DEMO MANUAL DC1986A LTM2892-I I2C Module Isolator DESCRIPTION Demonstration circuit 1986A is an I2C Module(R) Isolator featuring the LTM2892-I. The demo circuit operates from external supply voltages on VCC1, VL1, VCC2, and VL2. It communicates all necessary signaling across the isolation barrier through LTC's IsolatorTM Module Technology. PERFORMANCE SUMMARY Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology, the Linear logo and Module are registered trademarks and Isolator is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25C SYMBOL PARAMETER VCC1, VCC2 Input Supply Range 3.0 5.5 V VL1, VL2 Logic Supply Range 3.0 5.5 V fMAX Maximum Data Rate VIORM Maximum Working Insulation Voltage CONDITIONS MIN TYP MAX UNITS INx OUTx, CL = 15pF 20 MHz I2C Communication 400 kHz GND1 to GND2 850 VDC Common Mode Transient Immunity 600 VRMS 50 kV/s OPERATING PRINCIPLES The LTM2892-I requires two to four external power supplies for operation, one for power and one for the signal interface, on each side of the isolation barrier. The logic supplies may be tied to the input supplies. Isolation is maintained by the separation of GND1 and GND2 where significant operating voltages and transients can exist without affecting the operation of the LTM2892-I. The ON1 and/or ON2 pins enable or shut down the LTM2892-I, both must be driven to their respective logic supply voltage for proper operation. All I2C or digital signals are referenced to the logic supply pins VL1 or VL2. I2C signaling does not require any additional components. The demo board includes pull-up resistors on SDA1 and SCLIN. SCLOUT and SDA2 do not require external pull-ups, SCLOUT is a push-pull output and SDA2 is pulled high through an integral current source within the LTM2892-I. Do not use external pull-up resistors or current sources on SCLOUT or SDA2. I2C signaling is configured by defining the LTM2892-I pins as follows: Logic Side: SCLIN = SCL(IN), and SDA1 = SDA(IN). Isolated Side: SCLOUT = SCL(OUT), SDA2 = SDA(OUT). Reference Figure 1 for schematic representation. No special precautions are required for low RF emissions. EMI performance is shown in Figure 2, measured using a gigahertz transverse electromagnetic (GTEM) cell and method detailed in IEC 61000-4-20, Testing and Measurement Techniques - Emission and Immunity Testing in Transverse Electromagnetic Waveguides. dc1986af 1 DEMO MANUAL DC1986A OPERATING PRINCIPLES LTM2892-I SCLIN SDA1 INA SCL(IN) SDA(IN) VCC2 VL2 ON2 ISOLATION BARRIER VCC1 VL1 ON1 5V OUTB SDA1 OUTC SCLOUT SDA2 OUTA 5V SCL(OUT) SDA(OUT) INB SDA2 INC GND1 GND2 dc1986a F01 NOTE: INA, INB AND INC ARE OPTIONAL CONNECTIONS Figure 1. I2C Operation 60 DETECTOR = PEAK HOLD RBW = 120kHz VBW = 300kHz SWEEP TIME = 680ms, 10 SWEEPS NUMBER OF POINTS = 501 50 40 30 dBV/m 20 10 0 -10 -20 CISPR 22 CLASS B LIMIT DUT -30 0 100 200 300 400 500 600 FREQUENCY (MHz) 700 800 900 1000 dn1986a F02 Figure 2. DC1986A Radiated Emissions dc1986af 2 DEMO MANUAL DC1986A QUICK START PROCEDURE Demonstration circuit 1986A is easy to set up and evaluate the performance of the LTM2892-I. Refer to Figure 3 for proper measurement equipment setup and follow the procedure below. NOTE: When measuring the input or output voltage ripple or high speed signals, care must be taken to avoid a long ground lead on the oscilloscope probe. 1. Install jumpers as shown in Figure 3 and the schematic diagram. 2. With power off, connect the input power supplies to VCC1 - GND1 and VCC2 - GND2 as shown. 3. Turn on the power at the input. NOTE: Make sure that the input voltage does not exceed6V. 4. Configure jumpers or connect signals to turrets as appropriate. If a signal is connected to an input channel turret the associated channel jumper must be removed for proper operation. Figure 3. Demo Board Setup dc1986af 3 DEMO MANUAL DC1986A PCB LAYOUT Top Copper Bottom Copper PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER I.C., LTM2892CY-I LINEAR LTM2892CY-I#PBF Required Circuit Components 1 1 U1 Hardware: For Demo Board Only 2 4 C1-4 CAP., TANT 4.7F 10V 20% 0805 NICHICON F921A475MPA 3 12 E4-15 TURRET, 0.065" MILL-MAX 2308-2-00-80-00-00-07-0 4 6 E1-3, E16-18 TURRET, 0.095" MILL-MAX 2501-2-00-80-00-00-07-0 5 2 JP3-4 2mm SINGLE ROW HEADER, 2 X 1 PIN SAMTEC TMM-102-02-L-S 6 5 JP1-2, JP5-7 2mm SINGLE ROW HEADER, 3 x 1 PIN SAMTEC TMM-103-02-L-S 7 7 JP1-7 2mm SHUNT SAMTEC 2SN-BK-G 8 2 R1-R2 RES., CHIP 4.7k 5% 0805 VISHAY CRCW08054K70JNEA 9 5 R3-R7 RES., CHIP 100 5% 1206 AAC CR18-101JM dc1986af 4 DEMO MANUAL DC1986A SCHEMATIC DIAGRAM dc1986af 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. 5 DEMO MANUAL DC1986A 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 (c) 2004, Linear Technology Corporation dc1986af 6 Linear Technology Corporation LT 0912 * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear.com (c) LINEAR TECHNOLOGY CORPORATION 2012