Analog Devices EVAL-AD7276SDZ User manual

Evaluation Board User Guide
UG-xxx-AD7276
One Technology Way •P. O. Box 9106 •Norwood, MA 02062-9106, U.S.A. •Tel: [phone] •Fax: [phone] •www.analog.com
Evaluating the AD7276
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.Rev. PrA | Page 1 of 28
Full-featured evaluation board for the AD7276
PC control in conjunction with the System Demonstration
Platform (EVAL-SDP-CB1Z)
PC software for control and data analysis (time and
frequency domain)
Standalone capability
EVAL-AD7276SDZ KIT CONTENTS
EVAL-AD7276SDZ Evaluation Board
Evaluation Software CD for the AD7276
9V Mains power supply adapter
ADDITIONAL EQUIPMENT NEEDED
System Demonstration platform (EVAL-SDP-CB1Z)
Precision Analog signal source
SMB cables
USB Cables
EVALUATION BOARD DESCRIPTION
The E VA L -AD7276SDZ is a full-featured evaluation board,
designed to allow the user to easily evaluate all features of the
AD7276. The evaluation board can be controlled via the system
demonstration platform (SDP) connector (J8). The EVAL-SDP-
CB1Z board allows the evaluation board to be controlled via the
USB port of a PC using the AD7276 evaluation software.
The E VA L -AD7276SDZ generates all required power supplies
on board and supplies power to the EVAL-SDP-CB1Z controller
board.
On-board components include the:
•AD8022: Dual High Speed, Low Noise Op Amp
•ADA4000-1: Single, Low Cost, Precision JFET Input
Operational Amplifier
•AD780: 2.5 V/3.0 V Ultrahigh Precision Bandgap
Voltage Reference
•ADP1613: Step-Up PWM DC-to-DC Switching
Converter,
•ADP1720: 50 mA, High Voltage, Micropower Linear
Regulator
•ADP7104: 20 V, 500 mA, Low Noise, CMOS LDO
ADM1185: Quad Voltage Monitor and Sequencer
•ADG3308: Low Voltage, 1.15 V to 5.5 V, 8-Channel
Bidirectional Logic Level Translator
Various link options are described in the Evaluation Board
Hardware section.

Evaluation Board User Guide
UG-xxx-AD7276
One Technology Way •P. O. Box 9106 •Norwood, MA 02062-9106, U.S.A. •Tel: [phone] •Fax: [phone] •www.analog.com
Evaluating the AD7276
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.Rev. PrA | Page 2 of 28
FUNCTIONAL BLOCK DIAGRAM
CS
AD7276
EVAL-SDP-CB1Z
CONTROLLER
BOARD
5 V
BF527
DSP
SERIAL
INTERFACE
ON-BOARD
POWER SUPPLIES
VAMP-
ADG3308
LEVEL
SHIFTER
VIN
DC
INPUT
JACK
VAMP+
GND
SCLK
VIN
+
-
AD780
Ref
VDD
GND
GND
EVAL-AD7276SDZ
ADP7104
SDP 5V
ADP1613
+/-5V
ADP1720
3.3V
AM1185
POWER
SEQUENCER
OP AMP
SUPPLIES
ADA4000-1
VIN
VDD
7-9V
SDATA
GND
BIAS UP
CIRCUIT
VIN Unbiased
VIN
AD8022
BUFFER
48MHZ
SCLK
ADA4000-1
BUFFER
Figure 1 Functional Block Diagram

