EVAL-INAMP-82RMZ - Analog Devices

Evaluation Board User Guide

UG-261

One Technology Way • P. O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.com

Evaluation Boards for the AD62x Series and the AD822x Series

Instrumentation Amplifiers

PLEASE SEE THE LAST PAGE FOR AN IMPORTANT

WARNING AND LEGAL TERMS AND CONDITIONS. Rev. C | Page 1 of 8

FEATURES

3 generic, easy-to-use evaluation boards

Shipped with an assortment of Analog Devices, Inc., in-amps

Solder in the in-amp to be tested

Test pins already populated

Decoupling capacitors already populated

EVAL-INAMP-62RZ board

Compatible with AD620, AD621, AD622, AD623, AD627,

AD8223, and AD8225 in SOIC or PDIP

EVAL-INAMP-82RZ board

Compatible with AD8221, AD8226, AD8227, AD8228,

AD8229, AD8421, AD8428, and AD8429 in SOIC package

EVAL-INAMP-82RMZ board

Compatible with AD8220, AD8221, AD8226, AD8227,

AD8228, AD8236, and AD8421 in MSOP package

09753-001

Figure 1.

GENERAL DESCRIPTION

This user guide describes three generic evaluation boards that

can be used to evaluate many of Analog Devices instrumentation

amplifiers. For information on the performance of a specific

instrumentation amplifier, see the data sheet for that

instrumentation amplifier.

EVAL-INAMP-62RZ (SOIC or PDIP)

The EVAL-INAMP-62RZ is designed for evaluation of

instrumentation amplifiers in the legacy pinout. This board

can be used to evaluate the AD620, AD621, AD622, AD623,

AD627, AD8223, and AD8225 instrumentation amplifiers. In

addition to the basic in-amp connection, circuit options enable

the user to adjust the offset voltage, apply an output reference,

or provide shield drivers with user-supplied components. The

board is shipped with an assortment of instrumentation amplifier

ICs in the legacy SOIC pinout, typically AD620, AD621, AD622,

AD623, AD8223, and AD8225. The board also has an alternative

footprint for a through-hole, 8-lead PD I P.

EVAL-INAMP-82RZ (SOIC)

The EVAL-INAMP-82RZ is designed for evaluation of

instrumentation amplifiers in the high performance pinout.

This board can be used to evaluate the AD8221, AD8226,

AD8227, AD8228, AD8229, AD8421, AD8428, and AD8429

in SOIC packages. The board is shipped with an assortment of

instrumentation amplifier ICs in the high performance SOIC

pinout, typically AD8221, AD8226, AD8421, AD8428, and

AD8429. The evaluation board is arranged so that users can

easily solder on the gain resistor. The in-amp reference pin can

be connected to ground through a solder short or connected to

the user’s source through the test pin. A small prototyping area

allows interfacing to another part in an SOIC package.

Users can add their own SMA or SMB connector to interface

the evaluation board with complementary tools, such as an

analog-to-digital converter (ADC) evaluation board, available

from Analog Devices.

EVAL-INAMP-82RMZ (MSOP)

The EVAL-INAMP-82RMZ board is exactly the same as the

EVAL-INAMP-82RZ board, except that is designed for the

MSOP pinout. This board can be used to evaluate the AD8220,

AD8221, AD8226, AD8227, AD8228, AD8236, and AD8421 in

MSOP packages. The EVAL-INAMP-82RMZ board ships with

an assortment of in-amp ICs in the high performance MSOP

pinout, typically AD8220, AD8221, AD8226, AD8228, and

AD8421.

UG-261 Evaluation Board User Guide

Rev. C | Page 2 of 8

TABLE OF CONTENTS

Features .............................................................................................. 1

General Description ......................................................................... 1

Revision History ............................................................................... 2

E VA L-INAMP-62RZ Details ........................................................... 3

Quick Start for the EVAL-INAMP-62RZ Board .......................... 4

Circuit Options ............................................................................. 4

Load Resistor ................................................................................. 4

CMRR Performance ..................................................................... 4

Guard Drivers ................................................................................5

Component Locations ..................................................................5

User Options ..................................................................................6

Quick Start for the EVAL-INAMP-82RZ and EVAL-INAMP-

82RMZ Boards ...................................................................................7

Reference ........................................................................................7

Output .............................................................................................7

