EVAL-AD7768-4FMCZ User Guide
UG-921
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 Board for the AD7768-4 24-Bit, 4-Channel, Simultaneous Sampling,
256 kSPS, Sigma-Delta ADC with Power Scaling
FEATURES
GENERAL DESCRIPTION
Full featured evaluation board for the AD7768-4
PC control in conjunction with the SDP-H1
system demonstration platform (EVAL-SDP-CH1Z)
PC software control and data analysis
Time and frequency domain
Standalone hardware capability
The EVAL-AD7768-4FMCZ evaluation kit features the
AD7768-4 24-bit, 256 kSPS, analog-to-digital converter (ADC).
A 7 V to 9 V external bench top supply is regulated to 5 V and
3.3 V to supply the AD7768-4 and support components. The
EVAL-AD7768-4FMCZ board connects to the USB port of the PC
via a connection to the SDP-H1 motherboard, EVAL-SDP-CH1Z.
ONLINE RESOURCES
The AD7768-4 evaluation software fully configures the AD7768-4
device register functionality and provides dc and ac time domain
analysis in the form of waveform graphs, histograms, and
associated noise analysis for ADC performance evaluation.
Evaluation Kit Contents
EVAL-AD7768-4FMCZ evaluation board
Evaluation software CD for the AD7768-4
Documents Needed
AD7768-4 data sheet
EVAL-AD7768-4FMCZ user guide
Required Software
AD7768-4 evaluation software
EQUIPMENT NEEDED
EVAL-AD7768-4FMCZ evaluation board
EVAL-SDP-CH1Z system demonstration platform
External 7 V to 9 V bench top power supply
DC/AC signal source (Audio Precision® or similar high
performance signal source)
USB cable
PC running Windows with USB 2.0 port
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.
The EVAL-AD7768-4FMCZ is an evaluation board that allows the
user to evaluate the features of the ADC. The user PC software
executable controls the AD7768-4 over a USB cable through the
EVAL-SDP-CH1Z system demonstration platform (SDP).
Full specifications on the AD7768-4 are available in the product
data sheet, which should be consulted in conjunction with this
user guide when working with the evaluation board.
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EVAL-AD7768-4FMCZ User Guide
TABLE OF CONTENTS
Features .............................................................................................. 1
Power Supplies ...............................................................................8
Online Resources .............................................................................. 1
Serial Data Interface ......................................................................8
Equipment Needed ........................................................................... 1
Serial Configuration Interface .....................................................8
General Description ......................................................................... 1
Powering Down the System Demonstration Platform ...............8
Revision History ............................................................................... 2
Sockets/Connectors ......................................................................9
EVAL-AD7768-4FMCZ Quick Start Guide .................................. 3
Evaluation Board Setup Procedures ...........................................9
Analog Inputs and Front-End Circuit ........................................... 4
Evaluation Board Software ............................................................ 10
Evaluation Board Hardware ............................................................ 5
Software Installation Procedures.............................................. 10
Device Description ....................................................................... 5
Setting Up the System for Data Capture ................................. 13
Hardware Link Options ............................................................... 5
Software Operation .................................................................... 14
REVISION HISTORY
3/16—Revision 0: Initial Version
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EVAL-AD7768-4FMCZ QUICK START GUIDE
To begin using the EVAL-AD7768-4FMCZ evaluation board,
take the following steps:
2.
Ensure that the EVAL-SDP-CH1Z SDP-H1 board is
disconnected from the USB port of the PC. Install the
evaluation board software from the CD included in the
evaluation board kit. Restart the PC after the software
installation is complete. (For complete software installation
instructions, see the Software Installation Procedures
section.)
Connect the SDP-H1 board to the evaluation board
(unpowered). Figure 1 illustrates the connection: J4 of the
SDP-H1 board adapts to the receiving socket on the EVALAD7768-4FMCZ printed circuit board (PCB).
APPLY 7V TO 9V
BETWEEN VIN AND GND
ON J3 CONNECTOR
J1 BARREL
CONNECTOR
ADA4896-2
AMPLIFIERS
GAIN = 1
Ensure that the boards are connected firmly together.
Apply power to the evaluation board via the supplied 9 V dc
adapter at J1 (LK1 in Position B). Alternatively, supply an
external voltage in the range of 7 V to 9 V from a bench top
power supply using the J3 connector (LK1 in Position A).