Evaluation Board User Guide UG-xxx-AD7276
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TABLE OF CONTENTS
E VA L-AD7276SDZ KIT Contents..............................................1
Additional Equipment Needed........................................................1
Evaluation Board Description .........................................................1
Functional Block Diagram ...............................................................2
Revision History ................................................................................3
E VA L-AD7276SDZ Quickstart Guide ...........................................4
Recommended Quick Start GUIDE...........................................4
Evaluation Board Hardware.............................................................5
AD7276 Device description.........................................................5
Hardware Link Options................................................................6
Power Supplies...............................................................................8
Serial Interface...............................................................................8
Stand-alone mode .........................................................................8
Analog Inputs ................................................................................8
Reference Options.........................................................................9
Sockets/Connectors ......................................................................9
E VA L-AD7276SDZ Basic Hardware Setup ..........................10
Evaluation Board SoftwarE............................................................11
Software Installation...................................................................11
Launching The Software ............................................................13
Software Operation.....................................................................13
Description of User Software panel..........................................14
WaveForm Capture .....................................................................16
AC Testing - Histogram .............................................................17
DC Testing - Histogram.............................................................17
AC Testing - FFT Capture..........................................................18
Summary Tab...............................................................................19
Save File ........................................................................................20
Load File.......................................................................................20
Evaluation Board Schematics and Artwork.................................21
REVISION HISTORY
07/12—Revision PrA

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EVAL-AD7276SDZ QUICKSTART GUIDE
RECOMMENDED QUICK START GUIDE
To install the software do the following:
(1) Install the AD7276 Software from the enclosed CD.
Ensure the EVAL-SDP-CB1Z board is disconnected
from the USB port of the PC while installing the
software. The PC must be restarted after the
installation.
(2) Connect the EVAL-SDP-CB1Z board to the E VA L-
AD7276SDZ board as shown in
(3) Figure 2.
(4) Screwing the two boards together with the enclosed
nylon screw-nut set will ensure the boards connect
firmly together.
(5) Connect the 9V power supply adapter included in the
kit to connecter J702 on the EVAL-AD7276SDZ
board.
(6) Connect the EVAL-SDP-CB1Z board to the PC via the
USB cable. For Windows XP you may need to search
for the EVAL-SDP-CB1Z drivers. Choose to
automatically search for the drivers for the EVAL-
SDP-CB1Z board if prompted by the operating
system.
(7) Launch the E VA L -AD7276SDZ software from the
Analog Devices subfolder in the Programs menu.
Figure 2. Hardware Configuration – Setting up the EVAL-AD7276SDZ.

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EVALUATION BOARD HARDWARE
AD7276 DEVICE DESCRIPTION
The AD7276/AD7277/AD7278 are 12-/10-/8-bit, high speed,
low power, successive approximation analog-to-digital
converters (ADCs), respectively. The parts operate from a single
2.35 V to 3.6 V power supply and feature throughput rates of up
to 3 MSPS. The parts contain a low noise, wide bandwidth
track-and-hold amplifier that can handle input frequencies in
excess of 55 MHz.
The conversion process and data acquisition are controlled
using CS and the serial clock, allowing the devices to interface
with microprocessors or DSPs. The input signal is sampled on
the falling edge of CS, and the conversion is also initiated at this
point. There are no pipeline delays associated with the part.
The AD7276/AD7277/AD7278 use advanced design techniques
to achieve very low power dissipation at high throughput rates.
The reference for the part is taken internally from VDD. This
allows the widest dynamic input range to the ADC; therefore,
the analog input range for the part is 0 to VDD. The conversion
rate is determined by the SCLK.

