Precision Instrumentation Amplifier Evaluation Board AD8224-EVALZ FEATURES GENERAL DESCRIPTION Two AD8224 circuits Dual channel Differential output Easy to connect screw terminals Decoupled supply lines Pads for RFI filtering The AD8224-EVALZ has two AD8224 instrumentation amplifier circuits: one circuit is configured for dual-channel operation, and the other is configured for single-channel, differential output operation. The inputs, outputs, references, and supplies are routed to screw terminals for easy connectivity. The PCB board has four layers. The top and bottom layers are used for routing, and the two internal layers are ground planes. The ground plane was removed underneath the RG resistors. This is a precaution against any capacitance mismatch at the RGx pins that may affect ac CMRR. 06687-003 AD8224 EVALUATION BOARD Figure 1. Rev. 0 Evaluation boards are only intended for device evaluation and not for production purposes. Evaluation boards as supplied “as is” and without warranties of any kind, express, implied, or statutory including, but not limited to, any implied warranty of merchantability or fitness for a particular purpose. No license is granted by implication or otherwise under any patents or other intellectual property by application or use of evaluation boards. Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Analog Devices reserves the right to change devices or specifications at any time without notice. Trademarks and registered trademarks are the property of their respective owners. Evaluation boards are not authorized to be used in life support devices or systems. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2007 Analog Devices, Inc. All rights reserved. AD8224-EVALZ EVALUATION BOARD HARDWARE SETTING THE GAIN JUMPER SETTINGS Table 1. Jumper J1A, J1B, J11 J2A, J2B, J12, J13 Purpose Connect inputs together Connect reference pins to ground Default Unconnected Connected Table 2. In the default factory setting, the reference pins of the AD8224 are connected to GND through J2A, J2B, J12, and J13. These jumpers also connect to W2A:REF1, W2B:REF2, W13:REF2, and W13:+IN2. Therefore, in the shipping configuration, W2A:REF1, W2B:REF2, W13:REF2, and W13:+IN2 are connected to GND. To disconnect the terminal from GND, remove the corresponding jumper. QUICK START Channel Dual Channel A Dual Channel B Differential Output Channel Component R1A R1B R11A EMI FILTERING The board comes with 0603 component pads for an EMI filter. These components are shown in Table 3. Table 3. The quick start feature assumes that the jumpers are in their default factory positions. To begin: 1. 2. 3. 4. 5. The gain setting resistors are R1A and R1B for the dual-channel part and R11A for the differential output part. The pads are sized for 0603-sized resistors, although 0402 and 0805 sizes can also be used. Connect a ground lead to GND. Connect a +15 V supply to +VS. Connect a −15 V supply to −Vs. Ground −IN1. Connect a 1 V p-p, 1 kHz source signal to +IN1. A replica of the signal should now appear at OUT1. Channel Dual Channel A Dual Channel B Differential Output Channel Component R3A, R2A, C1A, C2A, C3A R3B, R2B, C1B, C2B, C3B R13, R12, C11, C12, C13 The board, as shipped, does not contain EMI filtering. The resistors pads are populated with 0 Ω resistors, and the capacitors are not populated. See the AD8224 data sheet for more information on EMI filtering. Rev. 0 | Page 2 of 4 AD8224-EVALZ EVALUATION BOARD SCHEMATICS REF1 OUT1 OUT2 REF2 W2A W2B REF_A C4 0.1µF +VS REF_B J2A –VS 16 +IN1 14 13 C2A* 1 12 2 11 –IN2 R1A* R1B* 3 R2A 0Ω AD8224 W1A 5 +VS +IN2 R3B 0Ω 9 W1B DUAL C3A* J1B C2B* 10 4 R2B 0Ω C3B* 6 7 8 C5 0.1µF REF_A 06687-001 J1A 15 C1B* R3A C1A* 0Ω –IN1 J2B REF_B –VS *NOT POPULATED Figure 2. AD8224 Evaluation Board Schematic—AD8224 Dual Channel +OUT –OUT W12 R10 10kΩ C14 0.1µF +VS C10 100pF –VS 16 –IN1 C12* J11 +IN1 R12 0Ω W11 15 14 13 AD8224 R13 C11* 0Ω DIFF OUT 1 12 2 11 3 10 4 9 R11B* R11A* W13 +IN2 C13* REF2 5 6 7 8 C15 0.1µF +VS J13 *NOT POPULATED –VS J12 + + C8 10µF +VS GND1 GND2 GND3 GND4 –VS W6 W5 +VS 06687-002 C7 10µF –VS Figure 3. AD8224 Evaluation Board Schematic—AD8224 Differential Output Rev. 0 | Page 3 of 4 AD8224-EVALZ ORDERING INFORMATION ORDERING GUIDE Model AD8224-EVALZ1 1 ESD CAUTION Description Evaluation Board Z = RoHS Compliant Part. ©2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. EB06687-0-3/07(0) Rev. 0 | Page 4 of 4