Connect the 12 V dc supply to the SDP-H1 board, and
then connect to the PC using the supplied USB cable. For
Windows® XP, the PC may need to search for the SDP
drivers. Choose to automatically search for the drivers for
the SDP-H1 board if prompted by the operating system.
Launch the AD7768-4 evaluation software from the
Analog Devices subfolder in the Programs menu.
5.
6.
AD7768-4
24-BIT, 4-CHANNEL
SAMPLING ADC
ADR444
4.096V
PRECISION
REFERENCE
CONNECTION TO
SDP BOARD
ANALOG INPUT CONNECTIONS
SMB CONNECTIONS: AC INPUTS (AIN0± TO AIN3±)
TERMINAL BLOCKS: DC INPUTS (J4 AND J5)
Figure 1. EVAL-AD7768-4FMCZ Evaluation Board
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14130-001
1.
3.
4.
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EVAL-AD7768-4FMCZ User Guide
ANALOG INPUTS AND FRONT-END CIRCUIT
As shown in Figure 1, the AIN0± to AIN3± analog inputs are
accessible through either the SMBs or the terminal blocks.
The ADR444 4.096 V low noise reference is used by default,
allowing an absolute input range of 0||4.096 V on each input.
Figure 2 shows these connectors and details the eight main solder
links that route the inputs from either the terminal blocks or the
SMBs for each of the signals.
The ADA4896-2 amplifiers are not terminated at the inputs for
any particular source impedances.
In the default board configuration, the input terminals are
connected through to the ADA4896-2 on each of the ADC
channels.
TERMINAL
BLOCKS
J4, J5
The on-board, common-mode voltage source on the AD7768-4
is used to bias the input signal. The default condition is VCM =
(AVDD1 − AVSS)/2.
SOLDER LINK TYPES TO ROUTE ANALOG INPUTS TO ADC INPUTS
CH2
SOLDER LINKS
SL2+, SL2–, SL1+, SL1–
CHANNEL 2, CHANNEL 1, CHANNEL 0
B
DIRECT TO ADC INPUT
TO ADC INPUT VIA ADA4896-2,
A
G = 1 (DEFAULT)
CLOCK
(32MHz)
4× ADA4896-2
SOLDER LINKS:
SL3 + 1, SL3 – 1
FOR CHANNEL 3 ONLY
A
CH1
J4
CH0
ADC DATA
AD7768-4
SPI CONTROL
TO ADC INPUT VIA ADA4896-2, G = 1
B
DIRECT TO ADC INPUT
ADR444
C
Figure 2. Analog Inputs: Input Connectors, Solder Links, and Amplifiers
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14130-002
CH3
160-PIN CONNECTOR TO EVAL-SDP-CH1Z
J5
EVAL-AD7768-4FMCZ User Guide
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EVALUATION BOARD HARDWARE
DEVICE DESCRIPTION
The AD7768-4 is a 4-channel, simultaneously sampling,
Σ-Δ ADC. The AD7768-4 offers an ADC per channel and
synchronized sampling. The ADC power scaling is as required
for the application, catered for by selecting one of the following
modes of operation:
Fast: 256 kSPS maximum, 110.8 kHz input bandwidth,
59 mW per channel
Median: 128 kSPS maximum, 55.4 kHz input bandwidth,
32 mW per channel
Economy: 32 kSPS maximum, 13.8 kHz input bandwidth,
12.2 mW per channel
The AD7768-4 offers extensive digital filtering:
Wideband: low ripple, antialiasing, low pass filter with
sharp roll off, and full attenuation at Nyquist frequency.
Sinc response: sinc5 filter, low latency path for dc
measurements or control loops.
Within these filter options, the user can select a decimation rate
of 32, 64, 128, 256, 512, or 1024.
Embedded analog functionality on each ADC channel
simplifies system design. A precharge buffer on each analog
input reduces analog input current.
Complete specifications for the AD7768-4 are provided in the
product data sheet and should be consulted in conjunction with
this user guide when using the evaluation board. Full details
about the EVAL-SDP-CH1Z SDP-H1 board are available on the
Analog Devices, Inc., website at www.analog.com.