REVISION HISTORY

6/12—Rev. B to Rev. C

Changes to Features Section, EVAL-INAMP-62RZ (SOIC or

PDIP) Section, E VA L -INAMP-82RZ (SOIC) Section, and

E VA L-INAMP-82RMZ (MSOP) Section ...................................... 1

Changes to Quick Start for the EVAL-INAMP-82RZ and

EVAL-INAMP-82RMZ Boards Section ........................................ 7

3/11—Rev. A to Rev. B

Changed Format to User Guide ................................... Throughout

Changes to Document Title ............................................................ 1

Changes to Features Section............................................................ 1

Deleted Applications Section .......................................................... 1

Changes to General Description Section ...................................... 1

Added CMRR Performance Section .............................................. 4

Added Component Locations Section ........................................... 5

11/08—Rev. 0 to Rev. A

Combined AD623-EVALZ Data Sheet and AD623-EVA L

Data Sheet ............................................................................ Universal

Added AD8220/AD8221-EVAL Z .............................. Throughout

Changed AD623-EVALZ to AD620 Series-E VA L Z ........ Throughout

Changes to General Description ..................................................... 1

Added EVAL-INAMP-62RZ Details Section ................................. 3

Added Quick Start for the EVAL-INAMP-62RZ Boards Section ..... 4

Changes to Gain Adjustment Section ............................................. 4

Added Table 1 and Table 2; Renumbered Sequentially ................ 4

Changed Appendix Heading to User Options ............................... 6

Added Quick Start for the EVAL-INAMP-82RZ Section and

E VA L-INAMP-82RMZ Boards Section ......................................... 7

Changes to Ordering Guide ............................................................. 8

12/07—Revision 0: AD623-EVALZ Initial Version

6/03—Revision 0: AD623-EVAL Initial Version

Evaluation Board User Guide UG-261

Rev. C | Page 3 of 8

EVAL-INAMP-62RZ DETAILS

W15

OUTPUT

REF

6OUTPUT

EXT_REF

OFFSET ADJ.

OP177

W13

W11

W12

1W8

W10

GND2

+IN

+GUARD

–GUARD

–IN

GND1

W14

100Ω

REMO V E W3 AND W 4 FO R AC COUPLING.

C1, 0. 1µF

AUX

0.1µF

0.1µF –V

AUX

100kΩ

C3, 0. 1µF

–R

–V

0.1µF

0.1µF C10

0.1µF

AUX

–V

AUX

–V

AUX

0.1µF

OP177

CS2

J500

240µA

CS2

J500

240µA

5.9kΩ, 1%

R10

5.9kΩ, 1%

100kΩ

0.1µF

NOTES

INSTALL FOR AC COUPLING ONLY.

TO US E GUARD DRI V E R, I NS TAL L R5 AND R6

INSTEAD OF R

. R5 AND R6 = 0.5R

C12

10µF

25V

C11

10µF

25V

GND

–V

AUX

–V

COMP ONENTS IN SHADE D ARE AS

ARE USER SUPPLIED.

–

AD708J

09753-002

Figure 2. EVAL-INAMP-62RZ (AD62x Series) Schematic Diagram

UG-261 Evaluation Board User Guide

Rev. C | Page 4 of 8

QUICK START FOR THE EVAL-INAMP-62RZ BOARD

CIRCUIT OPTIONS

Single-Supply Operation

A jumper is provided to select between single or dual power

supplies. The evaluation board is shipped with W14 in the dual-

supply position. To convert to single supply, place W14 in the

position marked with a ground symbol.

Gain Adjustment

The gain of the AD621 is pin selectable where G = 1 (default) or

G = 100 (strap Pin 1 and Pin 8). In contrast, the gain of the AD620,

AD622, and AD623 devices is resistor dependent (the resistor is

connected between the RG pins). Without a resistor, the gain is

unity. Table 1 to Table 3 provide calculated gains for each device.

See the individual product data sheet for the gain equations.

Table 1. AD620 Gain Resistor Values

1% Standard

Value of RG (Ω)

Calculated

Gain

0.1% Standard

Value of RG (Ω)

