ±10%, 0805 MURATA, GRM21BR71E104KA01L 2 2 C3, C4 CAP, 4.7µF, X5R, 16V, ±20%, 0805 TAIYO YUDEN, EMK212ABJ475MG-T 3 4 C5, C6, C7, C8 CAP, 0.1µF, X7R, 16V, ±10% 0603 AVX, 0603YC104KAT 4 0 C9 TO C18 CAP, 0603 OPT 5 10 E1 TO E10 TP, TURRET, 0.064" MTG HOLE MILL-MAX, 2308-2-00-80-00-00-07-0 6 2 JP1, JP2 HEADER, 3PIN 1 ROW 0.079CC SULLINS, NRPN031PAEN-RC 7 2 JP1, JP2 SHUNT, 0.079" CENTER SAMTEC, 2SN-BK-G 8 4 J1, J2, J3, J4 CONN SMA 50Ω EDGE-LAUNCH E.F. JOHNSON 142-0701-851 9 0 R13, TO, R18 RES, 0603 OPT 10 8 R5 TO R12 RES, 0Ω, 1/10W, 1%, 0603 NIC, NRC06ZOTRF DC2319A-A Required Circuit Components 1 1 DC2319A-1 GENERAL BOM 2 4 R1, R2, R3, R4 RES, 1k, 1/10W 1%, 0603 NIC, NRC06F1001TRF 3 1 U1 I.C., FULLY DIFFERENTIAL AMPLIFIER I.C., LINEAR TECHNOLOGY LTC6363CMS8 #PBF DC2319A-B Required Circuit Components 1 1 DC2319A-1 GENERAL BOM 2 2 R1, R2, RES, 0Ω, 1/10W, 1%, 0603 NIC, NRC06ZOTRF 3 0 R3, R4 RES, 0603 OPT 4 1 U1 I.C., FULLY DIFFERENTIAL AMPLIFIER I.C., LINEAR TECHNOLOGY LTC6363CMS8-1 #PBF DC2319A-C Required Circuit Components 1 1 DC2319A-1 GENERAL BOM 2 2 R1, R2, RES, 0Ω, 1/10W, 1%, 0603 NIC, NRC06ZOTRF 3 0 R3, R4 RES, 0603 OPT 4 1 U1 I.C., FULLY DIFFERENTIAL AMPLIFIER I.C., LINEAR TECHNOLOGY LTC6363CMS8-2 #PBF DC2319A-D Required Circuit Components 1 1 DC2319A-1 GENERAL BOM 2 2 R1, R2, RES, 0Ω, 1/10W, 1%, 0603 NIC, NRC06ZOTRF 3 0 R3, R4 RES, 0603 OPT 4 1 U1 I.C., FULLY DIFFERENTIAL AMPLIFIER I.C., LINEAR TECHNOLOGY LTC6363CMS8-05 #PBF dc2319af 6 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. D C B A V+ E1 E3 1 R6 0 R5 0 R14 OPT R13 OPT C3 4.7uF R8 0 R7 0 V- V- U1 1 2 OPT -D OPT LTC6363CMS8-2 -C 0 Ohms LTC6363CMS8-1 LTC6363CMS8-05 0 Ohms 1K R3, R4 OPT 1K R1, R2 0 Ohms LTC6363CMS8 -B -A ASSY * U1 R17 OPT * 1KR1 OPT C17 1K *R3 OPT C9 OPT C18 * R4 1K CUSTOMER NOTICE OPT C14 LTC6363CMS8 * * 1KR2 OPT R18 C16 OPT C15 OPT 4 C10 OPT 3 4 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 5 SCALE = NONE KL NC JP1 C6 0.1uF SHDN R10 0 0 R9 1 R16 OPT R15 OPT DATE: N/A SIZE 6 9 - 08 - 14 IC NO. E5 C13 OPT SINGLE EXT VOCM JP2 SUPPLY DUAL R12 0 R11 0 KL VOUT- J4 1 VOUT+ E10 J3 1 DATE 9 - 08 - 14 GND E9 E6 APPROVED 8 7 LTC6363CMS8 DEMO CIRCUIT 2319A SHEET FULLY DIFFERENTIAL AMPLIFIER 8 1 OF 1 1 REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only C12 OPT C11 OPT PROTOTYPE DESCRIPTION 7 REVISION HISTORY TECHNOLOGY V- REV V+ PWR_ON - ECO 6 TITLE: SCHEMATIC C7 0.1uF C8 0.1uF C5 0.1uF E4 EXT SHDN APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 1. ALL RESISTORS ARE IN OHMS, 0603 ALL CAPACITORS ARE IN MICROFARADS, 0603 NOTE : UNLESS OTHERWISE SPECIFIED J2 VIN- E8 J1 1 E7 C4 4.7uF GND 0805 C1 0.1uF 0805 E2 0805 C2 0.1uF GND MAX ± 6V 0805 VIN+ V+ 3 GND 2 1 5 4 3 2 5 4 3 2 8 IN+ IN- 7 SHDN VOCM 2 6 VV+ 3 5 OUTOUT+ 4 2 3 4 5 2 3 4 5 1 D C B A DEMO MANUAL DC2319A Schematic Diagram dc2319af 7 DEMO MANUAL DC2319A 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 dc2319af 8 Linear Technology Corporation LT 0915 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2015