HARDWARE LINK OPTIONS
The default link options are listed in Table 1. The board can
be configured to operate from a bench top power supply via
Connector J3, or from a 9 V dc adapter via Connector J1. The
supply required for the AD7768-4 comes from the on-board
low dropout regulators (LDOs), which generate their input
voltage from J1 or J3 depending on the setting of LK1.
Alternatively, the board can be powered by setting LK2 to
Position A when used in conjunction with the SDP-H1 board
(see Table 3 for details).
Table 1. Default Link and Solder Link Options
Link No.
LK1
Default Option
A
LK2
B
SL1
A
SL2
B
SL4
A
SL4A
A
SL5
Soldered 0 Ω resistor
SL6
A
Description
LK1 selects the input voltage source.
Position A: J3 is selected.
Position B: J1 is selected.
LK2 selects the input from EVAL-SDP-CH1Z board.
Position A: 12 V input from EVAL-SDP-CH1Z.
Position B: external power supply from either J1 or J3.
SL1 selects between pin or SPI mode operation of the AD7768-4.
Position A: SPI mode.
Position B: pin mode (pin mode is not compatible with the evaluation software and currently
untested on evaluation board).
FORMAT0 pin.
Position A: IOVDD.
Position B: DGND.
Clock terminal source selection. To choose the Y1 crystal oscillator, do not populate SL4. R253, R254,
C46, and C45 must be populated. SL4A must be configured to the crystal oscillator.
Position A: selects CMOS Oscillator Y2.
Position B: unpopulated terminals (J6 and J7).
Position C: SDP MCLK.
Clock select (CLK_SEL) pin.
CMOS clock option on Pin 32.
Crystal oscillator or LVDS option.
Shorts SYNC_OUT to SYNC_IN to allow sync pulses on START to be synchronously applied to SYNC_IN.
Pin 16: ST0/CS.
Position A: CS pin in SPI mode.
Position B: Channel 0 to Channel 3 power down (pin mode).
Position C: Channel 0 to Channel 3 enabled (pin mode).
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EVAL-AD7768-4FMCZ User Guide
Link No.
SL7
Default Option
A
SL8
A
SL9
A
SL10
A
SL11
A
SL12
A
SL13
A
SL14
A
SL15
A
SL16
B
SL17
B
SL18
SL19
Unsoldered
A
SL22, SL23
Description
Pin 17: ST1/SCLK.
Position A: SCLK in SPI mode.
Position B: pin mode.
Pin 18: DEC1/SDI.
Position A: SDI in SPI mode.
Position B: IOVDD.
Position C: GND.
Pin 19: DEC0/SDO.
Position A: SDO in SPI mode.
Position B: IOVDD.
Position C: GND.
Pin 12: MODE0/GPIO0.
Position A: GPIO to SDP.
Position B: GND.
Position C: IOVDD.
Pin 13: MODE1/GPIO1.
Position A: GPIO to SDP.
Position B: GND.
Position C: IOVDD.
Pin 14: MODE2/GPIO2.
Position A: GPIO to SDP.
Position B: GND.
Position C: IOVDD.
Pin 15: MODE3/GPIO3.
Position A: GPIO to SDP.
Position B: GND.
Position C: IOVDD.
Pin configuration mode. AD7768-4 evaluation kit software runs from SPI mode; select the filter via
the register map. This link selects the filter mode (only available in pin mode).
Position A: GPIO4.
Position B: sinc5 fast settling filter.
Position C: wideband low ripple filter.
Select common-mode voltage to bias input signals to one of the following.
Position A: OP2177 buffered VCM output.
Position B: VCM output from AD7768-4.
Select reference path from ADR444 to REFx+.
Position A: bypass external reference buffer.
Position B: ADR444 input into ADA4841-1 reference buffer.
Select reference path from ADR444 to REFx+.
Position A: bypass external reference buffer.
Position B: select output from ADA4841-1 reference buffer.
Shorts IOVDD to DREGCAP, only for IOVDD = 1.8 V operation; see the AD7768-4 data sheet.
External common-mode buffer input selection.
Position A: AD7768-4 VCM pin.
Position B: AVDD1 used for common-mode selection, R166 (0 Ω) and R167 (not inserted) can be used
as voltage dividers.
Selects the output from Channel 3 amplifier driver option.
