DEMO MANUAL DC1684A-A /DC1684A-B LTC2758/LTC2752 Dual SPI IOUT 18-Bit/16-Bit DACs Description Demonstration circuit 1684A-A features the LTC®2758A 18-bit SoftSpan™ IOUT DAC. DC1684A-B features the pin-compatible 16-bit LTC2752A. The digital interface is a simple, 4-wire Serial Peripheral Interface (SPI), augmented with separate CLEAR and LDAC pins that reset the output to zero and load the DAC code, respectively. These devices feature six output ranges: 0V to 5V, 0V to 10V, ±5V, ±10V, ±2.5V, and –2.5V to 7.5V. These ranges are programmable through the SPI interface or through separate span control pins if SoftSpan operation is not needed. Voltage input offset and gain adjustment pins facilitate trimming of residual DC errors without impacting the excellent temperature stability of this device. The DC1684A-B uses LT®1468 amplifiers recommended for 16-bit applications. The DC1684A-A uses low noise, low offset LT1012A amplifiers for reference inversion, and a composite amplifier for I-V conversion that provides 18-bit accuracy and fast settling. Amplifier selection is detailed in the LTC2758 and LTC2752 data sheets. Design files for this circuit board are available at http://www.linear.com/demo/DC1684A L, LT, LTC, LTM, µModule, Linear Technology and the Linear logo are registered trademarks and SoftSpan and QuikEval are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Board Photo RIBBON CABLE TO DC590 CONTROLLER DAC CONNECTIONS ANALOG POWER SUPPLY (NORMALLY ±15V) dc1684aa/ab F01 Figure 1. Connection Diagram dc1684aabfb 1 DEMO MANUAL DC1684A-A /DC1684A-B Quick Start Procedure Connect a low noise ±15V power supply to the AMPV+, GND, and AMPV– turret posts on the DC1684A board. Connect J1 to a DC590 USB serial controller using the supplied 14-conductor ribbon cable. Connect DC590 to a host PC with a standard USB A/B cable. Run the evaluation software supplied with the DC590, or download it from www.linear.com/software. The correct control panel will be loaded automatically (shown in Figure 2). The software automatically sets the LTC2758A / LTC2752A outputs ac- cording to the entries in the control panel. A square wave option is available to test the settling time. The MSPAN jumper should be set to 0 if software span control is desired. Setting MSPAN high (1) causes the S2, S1 and S0 pins to set the span according to the table printed on the board. The corresponding span should be selected in the software to ensure that the calculated DAC code is correct. Additional software documentation may be available from the Help menu item, as features may be added periodically. Figure 2. Software Screenshot dc1684aabfb 2 DEMO MANUAL DC1684A-A /DC1684A-B Hardware Setup JUMPERS ANALOG CONNECTIONS (TURRET POSTS) MSPAN: Manual Span Control Pin. MSPAN is used to configure the LTC2758/LTC2752 for operation in a single, fixed output range. If MSPAN is 1, it will be configured for single span use. If MSPAN is 0, it will be set through the QuikEval™ software. Default position is 0 (low). OUTA/B: DAC Voltage Outputs. S0, S1, S2: Used to set the fixed output range if MSPAN is 1. Table 1. MSPAN Configuration S2 S1 S0 SPAN 0 0 0 0V to 5V 0 0 1 0V to 10V 0 1 0 ±5V 0 1 1 ±10V 1 0 0 ±2.5V 1 0 1 –2.5V to 7.5V GEADJA, GEADJB: Gain Adjust Pins. If no adjustments are required, select GND. Selecting EXT connects the pin to the turret, allowing external adjustment to null gain error or compensate for reference errors. VOSADJA,VOSADJB: Offset Adjustment Selection for DACA or DACB. If no offset adjustment is required, select GND. Selecting EXT connects the offset pin to the turret, allowing external adjustment of offset. VREFA,VREFB: Select Source for VREF on Either DACA or DACB. 5V connects to onboard LTC6655 5V reference; EXT connects to the turret, allowing an external reference to be used. VREFA/B: DAC Reference Voltages. If the on-board LTC6655 references are selected, the voltage may be measured at these points. If a remote reference is selected, then an external reference must be applied to these points. VOSADJA/B: DAC Offset Adjust Inputs. Use only if the VOSA jumper is set to EXT. The nominal range of these pins is ±5V, which will provide ±2048LSB of offset adjustment. GEADJA/B: Gain Adjust Pins. These voltage-control pins can be used to null gain error or to compensate for reference errors. The nominal range of these pins is ±5V, which will provide ±2048LSB of gain adjustment. POWER AND GROUND CONNECTIONS Analog Power: The AMPV+, AMPV –, and GND turret posts are the analog supplies for the on-board DAC amplifiers. These should be connected to a well regulated, low noise ±15V power supply. VCC: Connection to VCC. See the Schematic Diagrams and the description for the VCC jumper. Grounding: Separate power and signal grounds are provided. Signal grounds are the turrets closest to OUTA and OUTB. Use these for measurement ground and output return. Power GND is between the AMPV+ and AMPV – turrets. VCC: Select Source for 5V VCC Supply. Set to 5V for supply by on-board LTC6655 reference (recommended). Set to REG to be supplied by regulated supply from DC590 controller and remove the jumper to supply externally. CLR: Asynchronous Clear Input. Tie to 0 to set all DAC outputs to 0V. LDAC: Asynchronous DAC Load Input. Tie to 0 to update all DACs if CS is high. RFLAG: Reset Flag Output. Remove jumper and probe middle pin for RFLAG status. dc1684aabfb 3 DEMO MANUAL DC1684A-A /DC1684A-B Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 15 C1, C2, C3, C5, C6, C11-C20 CAP., X5R, 10µF, 10V, 20%, 1206 TDK, C3216X5R1A106M 2 8 C4, C7, C36, C37, C38, C39, C40, C41 CAP., X7R, 0.1µF, 10V, 10%, 0603 AVX, 0603ZC104KAT2A 3 2 C10, C21 CAP., X7R, 0.01µF, 10V, 10%, 0603 AVX, 0603ZC103KAT2A CAP., COG, 100pF, 50V, 10%, 0603 AVX, 06035A101KAT2A 4 2 C22, C31 5 0 C23, C29 (OPT.) 6 0 C27, C34 (OPT.) CAP., 0603 7 3 D1, D2, D3 DIODE, BAT54C, SOT23 DIODE, ZETEX, BAT54C-7-F 8 1 J1 CONNECTOR, HD2X7-079 MOLEX, 87831-1420 9 14 JP1-JP14 3-PIN, 0.079", SINGLE ROW HEADER SAMTEC, TMM103-02-L-S 10 14 XJP1-XJP14 SHUNT, 0.079", CENTER SAMTEC, 2SN-BK-G 11 2 JP15, JP16 0.01" JUMPER, SHUNT, SOLDER DOWN SAMTEC, JL-100-25-T 12 1 R1 RES., CHIP, 88.7k, 1/16W, 1%, 0603 VISHAY, CRCW060388K7FKEA 13 5 R2, R31-R34 RES., CHIP, 10k, 1/16W, 1%, 0603 NIC, NRC06F1002TRF 14 3 R3, R4, R5 RES., CHIP, 4.99k, 1/16W, 1%, 0603 NIC, NRC06F4991TRF 15 7 R11-R17 RES., CHIP, 10k, 1/16W, 5%, 0603 NIC, NRC06J103TRF 16 16 TP1-TP16 TURRET, TEST POINT MILL-MAX, 2308-2-00-80-00-00-07-0 LINEAR