Evaluation Board for the 8-Channel,
10-/12-Bit ADC with I
2
C-Compatible Interface
EVAL-AD7997EBZ/AD7998EBZ
FEATURES
Full-featured evaluation board for the AD7997/AD7998
PC software for control and measurement of the
AD7997/AD7998
USB interface (cable provided)
Various linking options
The AD7997/AD7998 contain an 8-channel multiplexer and
track-and-hold amplifier that can handle input frequencies of up
to 11 MHz.
Full details on these devices are provided in the AD7997/
AD7998 data sheet available from Analog Devices, Inc., which
should be consulted in conjunction with this data sheet.
On-board components for the EVAL-AD7997/AD7998 include
two
AD5245
digital potentiometers, eight
AD8691
operational
amplifiers, one
AD780
(a pin programmable 2.5 V or 3 V ultra-
high precision band gap reference), and one TMP37 precision
temperature sensor.
The available link options are described in Table 2 and Table 3.
GENERAL DESCRIPTION
This data sheet describes the evaluation board for testing the
AD7997/AD7998
devices. These devices are 10-/12-bit, low
power, successive approximation analog-to-digital converters
(ADCs) with an I
2
C-compatible interface. The parts operate
from a single 2.7 V to 5.5 V power supply and features a 2 μs
conver-sion time.
FUNCTIONAL BLOCK DIAGRAM
AN3
POT2
TMP37
AN0
POT1
AN1
POT2
AN2
POT1
AN4
POT1
AN5
POT2
AN6
POT1
AN7
POT2
V
IN
4
V
IN
1
V
IN
2
SDA
V
IN
3
V
IN
5
SCL
V
IN
6
V
IN
7
V
IN
8
AD7997/AD7998
AD780
J1
USB
CYPRESS
USB
SDA
SCL
REF
IN
J3
J2
EVAL-AD7997EBZ/AD7998EBZ
Figure 1.
Rev. 0
Evaluation boards are only intended for device evaluation and not for production purposes.
Evaluation boards are 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.
www.analog.com
Tel: 781.329.4700
Fax: 781.461.3113
©2008 Analog Devices, Inc. All rights reserved.
06264-001
EVAL-AD7997EBZ/AD7998EBZ
TABLE OF CONTENTS
Features .............................................................................................. 1
General Description ......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Evaluation Board Hardware ............................................................ 3
Initial Setup Conditions .............................................................. 3
Power Supplies .............................................................................. 3
USB Connector ............................................................................. 3
Sockets ........................................................................................... 3
Links ............................................................................................... 4
Evaluation Board Software ...............................................................6
Installing the Software ..................................................................6
Using the Software ........................................................................6
Main Window ................................................................................7
Evaluation Board Schematics and Artwork ...................................8
Ordering Information .................................................................... 12
Bill of Materials ........................................................................... 12
Ordering Guide .......................................................................... 12
ESD Caution................................................................................ 12
REVISION HISTORY
11/08—Revision 0: Initial Version
Rev. 0 | Page 2 of 12
EVAL-AD7997EBZ/AD7998EBZ
EVALUATION BOARD HARDWARE
INITIAL SETUP CONDITIONS
Care should be taken before applying power and signals to the
evaluation board to ensure that all link positions are set as
required by the operating mode.
Because the USB connector powers the board, there is no need
for an external power supply.
Communication between the AD7997/AD7998 evaluation
boards and the PC is over the USB interface. The on-board USB
controller controls this communication.
POWER SUPPLIES
The EVAL-AD7997EBZ/AD7998EBZ are powered via the 5 V
supply from the USB connector, J1. The 5 V supply can be used
to power the
AD7997/AD7998
directly through the EMC_FILTER.
A regulated voltage from the on-board
ADP3303,
a high pre-
cision, low power, 3.3 V output voltage regulator, can also be
used. To select the power supply for the AD7997/AD7998, choose
LK7 (see the Links section).
SOCKETS
There are 10 input sockets (AN0 through AN7, J2, and J3)
relevant to the operation of the AD7997/AD7998 on these
evaluation boards. The functions of these sockets are outlined
in Table 1.
USB CONNECTOR
A standard USB connector, J1, is used to connect the evaluation
board to the USB port of a PC. A standard USB connector cable
is included with the AD7997/AD7998 evaluation board kits.
Table 1. Socket Functions
Socket
AN0 to AN7
J2
J3
Function
Subminiature BNC (SMB) Connector. The analog input signal for V
IN
1 through V
IN
8 of the AD7997/AD7998 is
applied to these sockets.