Position A: ADA4896-2.
Position B: bypass driver.
Position C: amplifier driver board header via the J11 and J12 connectors.
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EVAL-AD7768-4FMCZ User Guide
Link No.
SLP1
Default Option
A
SLP2
A
SLP4
A
SL_AMP+
A
SL_AMP−
A
SL2+ to SL0+,
SL2− to SL0−
A
SL3+, SL3−
A
UG-921
Description
AVDD1 input selector.
Position A: ADP7118ARDZ-5.0 5 V LDO.
Position B: external AVDD1 input (J2, Pin 3).
AVDD2 LDO selector.
Position A: ADP7118ARDZ-5.0 5 V LDO.
Position B: external AVDD2 input (J2, Pin 4).
IOVDD input selector.
Position A: ADP7118ARDZ-3.3 3.3 V LDO.
Position B: external AVDD2 input (J2, Pin 5), 2.25 V to 3.6 V, 1.8 V.
ADA4896-2 positive supply voltage.
Position A: AVDD1 ADP7118ARDZ-5.0 supply.
Position B: external supply to board, J1 or J3 input depending on LK1 position.
ADA4896-2 negative supply voltage.
Position A: evaluation board ground plane.
Position B: external supply to board, J1 or J3 input depending on LK1 position, on-board ADA4896-2
are shorted to ground and VSS pins, replace with capacitors for bipolar amplifier supplies.
Selects the input driver for Channel 2, Channel 1, and Channel 0.
Position A: ADA4896-2.
Position B: bypass driver.
Selects the input driver for Channel 3.
Position A: ADA4896-2.
Position B: bypass driver.
Position C: external amplifier driver board header via the J11 and J12 connectors.
On-Board Connectors
Table 2 provides information about the external connectors on the EVAL-AD7768-4FMCZ.
Table 2. On-Board Connectors
Connector
J1
J2
J3
J4
J5
J6
J7
J11
J12
J13, J14
J15
AI0+ to AI3+
AI0− to AI3−
P1
Function
Wall wart (dc plug) power supply voltage input. Apply 7 V to 9 V and GND (0 V) to this connector to power the evaluation board.
Connector for supplying AVDD1, AVDD2, IOVDD, AVSS, and AGND externally.
Bench top power supply voltage input. Apply 7 V to 9 V and GND (0 V) to this connector to power the evaluation board.
4-pin connector for input to Channel 2 and Channel 3.
4-pin connector for input to Channel 0 and Channel 1.
SMA/SMB connector for XTAL2 (CLKIN/LVDS).
SMA/SMB connector for XTAL1 (LVDS).
Optional external connector for driver daughter board. Channel 3.
Optional external connector for driver daughter board. Channel 3.
8-pin connector for input to Channel 0 to Channel 3.
Unpopulated VCM SMA connector.
Analog input SMA positive terminal for Channel 0 to Channel 3.
Analog input SMA negative terminal for Channel 0 to Channel 3.
Connector on the underside of the EVAL-AD7768-4FMCZ board that mates with the EVAL-SDP-CH1Z controller board.
Rev. 0 | Page 7 of 18
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EVAL-AD7768-4FMCZ User Guide
POWER SUPPLIES
SERIAL CONFIGURATION INTERFACE
The evaluation board requires that an external power supply,
either a bench top supply or a wall wart (dc plug) supply, be
applied to J1 or J3 (see Table 3 for more information). Linear
regulators generate the required power supply levels from the
applied VIN rail. The regulators used are the 5 V ADP7118 (U1
and U7), which supply AVDD1, the on-board amplifiers and
reference, and the 3.3 V ADP7118 (U16), which delivers 3.3 V
to the IOVDD pin of the AD7768-4.
The AD7768-4 is configured by the SDP-H1 board via a 4-wire
SPI interface. SL1 must be shorted to Position A for this mode
to be active.
SERIAL DATA INTERFACE
The AD7768-4 evaluation board outputs conversion results to
the EVAL-SDP-CH1Z SDP-H1 board via the four data output
pins, DOUT0 to DOUT3. The serial data interface also includes
signals such as SCLK, DCLK, and DRDY (all are outputs).
