DEMO MANUAL DC573A LTC2400 24-Bit Micropower No Latency Delta Sigma ADC DESCRIPTION This demonstration board features the LTC®2400, a 24-bit high performance ΔΣ analog-to-digital converter (ADC). The LTC2400 combines exemplary DC accuracy (INL ±2ppm, 2.5μV offset, 0.3ppm noise) with an easy to use SPI interface in a SO-8 package. software to measure performance. The exposed ground planes allow proper grounding to prototype circuitry. After evaluating with LTC’s software, the digital signals can be connected to the end application’s processor/controller for development of the serial interface. DC573 is a member of Linear Technology’s QuikEval™ family of demonstration boards. It is designed to allow easy evaluation of the LTC2400 and may be connected directly to the target application’s analog signals while using the DC590 USB serial controller board and supplied Design files for this circuit board are available at http://www.linear.com/demo 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. BOARD PHOTO dc573af 1 DEMO MANUAL DC573A QUICK START PROCEDURE Connect DC573 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 evaluation software supplied with DC590 or downloaded from 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 averaged for the DVM display. dc573af 2 DEMO MANUAL DC573A HARDWARE SETUP JUMPERS JP1: Select the reference source, either external or 5V from the onboard LT1236 reference (default). JP2: Select the line rejection frequency, either 50Hz or 60Hz (default.) This jumper must be removed if applying an external conversion clock to the FO turret post. JP3: Trigger mode, either normal (default) or externally triggered. JP4: Trigger input signal. Pin 1 is a 5V logic signal, pin 2 is ground. When triggered mode is selected on JP3, a rising edge starts a new conversion. CONNECTION TO DC590 SERIAL CONTROLLER J1 is the power and digital interface connector. Connect to DC590 serial controller with supplied 14-conductor ribbon cable. ANALOG CONNECTIONS Analog signal connections are made via the row of turret posts along the edge of the board. Also, if you are 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. GND: Ground turrets are connected directly to the PCB’s ground planes. VCC: This is the supply for the ADC. Do not draw any power from this point. External power may be applied to this point after disabling the switching supply on DC590. If the DC590 serial controller is being used, the voltage must be regulated 5V only, as the isolation circuitry will also be powered from this supply. Refer to the DC590 quick start guide for more details. VREF: This turret is connected to the LTC2400 reference pin. If the onboard reference is being used, the reference voltage may be monitored from this point. An external ground referred reference may be connected to this terminal if JP1 is configured for external reference. VIN: Input voltage to the LTC2400. The absolute range of the input voltage is GND – 0.3V to VCC + 0.3V. The range for a valid conversion is GND – 0.125 • VREF to 1.125 VREF. See Figure 1. DC573a F01 Figure 1. LTC2400 Input Range dc573af 3 DEMO MANUAL DC573A EXPERIMENTS OFFSET Short VIN to ground. The offset is typically less than 0.5ppm of VREF, with a maximum of 2ppm of VREF (2.5μV typical and 10μV max when using a 5V reference.) FULL SCALE Short VIN to VREF. The full-scale error is typically less than 4ppm, with a maximum of 10ppm of VREF (20μV