Precision Instrumentation Amplifier Evaluation Board AD8222-EVALZ FEATURES Two AD8222 circuits Dual channel Differential out Easy to connect screw terminals Decoupled supply lines Pads for RFI filtering GENERAL DESCRIPTION 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 two RG pins, which may affect ac CMRR. JUMPER SETTINGS Purpose Connect inputs together Connect reference pins to ground Figure 1. AD8222-EVALZ Evaluation Board Photo SETTING THE GAIN 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. EMI FILTERING Table 1. Jumpers J1A, J1B, J11 J2A, J2B, J12, J13 06386-001 The AD8222-EVALZ has two AD8222 instrumentation amplifier circuits: one circuit is configured for dual-channel operation, while the other is configured for single-channel, differential output operation. Inputs, outputs, references, and the supplies are routed to screw terminals for easy connectivity. Default Unconnected Connected In the default factory setting, the reference pins of the AD8222 are connected to GND through J2A, J2B, J12, and J13. 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 The quick start feature assumes that the jumpers are in their factory default positions. The board comes with 0603 component pads for an EMI filter. These components are shown in Table 2. Table 2. Channel Dual Channel A Dual Channel B Differential Output Channel Components 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 AD8222 data sheet for more information on EMI filtering. To begin: • Connect ground lead to GND. • Connect a 15 V supply to +VS. • Connect a −15 V supply to −Vs. • Ground −IN1. • Connect a 1V p-p, 1 kHz source signal to +IN1. A replica of the signal should now appear at OUT1. Rev. 0 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. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. 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 ©2006 Analog Devices, Inc. All rights reserved. AD8222-EVALZ REF1 OUT1 OUT2 REF2 W2A W2B REF_A REF_B J2A C4 0.1µF C1A SPARE R3A 0Ω –IN1 C2A SPARE R2A 0Ω +IN1 –V 15 16 R1A SPARE J1A J2B +V 14 C1B SPARE R2B 0Ω 13 1 12 2 11 3 10 4 9 AD8222 W1A 6 5 7 +V REF_A 8 +IN2 W1B C3B SPARE DUAL C3A SPARE –IN2 C2B J1B SPARE R3B 0Ω R1B SPARE C5 0.1µF REF_B –V +OUT –OUT W12 +V R10 10kΩ C14 0.1µF –V C11 SPARE R13 0Ω C12 SPARE –IN J11 R12 0Ω +IN 15 16 14 13 AD8222 1 12 DIFF OUT 11 2 R11A SPARE C10 100pF R11 SPARE 3 W13 10 4 +IN2 9 W11 C13 SPARE 5 6 7 +V 8 C15 0.1µF REF2 J13 –V J12 C7 10µF +V C8 10µF –V W5 +V 06386-002 W6 GND1 GND2 GND3 GND4 –V Figure 2. AD8222-EVALZ Evaluation Board Schematic ESD CAUTION ORDERING GUIDE Model AD8222-EVALZ 1 1 Z = Pb-free part. ©2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. EB06386-0-11/06(0) Rev. 0 | Page 2 of 2 Description Evaluation Board