POWERING DOWN THE SYSTEM DEMONSTRATION
PLATFORM
When disconnecting the SDP-H1 evaluation platform and
powering down the system, make sure to first exit the evaluation
software. Then, press the reset button on the SDP-H1 board
before disconnecting the 12 V supply and then the USB. Failure
to follow this procedure can cause damage to the SDP-H1 board.
Table 3. AD7768-4 Power Supply1
Power Supply
(VIN) Source
J1
Voltage Range
7 V to 9 V
J3
7 V to 9 V
EVAL-SDP-CH1Z
12 V
1
Function
Wall wart (dc plug) supply to the evaluation board. Supplies LDOs that create the 5 V and 3.3 V rails.
It also supplies the ADR444 external reference. Ensure that both LK1 and LK2 are set to Position B
when the external power supply is applied to this connector.
Bench top supply to the evaluation board. Supplies LDOs that create 5 V and 3.3 V rails. It also
supplies the ADR444 external reference and on-board amplifiers. Ensure that LK1 is set to Position A
when the external power supply is applied to this connector and LK2 is set to Position B.
If using the EVAL-SDP-CH1Z, power can be taken from this board and supplied to the LDOs. Set LK2
to Position A.
Only a single supply is required.
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EVAL-AD7768-4FMCZ User Guide
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SOCKETS/CONNECTORS
Table 4. Connector Details
Connector
J1
J6
Function
Wall wart (dc plug) power supply voltage
input. Apply 7 V.
Apply voltage within data sheet specified
ranges and GND (0 V) to this connector to
power the evaluation board. J2 is the
connector for supplying AVDD1, AVDD2,
IOVDD, AVSS, and AGND externally.
Bench top power supply voltage input. Apply
7 V to 9 V and GND (0 V) to this connector to
power the evaluation board.
SMA/SMB connector for XTAL2 (CLKIN/LVDS).
J7
SMA/SMB connector for XTAL1 (LVDS).
J4
4-pin connector for input to Channel 2 to
Channel 3.
4-pin connector for input to Channel 0 to
Channel 1.
Optional external connector for additional
driver board, Channel 3.
Optional external connector for additional
driver board, Channel 3.
Unpopulated VCM SMA connector.
J2
J3
J5
J11
J12
J15
AI0+ to
AI3+
AI0− to
AI3−
P1
Analog input SMA positive terminal for
Channel 0 to Channel 3.
Analog input SMA negative terminal for
Channel 0 to Channel 3.
Connection to EVAL-SDP-CH1Z controller
board.
Connector Type
2 mm, dc power
connector
5-pin socket terminal
block
Manufacturer/Part No.
Kycon KLDX-SMT2-0202-A
3-pin socket terminal
block, 3.81 mm pitch
Phoenix Contact MC
1,5/3-G-3,81
Farnell 3704737
Straight PCB mount
SMB/SMA jack
Straight PCB mount
SMB/SMA jack
4-pin socket terminal
block, 3.81 mm pitch
4-pin socket terminal
block, 3.81 mm pitch
7-way, 2.54 mm,
vertical socket
7-way, 2.54 mm,
through hole header
Straight PCB mount
SMB/SMA jack
Straight PCB mount
SMB/SMA jack
Straight PCB mount
SMB/SMA jack
160-pin, 10 mm, male,
VITA 57 connector
Tyco 1-1337482-0
Not inserted
Tyco 1-1337482-0
Not inserted
Multicomp, MC000130
Farnell 2008110
Multicomp, MC000130
Farnell 2008110
Samtec SSW-107-01-T-S
Farnell 1803478
Samtec TLW-107-05-G-S
Farnell 1668499
Tyco 1-1337482-0
Farnell 3704737
Tyco 1-1337482-0
Farnell 1206013
Tyco 1-1337482-0
Farnell 1206013
Samtec ASP-134604-01
Farnell 2433507
Lumberg FRE 05
Order No.
Mouser 806-KLDXSMT20202A
Farnell 1217310
EVALUATION BOARD SETUP PROCEDURES
Configuring the Evaluation and SDP Boards
After following the instructions in the Software Installation
Procedures section, set up the evaluation and SDP boards as
detailed in this section.
Connect the EVAL-SDP-CH1Z SDP-H1 board to P1 (bottom)
on the EVAL-AD7768-4FMCZ evaluation board.