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HARDWARE LINK OPTIONS
There are 12 link options, which must be set for the required operating setup before using the evaluation board. The functions of these
options are outlined in Table 1. Shows the position in which all the links are set when the evaluation board is packaged. Jumper and
solder link (LKx) options must be set correctly to select the appropriate operating setup before using the evaluation board. The default
link positions are shown in Table 2 and the functions of these options are outlined in Table 1
Table 1 Link Options
Link No. Function
LK1
-AMP: Amplifier negative voltage supply Selection
PositionA: Amplifier negative voltage supplied from on board supply
Position B: Amplifier negative voltage supplied from external source via J3 terminal 1.
LK2
+AMP: Amplifier Positive voltage Selection
Position A: Amplifier Positive voltage supplied from on board supply
Position B: Amplifier Positive voltage supplied from external source via J3 terminal 3.
LK3
Bias Up voltage select: Selects voltage level supplied to U4
Position A:Selected voltage level is VDD
Position B: Selected voltage level is 0V
LK4
VDD source select
Position A:VDD is sourced from U5
Position B: VDD is sourced externally via J4
LK5
U5 output voltage select:
PLACED: U5 output voltage is 3.0V
REMOVED: U5 output voltage is 2.5V
LK6 VIN Unbiased input impedance selection.
INSERTED: input impedance is 51Ω
LK7
CS signal
Position A: connected from EVAL-SDP-CB1Z
Position B: connected externally via J6
LK8 Biased signal Input
INSERTED: Biased up signal is available to the input buffer U7-A
LK9 SCLK signal
Position A: connected from EVAL-SDP-CB1Z
Position B: connected externally via J8
LK10 Buffer Input Source
PositionA: Input signal applied to Buffer U7-A
Position B: Input to Buffer U7-A set to 0V
LK11 VIN input impedance selection.
INSERTED: input impedance is 51Ω
LK12 SDATA signal
Position A: connected to EVAL-SDP-CB1Z
Position B: connected externally via J9
1 Both LK1 and LK2 should always be in matching positions.

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Table 2 Link Options -Setup condition
Link No. Position Function
LK1 A Amplifier negative voltage supplied from on board supply
LK2 A Amplifier Positive voltage supplied from on board supply
LK3 A Selected voltage level is VDD to U4-A
LK4 A VDD sourced from U5
LK5
INSERTED
U5 output voltage is 3.0V
LK6 INSERTED VIN Unbiased input impedance is 51Ω
LK7 A Connected to EVAL-SDP-CB1Z
LK8 INSERTED Biased up signal is available to the input buffer U7-A
LK9 A Connected to EVAL-SDP-CB1Z
LK10 A Input signal applied to Buffer U7-A
LK11 INSERTED VIN Unbiased input impedance is 51Ω
LK12 A Connected to EVAL-SDP-CB1Z

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POWER SUPPLIES
Care should be taken before applying power and signals to the
evaluation board to ensure that all link positions are as required
by the operating mode.
When using the E VA L-AD7276SDZ in conjunction with the
EVAL-SDP-CB1Z board, connect the AC transformer to
connector J1. VDD,+AMP and -AMP are generated on-board.
Alternatively a bench power supply may be connected to J2 to
supply 7V to 9V
Table 3. External Power Supply Requirements
POWER
SUPPLY
VOLTAGE
RANGE
PURPOSE
VIN1
J1
J2
7V to 9V Supplies all onboard power supplies
which generate all required voltages
to run the evaluation board
AMP+
J3-3
+5V Amplifier positive supply
AMP-
J3-1
-5V Amplifier negative supply
VDD
J4
2.35V to
3.6V
VDD digital supply.
1. When this is supplied all other power supplies are available onboard.
If this supply is not used then all other supplies must be sourced from
an external source.
SERIAL INTERFACE
The AD7276 uses a high speed serial interface which allows
sampling rates up to 3MSPS. For details on the operation of the
serial bus, refer to the AD7276 datasheet.
The E VA L -AD7276SDZ communicates with the EVAL-SDP-
CB1Z board using level shifters. The EVAL-SDP-CB1Z
operates at a 3.3V logic level. This allows VDRIVE voltages to
exceed 3.3V to be used without damaging the SDP interface.
Details of the serial interface can be found in the AD7276
Datasheets.
STAND-ALONE MODE
The E VA L -AD7276SDZ may also be used without the EVAL-
SDP-CB1Z. In this case, connection to the digital interface in
made via the SMB footprints as follows:
Table 4. Standalone Jumper Settings
PIN SMB JUMPER SETTINGS
CS J6 Shorting link in position B
SCLK J8 Shorting link in position B
SDATA J9 Shorting link in position B
ANALOG INPUTS
Two options are available:
VIN (J7)
Use this input when a unipolar signal source is available. The
input is buffered by U7 and fed to the AD7276 via an R-C filter.
Table 5. Unipolar Input Jumper Settings
LINK JUMPER SETTINGS
LK8 Removed
All other link as Table 2 Link Options -Setup condition
VIN UNBIASED (J5)
Use this when the signal source is bipolar. The input is biased
up by U6 and buffered by U7 and fed to the AD7276 via an R-C
filter.
Table 6. Bipolar Input Jumper Settings
LINK JUMPER SETTINGS
LK11 Removed
All other link as Table 2 Link Options -Setup condition