Calculated

Gain

49.9 k 1.990 49.3 k 2.002

12.4 k

4.984

12.4 k

4.984

5.49 k 9.998 5.49 k 9.998

2.61 k 19.93 2.61 k 19.93

1.00 k 50.40 1.01 k 49.91

499 100.0 499 100.0

249 199.4 249 199.4

100 495.0 98.8 501.0

49.9 991.0 49.3 1003.0

Table 2. AD622 Gain Resistor Values

Desired Gain 1% Standard Value of RG (Ω) Calculated Gain

2 51.1 k 1.988

5 12.7 k 4.976

10 5.62 k 9.986

20 2.67 k 19.91

33 1.58 k 32.96

40 1.3 k 39.85

50 1.02 k 50.50

65 787 65.17

100 511 99.83

200 255 199.0

500 102 496.1

1000 51.1 989.3

Table 3. AD623 Gain Resistor Values

Desired Gain

1% Standard Value of RG (Ω) Calculated Gain

2 100 k 2

24.9 k

5.02

10 11 k 10.09

20 5.23 k 20.12

33 3.09 k 33.36

40 2.55 k 40.21

50 2.05 k 49.78

65 1.58 k 64.29

100 1.02 k 99.04

200 499 201.4

500 200 501

1000 100 1001

External Reference or Offset Adjustment

When shipped, the reference of the EVAL-INAMP-62RZ board

is connected to ground. Certain single-supply applications (for

example, an ADC connected to the output of the in-amp) require a

symmetrical output voltage centered on a nonzero value. The

reference can be equal to half the supply, or an application-specific

voltage can be provided by an ADC. The user can install a jumper

at W13 and connect an external reference to the EXT_REF pin.

To maintain proper operation of the in-amp, the reference

should be provided by a voltage source.

Similarly, a provision is made for an offset adjustment of ±1.12 V

by installing the parts listed in Table 6. Although the A2 and A3

ICs can be used with a single or dual power supply connection,

A1 requires a dual supply. To enable the offset feature, install a

shunt in Position W11. To adjust the offset of the in-amp,

ground both inputs and measure the output voltage. Adjust

Potentiometer R1 for 0 V.

LOAD RESISTOR

Although not required for normal operation, a load resistor can

be inserted at Position R8.

CMRR PERFORMANCE

The AD621 CMRR performance degrades at gains of 100 when

using this board due to the high performance of the AD621.

Evaluation Board User Guide UG-261

Rev. C | Page 5 of 8

GUARD DRIVERS

When interference from sources such as power lines must be

reduced to levels below those provided by standard shielded

cables, guard drivers may be effective. A guard equalizes the ac

potential between the in-amp input and the cable shield of the

line, effectively reducing the low frequency interference voltage.

A2 in Figure 3 is a dual op amp AD708 driving the shield(s) of

the input cable(s) from the gain resistor pins of the in-amp. The

voltages at these pins are equal to the input voltages plus 0.6 V

(see the device data sheet).

The E VA L -INAMP-62RZ provides single and differential guards.

Differential guards drive the shields with essentially the same

signals as the inputs, whereas the single guard can be used for

dual conductor cables. In this mode, the +GUARD drives the

shield at ½(VIN DIFF) + 0.6 V.

To activate the guard drivers, +VAUX and −VAUX must be connected.

For shielded cables at both inputs, install the W1, W2, W5,

and W8 jumpers.

Using a Single Guard

When using the AD620, AD622, and AD623 for gains greater

than 1, install Resistors R6 and R11 (which are each half the

calculated resistance of RG) and Jumpers W1, W2, and W10.

For a gain of 1, either Position R6 or Position R11 can be shorted

to enable the guard driver input. Connect the shield to +GUARD.

On the header pins that do not bear the ground symbol, insert a

shunt across Position W1.

The guard drivers can be assembled using the components

listed in Table 6.

COMPONENT LOCATIONS

Figure 3 shows the component layout and the location of

connections for the EVAL-INAMP-62RZ board.

INPUT

OUTPUT

POWER

09753-003

Figure 3. Component Location for the EVAL-INAMP-62

UG-261 Evaluation Board User Guide

Rev. C | Page 6 of 8

USER OPTIONS

Table 4. Jumpers

Jumper Function Description Status

+GUARD select

Allows the shield of the positive input cable to be connected to the guard driver or ground.

Not installed

W2 −GUARD select Allows the shield of the negative input cable to be connected to the guard driver or ground. Not installed

W3 +Input coupling Installed; the positive input is dc-coupled. Installed

W4 −Input coupling Installed; the negative input is dc-coupled. Installed

W5 Guard driver −IN Connects the negative shield guard driver to Pin 1 of the in-amp. Not installed

W6 −VS to − VAUX Connects the negative supply voltage to the negative auxiliary voltage of the same value. Not installed

W7 +VS to + VAUX Connects the positive supply voltage to the positive auxiliary voltage of the same value. Not installed

W8 Guard driver +IN Connects the positive shield guard driver to Pin 8 of the in-amp. Not installed

W9 Guard driver +IN Connects the positive shield guard driver to ground. Not installed

W10 Guard driver +IN Selects the single-shield guard driver. Not installed

W11 Reference input Connects the reference of the in-amp to the offset-adjustable voltage reference. Not installed

W12 Reference input Connects the reference of the in-amp to ground. Installed

W13 Reference input Connects the reference of the in-amp to an external reference supply. Not installed

W14 In-amp −VS source Connects the in-amp −VS pin to GND or to −VS of the evaluation board. Connected to −VS

W15 Guard driver −IN Connects the negative shield guard driver to ground. Not installed

Table 5. Input/Output

I/O Function

+VS/−VS Positive and negative rails of the in-amp.