Warning
The evaluation software and drivers must be installed before
connecting the evaluation board and SDP-H1 board to the USB
port of the PC to ensure that the evaluation system is correctly
recognized when it is connected to the PC.
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EVALUATION BOARD SOFTWARE
4.
SOFTWARE INSTALLATION PROCEDURES
The EVAL-AD7768-4FMCZ evaluation kit includes a CD
containing software to be installed on the PC before using the
evaluation board.
Select the location to install the software, and then click
Next. Figure 4 shows the default installation locations,
which are displayed when the window opens. To select a
different installation location, click Browse.
There are two parts to the installation:
AD7768-4 evaluation board software installation
EVAL-SDP-CH1Z system demonstration platform board
drivers installation
Warning
14130-004
The evaluation software and drivers must be installed before
connecting the evaluation board and SDP-H1 board to the USB
port of the PC to ensure that the evaluation system is correctly
recognized when it is connected to the PC. When disconnecting
the board, it is important to follow the power-down sequence
outlined in the Powering Down the System Demonstration
Platform section.
Installing the Evaluation Board Software
Figure 4. Evaluation Board Software Installation:
Selecting the Location for Software Installation
To install the evaluation board software,
3.
5.
A license agreement appears. Read the agreement, select I
accept the License Agreement, and then click Next.
14062-005
2.
With the SDP-H1 board disconnected from the USB port of
the PC, insert the installation CD into the CD-ROM drive.
Double-click the setup.exe file to begin the evaluation
board software installation. The software is installed to
the following default location: C:\Program Files\Analog
Devices\AD7768-4-4.
A dialog box appears requesting permission to allow the
program to make changes to the PC. Click Yes.
14130-003
1.
Figure 3. Evaluation Board Software Installation:
Granting Permission for Program to Make Changes
Rev. 0 | Page 10 of 18
Figure 5. Evaluation Board Software Installation:
Accepting the License Agreement
A summary of the installation is displayed. Click Next to
continue.
7.
14062-006
6.
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Figure 6. Evaluation Board Software Installation:
Reviewing a Summary of the Installation
Rev. 0 | Page 11 of 18
A dialog box informs you when the installation is
complete. Click Next.
14062-007
EVAL-AD7768-4FMCZ User Guide
Figure 7. Evaluation Board Software Installation:
Indicating When the Installation is Complete
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EVAL-AD7768-4FMCZ User Guide
Installing the System Demonstration Platform Board
Drivers
3.
Click Install to confirm that you want to install the drivers.
After the installation of the evaluation software is complete, a
welcome window displays for the installation of the SDP drivers.
With the EVAL-SDP-CH1Z board still disconnected from
the USB port of the PC, make sure that all other
applications are closed, and then click Next.
14130-010
1.
Figure 10. SDP Drivers Setup: Granting Permission to Install Drivers
To complete the drivers installation, click Finish, which
closes the installation wizard.
14130-008
4.
Figure 8. SDP Drivers Setup: Beginning the Drivers Installation
Select the location to install the drivers, and then click
Next.
14130-011
2.
Figure 11. SDP Drivers Setup: Completing the Drivers Setup Wizard
Figure 9. SDP Drivers Setup: Selecting the Location for Drivers Installation
Rev. 0 | Page 12 of 18
Before using the evaluation board, you must restart your
computer.
14130-012
14130-009
5.
Figure 12. SDP Drivers Setup: Restarting the Computer
EVAL-AD7768-4FMCZ User Guide
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SETTING UP THE SYSTEM FOR DATA CAPTURE
Launching the Software
After completing the steps in the Software Installation
Procedures and Evaluation Board Hardware sections, set up the
system for data capture as follows:
After completing the steps in the Setting Up the System for Data
Capture section, launch the AD7768-4 software as follows:
2.
From the Start menu, click Programs > Analog Devices >
AD7768-4 Evaluation Software. The main window of the
software then displays.
If the AD7768-4 evaluation system is not connected to the
USB port via the SDP-H1 when the software is launched, a
connectivity error displays prompting the user to choose an
evaluation board (see Figure 14). Connect the evaluation
board to the USB port of the PC, wait a few seconds, click
Rescan, and then follow the on-screen instructions.
14130-014
2.