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REFERENCE OPTIONS
the reference source is an AD780: 2.5 V/3.0 V Ultrahigh
Precision Bandgap Voltage Reference. The reference is taken from
the VDD pin of the AD7276. An external VDD voltage may also
be applied to J4
SOCKETS/CONNECTORS
Table 7 Socket connector functions
Socket Function
J1 PWR 7- 9V DC transformer power connector.
J2 7-9V bench supply screw terminal connector.
J3
VSS & VDD
Screw terminal connectors for external
amplifier power supplies.
J4 External power supply for VDD of the AD7276.
J5
VIN UNBIASED
Analog input for use with bipolar signal
sources.
J6
CS
External connection to CS .
J7
VIN UNBIASED
Analog input for use with unipolar signal
sources.
J8
SCLK
External connection to SCLK.
J9
SDATA
External connection to SDATA.
J10 EVAL-SDP-CB1Z Eval board controller socket

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EVAL-AD7276SDZ BASIC HARDWARE SETUP
The AD7276 evaluation board connects to the (EVAL-SDP-
CB1Z) System Demonstration Board. The EVAL-SDP-CB1Z
Board is the controller board, which is the communication link
between the PC and the main evaluation board.
Figure 2 shows a photograph of the connections made between
the AD7276 daughter board and the EVAL-SDP-CB1Z board.
Before connecting power, connect the E VA L -AD7276SDZ
board to connector A or connector B on the EVAL-SDP-CB1Z
board. Nylon screws are included in the E VA L -AD7276SDZ
evaluation kit and can be used to ensure the EVA L -AD7276SDZ
board and the EVAL-SDP-CB1Z board are connected firmly
together.
Once the E VA L-AD7276SDZ board and the EVAL-SDP-CB1Z
board are connected securely, connect the power supplies on
the E VA L -AD7276SDZ board. The E VA L -AD7276SDZ requires
an external power supply which is included in the evaluation
board kit. Connect this power supply to the connector J1 on the
E VA L-AD7276SDZ board. Alternatively, a bench power supply
may be used to power the E VA L -AD7276SDZ via J2. Further
details on the required power supplies connections and options
are detailed in Table 7 Socket connector functions
Before connecting the EVAL-SDP-CB1Z board to your
PC, ensure that the AD7276 software has been installed
from the enclosed CD. The full software installation
procedure is detailed in the Software Installation section.
Finally connect the EVAL-SDP-CB1Z board to the PC via the
USB cable enclosed in the EVAL-SDPCB1Z kit. If using
Windows XP platform, you may need to search for the EVAL
SDP-CB1Z drivers.
Choose to automatically search for the drivers for the EVAL-
SDP-CB1Z board if prompted by the operating system.