Subminiature BNC (SMB) Connector. This socket is connected to the SDA track on the evaluation board.
Subminiature BNC (SMB) Connector. This socket is connected to the SCL track on the evaluation board.
Rev. 0 | Page 3 of 12
EVAL-AD7997EBZ/AD7998EBZ
LINKS
Link options can be set to change the configuration of the
circuits. Table 2 shows the positions in which all the links are
set when the evaluation boards are shipped.
The functions of these link options are summarized in Table 3.
The positions of the links can be changed when the evaluation
board is connected to the power supply.
Table 2. Initial Link Positions
Link No.
LK1
LK2
LK3
LK4
LK5
LK6
LK7
LK8
LK9
LK10
LK11
LK12
LK13
LK14
LK15
LK16
LK17
LK18
LK19
LK20
LK21
LK22
LK23
LK24
LK25
LK26
LK27
Position
A
A
A
A
A
A
A
Insert
B
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
Function
V
IN
1 is connected to digital Potentiometer 1.
Operational amplifier is supplied from J1 (Channel 1).
Operational amplifier is used on Channel 1.
V
IN
2 is connected to digital Potentiometer 2.
Operational amplifier is supplied from J1 (Channel 2).
Operational amplifier is used on Channel 2.
Power source of AD7997/AD7998 is set to 5 V (J1 connector).
External reference voltage has a value of 3 V.
Reference input of AD7997/AD7998 is connected to 5 V.
Operational amplifier is used on Channel 3.
Operational amplifier is supplied from J1 (Channel 3).
V
IN
3 is connected to digital Potentiometer 1.
Operational amplifier is used on Channel 4.
Operational amplifier is supplied from J1 (Channel 4).
V
IN
4 is connected to digital Potentiometer 2.
Operational amplifier is used on Channel 5.
Operational amplifier is supplied from J1 (Channel 5).
V
IN
5 is connected to digital Potentiometer 1.
Operational amplifier is used on Channel 6.
Operational amplifier is supplied from J1 (Channel 6).
V
IN
6 is connected to digital Potentiometer 2.
Operational amplifier is used on Channel 7.
Operational amplifier is supplied from J1 (Channel 7).
V
IN
7 is connected to digital Potentiometer 1.
Operational amplifier is used on Channel 8.
Operational amplifier is supplied from J1 (Channel 8).
V
IN
8 is connected to digital Potentiometer 2.
Rev. 0 | Page 4 of 12
EVAL-AD7997EBZ/AD7998EBZ
Table 3. Link Options
Link No.
LK1, LK4, LK12, LK18, LK21,
LK24, LK27
Function
These links connect the input of V
IN
1 through V
IN
8 to the corresponding AN0 through AN7 socket, where
V
IN
1 connects to AN0 and so on. Alternatively, these links connect to an input socket or to a digital
potentiometer.
In Position A, V
IN
X is connected to the digital potentiometer.
In Position B, V
IN
X is connected to the ANx input socket.
These links connect the power supply pins of the operational amplifiers to 3.6 V regulated output from the
on-board ADP3330 voltage regulators, or to 5 V supply from J1.
In Position A, an operational amplifier is supplied from J1.
In Position B, an operational amplifier is supplied from the ADP3330.
These links tie the operational amplifiers to the analog inputs of the AD7997/AD7998.
In Position A, the operational amplifier is used.
In Position B, the operational amplifier is not used.
LK7 selects the power source for V
DD
on the AD7997/AD7998.
In Position A, LK7 selects the 5 V supply from the USB connector.
In Position B, LK7 selects the 3.3 V regulated output from the on-board ADP3303 voltage regulator.
LK8 changes the value of the external reference voltage (AD780).
If this link is inserted, the reference voltage is 3 V.
If this link is not inserted, the reference voltage is 2.5 V.
LK9 changes the source of the reference voltage for the AD7997/AD7998.
In Position A, an external reference source is used (AD780).
In Position B, the 5 V supply from J1 is used as a reference voltage.
LK15 connects the input of V
IN
4 to the AN3 input socket, to a digital potentiometer or to a temperature
sensor.
In Position A, V
IN
4 is connected to digital Potentiometer 2.
In Position B, V
IN
4 is connected to the AN3 input socket.
In Position C, V
IN
4 is connected to the temperature sensor.
LK2, LK5, LK11, LK14, LK17,
LK20, LK23, LK26
LK3, LK6 , K10, LK13, LK16,
LK19, LK22, LK25
LK7
LK8
LK9
LK15
Rev. 0 | Page 5 of 12
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