Allow the Found New Hardware Wizard to run after the
EVAL-SDP-CH1Z SDP-H1 board is plugged into the PC.
(If using Windows XP, the PC may need to search for the
SDP drivers. Choose to automatically search for the drivers
for the SDP board if prompted by the operating system.)
Check that the SDP-H1 board is connected to the PC
correctly using the Device Manager of the PC.
a. Access the Device Manager as follows:
i. Right-click My Computer and then click
Manage.
ii. A dialog box appears asking for permission to
allow the program to make changes to the
computer. Click Yes.
iii. The Computer Management box appears. Click
Device Manager from the list of System Tools
(see Figure 13).
b. The SDP-H1 board appears under ADI Development
Tools, which indicates that the driver software is
installed and that the board is connected to the PC
correctly.
Figure 14. Connectivity Error Alert
When the software starts running, it searches for hardware
connected to the PC. A dialog box indicates when the SDP-H1
board connected to the PC is detected, and then the main
window appears (see Figure 15).
14130-013
1.
1.
Figure 13. Device Manager: Checking That the Board Is Connected
to the PC Correctly
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14130-015
SOFTWARE OPERATION
Figure 15. Evaluation Software Main Window
Overview of the Main Window
MCLK
The main window contains the significant control buttons and
analysis indicators of the evaluation software.
The MCLK (Hz) control in the Configuration tab must match
the frequency of the ADC clock source.
Configuration Tab and AD7768-4 Block Diagram
VREF
The Configuration tab is the tab displayed by default when the
software first opens. An overview of the AD7768-4 block
diagram is shown, along with buttons that open pop-up menus
for quick configuration of the device.
The Ext. REF (V) in the Configuration tab control must match
the reference voltage of the ADC.
The Waveform tab displays captured waveform data. It also
contains options to save the resulting data and shows the output
header data from the conversion results.
The FFT and Histogram tabs show a more in depth analysis of
the output data. This data can be saved to a file.
ADC Reset
Clicking ADC Reset in the Configuration tab sends a reset
command to the ADC via the SPI, and resets the device to its
default configuration.
Header Data
Use the Registers tab to change the configuration of the
AD7768-4.
The Header Data area shows the header data output in the first
eight bits of a conversion. It conveys status information and the
channel number. Header data for each channel can be selected
by changing the Analysis Ch option.
Sample Button
Click Sample to start ADC sampling; results are reported in the
Waveform, FFT, and Histogram tabs. Set the mode of operation
using the Sampling Mode drop-down box; the mode can be
continuous sampling or a single run.
CRC Error indicates that an error has occurred, and a reset
is required.
Filter not settled indicates that the filter did not settle
before data was sampled.
Filter Type indicates the type of filter that has been selected.
Filter saturated indicates that filter saturation has occurred.
Number of Samples
The number of samples per channel is variable and can be
changed using the Samples control.
Note that the evaluation software has not been configured to
output the CRC check code.
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EVAL-AD7768-4FMCZ User Guide
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Waveform Tab
14130-016
The Waveform tab displays a time-domain graph of the
sampled data. Controls beneath the graph allow zooming and
panning. Amplitude information is given beneath the graph for
the analysis channel selected.
Figure 16. Example Header Data
Channel Enable/Disable Check Box
14130-018
The channel enable and disable check boxes, as shown in
Figure 17, individually enable channels for display and analysis.
Figure 18. Waveform Tab
14130-017
FFT Tab
Figure 17. Channel Enable/Disable Check Boxes
Help Button
Click the help button (the ? icon) to show information about
the AD7768-4 software. The help button is located in the top
right corner of the Configuration tab (see Figure 15).
The FFT tab shows a frequency domain graph of the sampled
data. Controls beneath the graph allow zooming and panning,
and control over amplitude and frequency scaling. Frequency
and amplitude information is given beneath the graph for the
selected analysis channel.
Status Indicator and Busy light
14130-019
The status bar at the bottom of the screen indicates the current
state of the AD7768-4 software. The Busy LED illuminates
when the software is busy performing an action. Refrain from
carrying out any more actions when this light is lit.
Figure 19. FFT Tab
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EVAL-AD7768-4FMCZ User Guide
Histogram Tab
14130-021
The Histogram tab shows a histogram of the sampled data.
