DEMO MANUAL DC1490B LTC2460: 16-Bit, Differential, D∑ ADC with SPI Interface DESCRIPTION Demonstration circuit 1490B features the LTC2460, a 16‑bit high performance Δ∑ analog-to-digital converter (ADC) with an SPI interface. The input is unipolar with a range of 0-REF. The modulator’s proprietary sampling technique reduces the average input current to less than 50nA – or‑ ders of magnitude lower than typical delta sigma ADCs. DC590 USB Serial Controller board and supplied software to measure performance. The exposed ground planes allow proper grounding to prototype circuitry. After evaluating with Linear Technology’s software, the digital signals can be connected to the end application’s processor/controller for development of the serial interface. DC1490B is a member of Linear Technology’s QuikEval™ family of demonstration boards. It is designed to allow easy evaluation of the LTC2460 and may be connected directly to the target application’s analog signals while using the Design files for this circuit board are available at www.linear.com/demo/1490 L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and QuikEval is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. RIBBON CABLE TO DC590 CONTROLLER INPUT Figure 1. Proper Measurement Equipment Setup dc1490bfa 1 DEMO MANUAL DC1490B QUICK START PROCEDURE Connect DC1490B to a DC590 USB Serial Controller using the supplied 14 conductor ribbon cable. Connect DC590 to host PC with a standard USB A/B cable. Run the evalu‑ ation software supplied with DC590 or downloaded from http://www.linear.com/software. The correct program will be loaded automatically. Click the COLLECT button to start reading the input voltage. Details on software features are documented in the control panel’s help menu. Tools are available for logging data, changing reference voltage, changing the number of points in the strip chart and histogram, and changing the number of points aver‑ aged for the DVM display. Figure 2. Software Screenshot HARDWARE SET-UP Connection to DC590 Serial Controller J1 is the power and digital interface connector. Connect to DC590 serial controller with supplied 14 conductor ribbon cable. GND: This turret is connected directly to the internal ground planes. VCC: This is the supply and reference voltage for the ADC. Do not draw any power from this point. IN: This is the input to the ADC Analog Connections Analog signal connections are made via the row of turret posts along the edge of the board. Also, when connecting the board to an existing circuit the exposed ground planes along the edges of the board may be used to form a solid connection between grounds. REFOUT: This turret is connected to the LTC2460 REFOUT pin. This pin may be used to provide a reference voltage to an external circuit and can source up to 100µA. Do NOT drive this pin. PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 5 C1, C2, C3, C4, C5 Capacitor, 0402 0.1µF 20% 16V X7R TDK C1005X7R1C104M 2 1 C6 Capacitor, 0603 10µF 20% 6.3V X5R Murata GRM188R60J106ME47D 3 4 E1, E2, E3, E4 Turret Mill Max 2308-2 4 1 J1 Header, 2X7 2mm Molex 87331-1420 5 1 R1 Resistor, 0402 1kΩ 5% 1/16W Vishay CRCW0402102JNED 6 3 R2, R3, R4 Resistor, 0402 4.99kΩ 1% 1/16W Vishay CRCW04024K99FKED 7 1 U1 IC, 16-Bit ADC with Integrated Precision Reference Linear Tech. LTC2460CDD 8 1 U2 IC, IC Serial EEPROM 2k Microchip Tech. 24LC025-I/ST dc1490bfa 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. A B C IN REFOUT GND VCC E1 E2 E4 E3 C3 5 R1 1K 0.1uF VCC 0.1uF C2 9 IN LTC2460CDD U1 4 0.1uF C1 1 REFOUT D VCC REF- 2 COMP 12 VCC 13 11 GND 10 GND 7 GND GND 8 3 L.Chen 3 Wednesday, October 29, 2008 DESIGNER ENGINEER APPROVED CHECKED `\ APPROVALS DRAWN 1% DATE A0 A1 A2 WP SCL 5 1% R4 4.99K 0.1uF C5 VCC TECHNOLOGY U2 24LC025-I/ST SDA 2 NC EEGND EESDA EEVCC EESCL MISO MOSI/SDA SCK/SCL CS 5V VUNREG 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 14 12 9 10 11 5 7 4 6 2 1 J1 1 SCALE: DWG NO 2 FILENAME: 1490B-1.DSN SIZE CAGE CODE SHEET DC1490B 1 1 OF SCH, LTC2460CDD, 16-BIT DELTA SIGMA SPI ADC TITLE 1 2 3 7 6 CS SCK SDI SD0 R3 4.99K CONTRACT NO. 1% R2 4.99K 10uF 0.1uF SCK 5 4 SDI 6 SDO CS C6 C4 3 8 4 GND 3 5 GND 8 VCC GND 4 GND 13 This circuit is proprietary to Linear Technology and supplied for use with Linear Technology parts. Customer Notice: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 Applications Engineering for assistance. 1 1 REV A B C D DEMO MANUAL DC1490B SCHEMATIC DIAGRAM dc1490bfa 3 DEMO MANUAL DC1490B 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 direc‑ tive 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 applica‑ tion engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation dc1490bfa 4 Linear Technology Corporation LT 0115 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 2010