typical and 50μV max when using a 5V reference.) be set in the software options. With the input shorted to ground, the indicated noise is the noise of the LTC2400 input. When another source is connected, the indicated noise is the total noise of the LTC2400 and the source. The USB controller powers the LTC2400 from an LT1761 low noise regulator. Although this device has exceptionally low noise for a power regulator, it may still slightly elevate the noise floor of the LTC2400. For lowest noise operation, the LTC2400 may be powered from the onboard LT1236 reference by cutting the indicated trace and connecting VREF to VCC as shown in Figure 3. RMS NOISE Short VIN to ground. The RMS noise display indicates the RMS noise based on a number of samples that can DC573a F02 Figure 2. Proper Measurement Equipment Setup dc573af 4 DEMO MANUAL DC573A EXPERIMENTS DC573a F03 Figure 3. Low Noise Setup dc573af 5 DEMO MANUAL DC573A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 1 4 C1, C2, C6, C7 CAP, X7R 0.1μF 16V, 0603 AVX, 0603YC104MAT1A 2 1 C3 CAP, X5R 4.7μF 6.3V, 20%, 0805 TAIYO YUDEN, JMK212BJ475MGT 3 1 C4 CAP, X5R, 10μF 6.3V, 20%, 0805 TDK, C2012X5R0J106M 4 1 C5 CAP, X7R 0.01μF 16V 10%, 0603 AVX, 0603YC103KAT1A 5 7 E1 TO E7 TESTPOINT, TURRET, 0.064" MILL-MAX, 2308-2 6 3 JP1, JP2, JP3 JMP, 3PIN 1 ROW 0.079CC COMM-CON, 2802S-03-G1 7 3 SHUNTS FOR JP1, JP2, JP3 SHUNT, 0.079" CENTER COMM-CON CCIJ2MM-138G 8 0 JP4 JMP, HD1X2-079 OPT 9 1 J1 HEADER, 2 x 7PIN, 0.079CC MOLEX, 87331-1420 10 3 R1, R5, R6 RES, CHIP 4.99k 1/16W 1%, 0603 AAC, CR16-4991FM 11 1 R2 RES, CHIP 100 1/16W 5%, 0603 AAC, CR16-101JM 12 0 R3 RES, 0603 OPT 13 1 R4 RES, CHIP 10k 1/16W 5%, 0603 AAC, CR16-103JM 14 1 U1 IC, LTC2400CS8, SO8 LINEAR TECHNOLOGY, LTC2400CS8 15 1 U2 IC, LT1236ACS8-5, SO8 LINEAR TECHNOLOGY, LT1236ACS8-5 16 1 U3 IC, NC7SZ157P6X, SC70-6P FAIRCHILD SEMI, NC7SZ157P6X 17 1 U4 IC, NL17SZ74US, US8 ON SEMI, NL17SZ74US 18 1 U5 IC, 24LC025, TSSOP-8 MICROCHIP, 24LC025-I /ST dc573af 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. A B C GND VIN VREF VCC GND E5 E4 E3 E2 E1 5 C2 0.1UF 5V C4 10UF,6.3V 0805 VOUT 2 VIN VREF C5 0.01UF C3 4.7UF,6.3V 0805 4 3 2 1 8 7 6 5 VIN 2 NC 1 GND 4 NC 3 4 2. INSTALL SHUNT ON JP1-JP3 PIN 1 AND 2. 1. ALL RESISTORS ARE IN OHMS, 0603. ALL CAPACITORS ARE IN MICROFARADS, 0603. TRIG IN SDO 6 CS 5 FO 8 SCK 7 LTC2400CS8 GND VIN VREF VCC U1 LT1236ACS8-5 NC NC VOUT TRIM U2 NOTES: UNLESS OTHERWISE SPECIFIED VCC JP1 VREF 3 1 EXT JP4 OPT C6 0.1UF VCC R4 10K CP 3 2 D 1 CP VCC VCC Q 5 Q 3 3 50Hz 1 KIM T. DESIGNER: ENGINEER: MARK T. APPROVED: CHECKED: DRAWN: APPROVALS CONTRACT NO. JP3 NORMAL R2 100 60Hz JP2 REJECTION 3 1 TRIG MODE TRIGGERED Z 4 S 6 VCC 5 OPT NC7SZ157P6X 3 I0 1 I1 2 GND U3 R3 U4 NL17SZ74US C1 0.1UF 3 2 4 GND VCC 8 PR 7 4 1 2 CLR 6 2 D 5 2 DATE: A SIZE TITLE: 14 13 12 11 10 1 SHEET DC573A-1 * LTC2400CS8 Friday, March 21, 2003 DWG NO. 1 OF 1 A REV 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only HD2X7-079-MOLEX 14 13 12 11 10 9 9 7 7 8 8 5 5 6 6 J1 FO GND 24-BIT DELTA SIGMA ADC SCHEMATIC CS MISO 3 3 4 4 SCK E7 E6 VCC FO 1 1 1 2 2 V+ R1 R5 4.99K 4.99K 1% 1% R6 4.99K 1% TECHNOLOGY SCL 6 SDA 5 3 A2 4 VSS 24LC025 VCC 8 WP 7 C7 0.1UF U5 1 A0 2 A1 2 A B C D DEMO MANUAL DC573A SCHEMATIC DIAGRAM dc573af 7 DEMO MANUAL DC573A 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 dc573af 8 Linear Technology Corporation LT 0612 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2012