Controls beneath the graph allow zooming and panning, and
control over amplitude scaling. Amplitude information is given
beneath the graph for the selected analysis channel.
Figure 21. Registers Tab
Figure 20. Histogram Tab
Registers Tab
The Registers tab allows precise control of the AD7768-4
registers, allowing them to be read back and written to. The
registers are grouped together and can be altered in a number of
ways, as shown in Figure 21. The register to be written to can be
selected from the register map, located on the left hand side of
the Registers tab. Individual register bits can be changed from
the register section, or the entire register can also be written to
by writing the required hexadecimal value. Drop-down options
can be selected from the Bitfields section, or the entire bitfield
can be written to with a hexadecimal value.
The precharge buffers operate differently then the other registers.
To change these registers, it is recommended to navigate to the
Registers tab, select Precharge Buffer 1 or Precharge Buffer 2
from the register map, and change the value of these registers
using the hexadecimal value located on the right hand side of
the Register section (see Figure 22). The software reads back
the status of the registers correctly; however, to change a bit to
0, for example, a 1 must be written to the given bit in the
register. See the AD7768-4 data sheet for more details.
14130-022
14130-020
Precharge Buffers: Register Operation
A particular register configuration can be saved to be loaded
again at a later time.
Figure 22. Enabling/Disabling the Precharge Buffers
Exiting the Software
To exit the software, click the red X at the top right hand corner
of the main window. Be sure to press the reset button on the
EVAL-SDP-CH1Z before the board is powered off.
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EVAL-AD7768-4FMCZ User Guide
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Example
In this example, a sample is taken and analyzed with the help
of the AD7768-4 software. The desired data is expected on
Channel 2 of the ADC.
The following equipment is required:
Audio Precision source (AP SYS-2722 or similar)
A PC
EVAL-AD7768-4FMCZ evaluation board
EVAL-SDP-CH1Z SDP-H1 controller board
12 V power supply for the EVAL-SDP-CH1Z
9 V power supply for the EVAL-AD7768-4FMCZ
To sample and analyze the data, take the following steps:
1.
2.
3.
4.
5.
Connect the evaluation board to the SDP-H1 board.
Set both LK1 and LK2 to Position B on the evaluation board.
Power up both boards, and then connect the SDP-H1
board to the PC via the USB cable supplied.
Start the AD7768-4 evaluation software. Wait for the Busy
indicator to turn off.
Configure the Audio Precision source to the following
settings, and connect the output to the Channel 2 input:
6.
Select a sine wave output and High Acc
Set the output to balanced float
Set the frequency to 1 kHz
Set the amplitude to 7.734 V p-p
If not using the default configuration ensure that MCLK (Hz)
and Ext. REF (V) on the software configuration tab are set
to match the clock frequency and reference voltage supplied
to the chip (by default, 32.768 MHz and 4.096 V).
7.
8.
Set the number of samples per channel to 32,768 (default).
Configure the registers as required using the pop-up menus
under the Configuration tab. For this example, the settings
are wideband filter, decimation by 32, fast power mode, and
MCLK divide by four (all default).
9. Click Sample to take a reading. Wait for the Busy indicator
to turn off.
10. The sampled data is now present in the data capture tabs
(Waveform, FFT, and Histogram tabs). Change between
each of these to view the results. In this case, select Channel 2
on the channel enable and disable check boxes to view the
desired data on Channel 2.
11. Under the FFT tab, the FFT analysis shows results like the
following:
SNR = 106.8 dB
THD = −120 dB
SINAD = 106.6 dB
Fund. Frequency = 1000 Hz
Fund. Amplitude = −0.5 dBFS
12. Change various settings and observe the output. For
example, set the number of samples per channel to 16,384.
13. Click Sample to take a reading. Wait for the Busy indicator
to turn off.
14. The sampled data is now present in the Waveform, FFT,
and Histogram tabs.
For input amplitudes close to full scale (for the fundamental
amplitude reading between 0 and −1 dBFS), the SNR and SINAD
values displayed are adjusted to reflect a full-scale input.
Rev. 0 | Page 17 of 18
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EVAL-AD7768-4FMCZ User Guide
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
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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
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registered trademarks are the property of their respective owners.
UG14130-0-3/16(0)
Rev. 0 | Page 18 of 18
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