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EVALUATION BOARD SOFTWARE
SOFTWARE INSTALLATION
The EVAL-AD7276SDZ evaluation kit includes software on
a CD. Click the setup.exe file from the CD to run the install.
The default location for the software is
C:\Program Files\Analog Devices\E VA L-AD7276_77_78SDZ
Note:
Install the evaluation software before connecting the
evaluation board and E VA L -SDP-CB1Z board to the USB
port of the PC to ensure that the evaluation system is correctly
recognized when connected to the PC.
There are two parts to the install:
1. AD7276 Evaluation board software Install.
2. E VA L-SDP-CB1Z System Demonstration Platform
Board Drivers install
Figure 3 to Figure 7 show the separate stages of the AD7276
evaluation software. Figure 8 to Figure 12 show the separate
steps to install the EVAL-SDP-CB1Z drivers. Proceed through
all of the installation steps allowing the software and drivers to
be placed in the appropriate locations. Only after the software
and drivers have been installed should you connect the EVAL-
SDP-CB1Z board to the PC.
Figure 3. AD7276 Install Window 1
Figure 4 AD7276.Install Window 2
Figure 5 Install Window 3
Figure 6. AD7276 Install Window 4

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Figure 7. AD7276 Install Window 5.
Figure 8. ADI EVAL-SDP-CB1Z Drivers Setup Window 1.
Figure 9. ADI EVAL-SDP-CB1Z Drivers Setup Window 2.
Figure 10. ADI EVAL-SDP-CB1Z Drivers Setup Window 3
Figure 11. ADI EVAL-SDP-CB1Z Drivers Setup Window 4
Figure 12. ADI EVAL-SDP-CB1Z Drivers Setup Window 5

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After installation from CD is complete, connect the E VA L -
AD7276SDZ to the EVAL-SDP-CB1Z as described in the
Evaluation Board Hardware section.
When you first plug in the E VA L-SDP-CB1Z board via the USB
cable provided, allow the new Found Hardware Wizard to run.
Once the drivers are installed, you may check that the board
has connected correctly by looking at the Device Manager of
the PC. The Device Manager can be found by right clicking on
My Computer->Manage ->Device Manager from the list of
System Tools as shown below. The E VA L -SDP-CB1Z Board
should appear under ADI Development Tools. This completes
the installation.
Figure 13. Device Manager
LAUNCHING THE SOFTWARE
Once the E VA L-AD7276SDZ a n d E VA L -SDP-CB1Z are
correctly connected to your PC, the AD7276 software can be
launched.
To launch the software, complete the following steps:
1. From the Start menu, select Programs ->Analog Devices -
> E VA L -AD7276_77_78SDZ > AD7276.The main
window of the software then displays.
2. If the AD7276 evaluation system is not connected to the
USB port via the EVAL-SDP-CB1Z when the software is
launched, a connectivity error displays (see Figure 14).
Connect the evaluation board to the USB port of the PC,
wait a few seconds, click Rescan, and follow the
instructions.
09726-002
Figure 14. Connectivity Error Alert
SOFTWARE OPERATION
When the software is launched, the panel will open and the
software will look for hardware connected to the PC. The
software will detect the generic attached to the PC and return
this in a user dialog box.
The user software panel will then launch as shown in Figure 15.

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Figure 15. Setup Screen
DESCRIPTION OF USER SOFTWARE PANEL
The user software panel as shown in Figure 15 has the following
features:
1. File menu with choice of;
a. Load data: load previously captured data in tsv (tab
separated values) format for analysis
b. Save Data as .tsv: Save captured data in tsv (tab separated
values) format for future analysis
c. Print Front Panel Picture. Use to print the front panel to
your default printer.
d. Save Picture: Use to save the current screen capture
e. Exit
2. Use this drop down menu to select the generic AD7276,
AD7277 or AD7278.
3. Resolution of selected part is displayed
4. Sampling Rate. The default sampling frequency will match
the max sample rate of the ADC selected from the drop
down menu. User can adjust the sampling frequency,
however there are limitations around the sample frequency
where unusable sample frequencies are input, the software
will automatically adjust the sample frequency accordingly.
Units can be entered such as 10k for 10,000Hz etc. As the
max sample frequency possible is device dependent, with
some of the ADCs capable of operating up to 250ksps,
while others can run to 1.3MSPS, the software will match
the particular ADC ability. If the user enters a value larger