GND Ground for the board. GND1, GND2, GND3, and GND4 designate pins.

+IN/−IN

Positive and negative inputs of the in-amp.

+GUARD/−GUARD Positive and negative terminals for use with a shielded cable.

EXT_REF External reference input for the in-amp.

OUTPUT Output of the in-amp.

+VAUX/−VAUX Auxiliary power rails for guard drivers and offset reference circuitry.

Table 6. User-Supplied Parts for Guard and Offset Circuits

Reference Designation Part

Guard Drivers

C5, C6

0.1 µF, 25 V ceramic capacitor

A2 AD708JN dual precision op amp

Offset Regulators

C7 to C10 0.1 µF, 25 V ceramic capacitor

A1 OP177 precision op amp

CS1, CS2 J500 240 µA current source

R9, R10 5.9 kΩ, 1% metal film resistor

Evaluation Board User Guide UG-261

Rev. C | Page 7 of 8

QUICK START FOR THE EVAL-INAMP-82RZ AND EVAL-INAMP-82RMZ BOARDS

The quick start instructions in this section assume that the

evaluation board is in default condition as shown in Table 7.

This section describes two separate evaluation boards, where

the EVAL-INAMP-82RZ has an SOIC footprint and the

EVAL-INAMP-82RMZ has an MSOP footprint.

Table 7. Factory Setting

Connection Purpose

W1 is soldered. REF is tied to ground.

Follow Step 1 through Step 3 to get started using these boards

(see Figure 4).

1. Connect a ±2.3 V to ±15 V supply to +VS and −VS. (Consult

the specific data sheet for power supply operating range.)

2. Drive the inputs with a signal.

3. Measure the output on a multimeter or oscilloscope. The

output voltage is the voltage measured between VOUT (OUT)

and VREF (REF). The output can drive another device, such

as an ADC.

10µF0.1µF

10µF 0.1µF

+VS

–VS

+IN +IN 48+VS

5–VS

7 VOUT

6 VREF

–IN 1

RG3

RG2

–IN

REF

OUT

R1 DUT

–

SMA/SMB

CONNECTOR

(OPTIONAL)

09753-004

Figure 4. EVAL-INAMP-82RZ Schematic

REFERENCE

The reference level of the instrumentation amplifier can be set

by driving the REF pin with a precision voltage reference or by

using the solder jumper, W1. By default, W1 is soldered, shunting

REF to ground. If a reference voltage other than ground is used,

the solder must be removed from W1 before driving REF with

the reference voltage, as shown in Figure 5.

+IN

–IN

REF

OUT

10V

10µF0.1µF

10µF 0.1µF

DUT

–

1V p - p, 1kHz

–V

OSCILLOSCOPE

+COM

09753-005

Figure 5. Using an External Voltage Source to Set the

Reference Level (Circled) Input

Do not leave the in-amp inputs floating, that is, without a dc

return path. This often occurs when the inputs are connected to

a transformer, a thermocouple, or a pair of series capacitors.

The inputs should have a dc path to ground, as shown in Figure 5

and Figure 6.

The circuit shown in Figure 6 has series capacitors, C1 and C2,

between the signal generator and the input. The series capacitors

prevent a dc current from flowing into the input transistors of

the instrumentation amplifier. Two matched 10 kΩ resistors are

used between the instrumentation amplifier inputs and ground

to provide the necessary current path. Closely match these

resistors to reduce offset and CMRR errors.

OSCILLOSCOPE

+COM

REF

OUT

+15V 10µF

–15V

0.1µF

10µF 0.1µF

DUT

–

+VS

–VS

499Ω

10kΩ 10kΩ

+IN

–IN

09753-006

Figure 6. AC Input Coupling Using a Resistive DC Return Path

OUTPUT

Output measurements should be made by monitoring the voltage

between the OUT and REF tie points of the board, as shown in

Figure 7. If an external voltage reference is used, the output can

be measured, referred to ground, as shown in Figure 5. The

evaluation board offers an SMA/SMB outline. By default, the

output voltage measured using an SMA/SMB connector is with

respect to ground.