TECHNOLOGY, LTC6655CHMS8-5#TRPBF 17 1 U2 I.C., LTC6655CHMS8-5, MSOP-8 18 0 U3 (OPT.) I.C., LT1236ACS8-5, SO-8 19 1 U4 I.C., 24LC025, TSSOP-8 MICROCHIP, 24LC025 I /ST 20 1 U5 I.C., LT1761ES5-5, SOT23-5 LINEAR TECHNOLOGY, LT1761ES5-5#TR 21 1 U6 I.C., LT1964ES5-5, SOT23-5 LINEAR TECHNOLOGY, LT1964ES5-5#TRPBF 22 1 U10 I.C., LT1761ES5-BYP, SOT23-5 LINEAR TECHNOLOGY, LT1761ES5-BYP#TRPBF dc1684aabfb 4 DEMO MANUAL DC1684A-A /DC1684A-B Parts List—1684A-A ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 1684A GENERAL BOM 2 2 C24, C30 CAP., COG, 100pF, 50V, 5%, 1206 AVX, 12065A101JAT2A 3 4 C25, C26, C32, C33 CAP., X7R, 1µF, 16V, 10%, 1206 AVX, 1206YC105KAT2A 4 0 C28, C35 (OPT.) CAP., 1206 5 6 R6, R9, R21, R22, R25, R30 RES., CHIP, 1k, 1/16W, 5%, 0603 VISHAY, CRCW06031K00JNEA 6 4 R7, R8, R23, R24 RES., CHIP, 10k, 1/16W, 5%, 0603 NIC, NRC06J103TRF 7 0 R10, R20, R26, R29 (OPT.) RES., CHIP, 0603 8 2 R18, R27 RES., CHIP, 4.02k, 1/16W, 1%, 0603 YAGEO, RC0603FR-074K02L 9 2 R19, R28 RES., CHIP, 10, 1/16W, 5%, 0603 NIC, NRC06J100TRF 10 1 U1 I.C., LTC2758ACLX, 48-LX LINEAR TECHNOLOGY, LTC2758ACLX#TRPBF 11 2 U7, U14 I.C., LT1012ACS8, SO-8 LINEAR TECHNOLOGY, LT1012ACS8#TRPBF 12 2 U8, U12 I.C., LT1360CS8, SO-8 LINEAR TECHNOLOGY, LT1360CS8#TRPBF 13 2 U9, U13 I.C., LTC2054HVCS5, TSOT23-5 LINEAR TECHNOLOGY, LTC2054HVCS5#TRPBF 14 1 U11 I.C., LTC6244HVCDD, 8-PIN-3×3, DD LINEAR TECHNOLOGY, LTC6244HVCDD#TRPBF Parts List—1684A-B ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 1684A GENERAL BOM 2 0 C24, C25, C26, C30, C32, C33 (OPT.) CAP., 1206 3 2 C28, C35 CAP., COG, 33pF, 50V, 5%, 1206 4 0 R6-R9, R18, R19, R21-R25, R27, R28 RES., 0603 5 0 R30 (OPT.) 6 4 R10, R20, R26, R29 RES., CHIP, 0, 1/16W, 0603 AVX, 12065A330JAT2A VISHAY, CRCW06030000Z0EA 7 1 U1 I.C., LTC2752ACLX, 48-LX LINEAR TECHNOLOGY, LTC2752ACLX#TRPBF 8 4 U7, U8, U12, U14 I.C., LT1468CS8, SO-8 LINEAR TECHNOLOGY, LT1468CS8#TRPBF 9 0 U9, U13 (OPT.) I.C., TSOT23-5 10 0 U11 (OPT.) I.C., 8-PIN-3×3,DD dc1684aabfb 5 A B C 1 1 1 1 1 S0 S1 S2 MSPAN 1 1 RFLAG# LDAC# CLR# 1 0 C37 0.1uF 1K OPT C24 100pF OPT ASSY -A -B -B -A 16 R6 18 -B ASSY -BIT -A C41 0.1uF C40 0.1uF 2 U1 OPT 1uF C26 5 2. INSTALL SHUNTS AS SHOWN. 1. ALL RESISTORS ARE 0603. ALL CAPACITORS ARE 0603. DNC S0 S1 S2 M-SPAN CLR LDAC RFLAG CS/LD SCK SDI SRO 2 TP8 EXT LT1468CS8 OPT OPT C30 100pF C28 33pF 4 VREFB U1 * VREFA 2 3 - + 8 2 3 OPT 1uF C32 OPT 4 OPT 1uF C33 OPT 10 R19 33pF OPT C35 0 OPT R20 * VV- 4 9 -5V U11 U14 6 1K OPT OPT 10K R23 OPT 10K 3 1K OPT R25 * R22 VOSADJA OPT R26 0 R27 * OPT 10 R28 1206 C33 * R24 * 0 OPT R29 4 3 4 3 - + - + V- V+ -5V OPT 1K R30 * * 1 1 U13 1206 +5V * C32 -5V V- V+ U9 1206 +5V * C25 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. CUSTOMER NOTICE OPT 4.02K * * 1206 C26 R8 C23 + - R28 + - * * 3 2 C30 OPT. C29 R19 * 5 6 2 SCALE = NONE MARK T. JW 1206 1206 * U11B 1 * DATE: N/A SIZE * + 1 1 0 0 0 1 1 0 1 0 1 0 7.5 2.5 10 5 MISO MOSI SCK CS# VREFB VREFA MISO MOSI SCK CS# VREFB VREFA TP13 TP12 IC NO. 1 LTC2758/2ACLX DEMO CIRCUIT 1684A 2/3/2011 DATE GND OUTA GND OUTB 02-03-11 SHEET 1 2 OF 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 6 JP16 FBA TP10 TP9 DUAL, SPI, IOUT, 18/16-BIT DAC TECHNOLOGY -2.5 -2.5 -10 -5 10 5 0 1 0 SPAN 0 0 0 * * * 6 U12 * * * U8 1206 V- V- V+ V+ 