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than the ability of the existing device, the software will
indicate this and revert to the max Sample frequency.
5. Exit Button. Use this to exit the software. Alternatively, go
to File->Exit
6. BUSY: This LED indicates when a read is in progress from
the EVAL-SDP-CB1Z board.
7. There are four tabs available displaying the data in different
formats, this are listed here and described in more detail
later.
a. Waveform tab
b. Histogram
c. FFT
d. Summary
8. Select the number of samples to analyze.
9. “Sample” : to perform a single capture.
10. “Continous” : to perform a continuous capture from the
ADC. Press a second time to stop sampling
Within any of the Chart panels, the following tools allow user
control of the different chart displays.
Is used for controlling the cursor if present
Is used for zooming in and out.
Is used for panning.

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Figure 16. Waveform Capture Tab
WAVEFORM CAPTURE
Figure 16 illustrates the waveform capture tab. The input signal
here is a 50kHz sine-wave.
The waveform analysis reports back the amplitudes recorded
from the captured signal in addition to the frequency of the
signal tone.

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Figure 17. Histogram Capture Tab
AC TESTING - HISTOGRAM
Figure 17 shows the histogram capture tab. This tests the ADC
for the code distribution for AC input and computes the mean
and standard deviation, or transition noise of the converter and
displays the results.
Raw data is captured and passed to the PC for statistical
computations. To perform a histogram test, select “Histogram”
tab from the test selection window and click on the “Start”
button.
Note: an AC histogram needs a quality signal source applied to
the input SK1/SK3 connectors. Figure 17 shows the histogram
for a 50kHz sinewave applied to the ADC input and the results
calculated.
1. Illustrates the different measured values for the data
captured.
DC TESTING - HISTOGRAM
More commonly, the histogram would be used for DC testing.
Where user tests the ADC for the code distribution for DC
input and computes the mean and standard deviation, or
transition noise of the converter and displays the results. Raw
data is captured and passed to the PC for statistical
computations. To perform a histogram test, select “Histogram”
tab from the test selection window and click on the “Start”
button.

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Figure 18. FFT Capture Tab
AC TESTING - FFT CAPTURE
Figure 18 shows the FFT capture tab This tests the traditional
AC characteristics of the converter and displays a Fast Fourier
Transform (FFT) of the results. As in the histogram test, raw
data is captured and passed to the PC where the FFT is
performed displaying SNR, SINAD, THD and SFDR. To
perform an AC test, apply a sinusoidal signal to the evaluation
board at the SMB inputs J4/63. Low distortion, better than
115dB, is required to allow true evaluation of the part. One
possibility is to filter the input signal from the AC source. There
is no suggested band-pass filter but consideration should be
taken in the choice. Furthermore, if using a low frequency
band-pass filter when the full-scale input range is more than a
few Vpp, it is recommended to use the on board amplifiers to
amplify the signal, thus preventing the filter from distorting the
input signal.
Figure 18 displays the results of the captured data.
1. Shows the input signal information
2. Displays the fundamental frequency and amplitude in
addition to the 2nd to 5th harmonics.
3. Displays the performance data. SNR, Dynamic Range,
THD, SINAD, Noise performance.

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Figure 19. Summary Tab
SUMMARY TAB
Figure 19 shows the summary tab The summary tab captures all
the display information and provides them in one panel with a
synopsis of the information including key performance
parameters such as SNR and THD

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SAVE FILE
See Figure 20 The software can save the current captured data
for later analysis; the file format is .tsv (tab-separated values).
User will be prompted with a Save dialog box and should save
to an appropriate folder location
LOAD FILE
See Figure 21 User is prompted with a load dialog box. User
may have to navigate to find these files. The default location for
the example files is C:\Program Files\Analog Devices\ E VA L-
AD7276_77_78SDZ
Figure 20 Save File dialog Box
Figure 21 Load File Dialog Box