REF

OUT

+15V 10µF

–15V

0.1µF

10µF 0.1µF

DUT

–

500mV p- p,

100Hz

10V p- p,

10Hz

–V

OSCILLOSCOPE

+COM

5.49kΩ

+IN

–IN

09753-007

Figure 7. Correct Output Connection Using the REF Pin

UG-261 Evaluation Board User Guide

Rev. C | Page 8 of 8

NOTES

ESD Caution

ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection

circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality.

Legal Terms and Conditions

By using the evaluation board discussed herein (together with any tools, components documentation or support materials, the “Evaluation Board”), you are agreeing to be bound by the terms and conditions

set forth below (“Agreement”) unless you have purchased the Evaluation Board, in which case the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not use the Evaluation Board until you

have read and agreed to the Agreement. Your use of the Evaluation Board shall signify your acceptance of the Agreement. This Agreement is made by and between you (“Customer”) and Analog Devices, Inc.

(“ADI”), with its principal place of business at One Technology Way, Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement, ADI hereby grants to Customer a free, limited, personal,

temporary, non-exclusive, non-sublicensable, non-transferable license to use the Evaluation Board FOR EVALUATION PURPOSES ONLY. Customer understands and agrees that the Evaluation Board is provided

for the sole and exclusive purpose referenced above, and agrees not to use the Evaluation Board for any other purpose. Furthermore, the license granted is expressly made subject to the following additional

limitations: Customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the Evaluation Board; and (ii) permit any Third Party to access the Evaluation Board. As used herein, the term

“Third Party” includes any entity other than ADI, Customer, their employees, affiliates and in-house consultants. The Evaluation Board is NOT sold to Customer; all rights not expressly granted herein, including

ownership of the Evaluation Board, are reserved by ADI. CONFIDENTIALITY. This Agreement and the Evaluation Board shall all be considered the confidential and proprietary information of ADI. Customer may

not disclose or transfer any portion of the Evaluation Board to any other party for any reason. Upon discontinuation of use of the Evaluation Board or termination of this Agreement, Customer agrees to

promptly return the Evaluation Board to ADI. ADDITIONAL RESTRICTIONS. Customer may not disassemble, decompile or reverse engineer chips on the Evaluation Board. Customer shall inform ADI of any

occurred damages or any modifications or alterations it makes to the Evaluation Board, including but not limited to soldering or any other activity that affects the material content of the Evaluation Board.

Modifications to the Evaluation Board must comply with applicable law, including but not limited to the RoHS Directive. TERMINATION. ADI may terminate this Agreement at any time upon giving written notice

to Customer. Customer agrees to return to ADI the Evaluation Board at that time. LIMITATION OF LIABILITY. THE EVALUATION BOARD PROVIDED HEREUNDER IS PROVIDED “AS IS” AND ADI MAKES NO

WARRANTIES OR REPRESENTATIONS OF ANY KIND WITH RESPECT TO IT. ADI SPECIFICALLY DISCLAIMS ANY REPRESENTATIONS, ENDORSEMENTS, GUARANTEES, OR WARRANTIES, EXPRESS OR IMPLIED, RELATED

TO THE EVALUATION BOARD INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, TITLE, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF INTELLECTUAL

PROPERTY RIGHTS. IN NO EVENT WILL ADI AND ITS LICENSORS BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES RESULTING FROM CUSTOMER’S POSSESSION OR USE OF

THE EVALUATION BOARD, INCLUDING BUT NOT LIMITED TO LOST PROFITS, DELAY COSTS, LABOR COSTS OR LOSS OF GOODWILL. ADI’S TOTAL LIABILITY FROM ANY AND ALL CAUSES SHALL BE LIMITED TO THE

AMOUNT OF ONE HUNDRED US DOLLARS ($100.00). EXPORT. Customer agrees that it will not directly or indirectly export the Evaluation Board to another country, and that it will comply with all applicable

United States federal laws and regulations relating to exports. GOVERNING LAW. This Agreement shall be governed by and const

rued in accordance with the substantive laws of the Commonwealth of

Massachusetts (excluding conflict of law rules). Any legal action regarding this Agreement will be heard in the state or federal courts having jurisdiction in Suffolk County, Massachusetts, and Customer hereby

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UG09753-0-6/12(C)

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