1206 C35 R27 - VR18 V- V+ V+ C28 + 0 2 3 - 0 * R30 R21 2 S2 S1 S0 * R29 R26 R20 * R10 * 3 MARK T. JP15 FBB APPROVED PRODUCTION 2 1 DESCRIPTION REVISION HISTORY REV TITLE: SCHEMATIC * __ ECO 7 1206 U11A * OPT. 1206 C24 APPROVALS C34 OPT * R25 OPT C27 * R9 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 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. OPT * * R23 R7 R6 VOSADJB R24 43 44 46 45 42 41 40 39 LTC6244HVCDD R22 V- V- V+ VOSADJA IOUT1A RFBA RFBA VOSADJB IOUT1B RFBB RFBB 3 Figure 3. DC1684A Dual, SPI, IOUT, 18-/16-Bit DAC 1K OPT R21 OPT R18 LTC2054HVCS5 LT1468CS8 * V+ U11C - + 100pF V+ U9,U13 +5V C31 6 U7 * 100pF VC22 V- V+ V+ LT1360CS8 U8, U12 GND EXT TP14 4.02K LT1012ACS8 U7, U14 2 JP12 R10 2 TP11 VOSADJA GND 0 VCC GEADJA JP11 OPT 1K OPT 10K OPT R9 LTC2752ACLX R8 21 23 24 25 22 19 26 20 11 13 12 14 EXT GND JP1 VOSADJA GND EXT TP15 VOSADJB CS# SCK MOSI MISO LTC2758ACLX OPT 1uF C25 OPT 10K R7 R11 10K ASSY * C39 0.1uF C38 0.1uF R12 10K JP13 R13 10K VOSADJB R14 10K NOTE: UNLESS OTHERWISE SPECIFIED -5V C36 0.1uF JP9 JP8 JP7 JP6 JP5 JP4 +5V 3 3 3 3 3 3 3 JP3 R15 10K VCC R16 10K D 2 2 2 2 2 2 2 R17 10K 1 3 1 3 GND 33 GEADJB 1 3 1 3 15 16 VDD GND GND GND GND GND GND 7 10 17 18 27 30 31 32 GEADJB IOUT2BF IOUT2BS IOUT2AF IOUT2AS 28 29 9 8 34 RINB RINB RINA RINA 5 6 7 4 RCOMA 3 GEADJA 4 RCOMB 35 36 REFB REFB 37 38 ROFSB ROFSB REFA REFA 2 1 ROFSA ROFSA 47 48 7 4 5 2 5 7 4 7 4 6 2 5 A B C D DEMO MANUAL DC1684A-A /DC1684A-B Schematic Diagrams dc1684aabfb 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. A B C CS# SCK EEVCC EESDA EESCL EEGND AUX CS SCK/SCL MOSI/SDA MISO V+ 5V 5 10 9 11 12 14 6 4 7 5 1 2 J1 HD2X7-079-MOLEX GND GND GND 13 8 3 D MOSI MISO T2 T1 TP7 TP16 C4 0.1uF SCL SDA WP A2 A1 A0 10.0K R33 10.0K R34 R32 10.0K D1 3 6 5 7 3 2 1 4 BAT54C 2 1 U4 24LC025-I /ST R5 4.99K V+ 10.0K R31 CS# SCK MOSI MISO 8 VCC VSS 4 R3 4.99K IN TP5 TP4 TP3 2 GND 4 ADJ OUT BYP 3 5 C6 10uF 1206 VIN U3 OPT. C16 10uF 1206 C12 10uF 1206 4 GND C13 10uF 1206 5 C17 10uF 1206 TRIM VOUT 6 OUTS OUTF 6 7 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. CUSTOMER NOTICE V- SD# VIN C5 10uF 1206 2 1 2 U2 LTC6655CHMS8-5 C19 10uF 1206 C15 10uF 1206 2 2 4 3 1 2 SCALE = NONE MARK T. JW APPROVALS C18 10uF 1206 C14 10uF 1206 C2 10uF 1206 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. D3 BAT54C C3 10uF 1206 V+ R2 10.0K R1 88.7K 12V D2 BAT54C 0.1uF Figure 4. DC1684A Dual, SPI, IOUT, 18-/16-Bit DAC AMPV- GND AMPV+ R4 4.99K C1 10uF 1206 1 U10 LT1761ES5-BYP C7 3 GND 3 GND 4 GND 5 GND 8 GND 1 2 GND OUT BYP BYP OUT 5 3 4 5 DATE: N/A SIZE -5V TECHNOLOGY 0.01uF C21 +5V VREFB 0.01uF C10 JP2 VREFB REF REG JP10 VCC 2 VCC VCC TP2 IC NO. 1 LTC2758/2ACLX DEMO CIRCUIT 1684A 2/3/2011 +5V SHEET 2 2 OF 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 C20 10uF 1206 C11 10uF 1206 VREFA 1 DUAL, SPI, IOUT, 18/16-BIT DAC TITLE: SCHEMATIC U6 LT1964ES5-5 IN SD SHDN IN U5 LT1761ES5-5 2 5V EXT VREFB TP6 2 JP14 VREFA 5V EXT VREFA TP1 1 3 1 3 4 2 3 1 1 3 2 1 3 5 A B C D DEMO MANUAL DC1684A-A /DC1684A-B Schematic Diagrams dc1684aabfb 7 DEMO MANUAL DC1684A-A /DC1684A-B 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 dc1684aabfb 8 Linear Technology Corporation LT 0314 REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2012