Full-featured evaluation board for 10 lead PulSAR® ADCs Versatile analog signal conditioning circuitry On-board reference, reference buffers and ADC Drivers PC software for control and data analysis of time and frequency domain System Demonstration Board Compatible EVAL-SDP-CB1Z
Note that we are transitioning between versions of hardware, both of which are compatible with the SDP board. Some boards are available on REV A hardware, but all boards are migrating to REV C hardware over coming months
All devices will be migrating to REV C hardware. This board contains the on-board power supplies to power all portions of the board - the ADC, Reference, Amplifiers and SDP board. This board operates from a simple +9V wall adaptor which is included as part of the evaluation board kit. This board interfaces to the SDP controller board.
All documentation for this version of hardware is contained in the USER GUIDE REV C USER GUIDE
All detail which follows applies to REV A hardware
This evaluation board covers for the following 10 lead PulSAR® analog to digital converters (ADCs): AD7685(16-bit), AD7686(16-bit), AD7687(16-bit), AD7688(16-bit), AD7690(18-bit), AD7691(18-bit), AD7693 (16-bit), AD7942(14-bit), AD7946(14-bit), AD7980, AD7988-1, AD7988-5(16-bit), AD7982(18-bit), AD7983(16-bit), AD7984(16-bit). These low power ADCs offer very high performance of up to 18bits with throughputs ranging from 100ksps to 1MSPS. The evaluation board is designed to demonstrate the ADC's performance and to provide an easy to understand interface for a variety of system applications. A full description of these products is available in their respective data sheets and should be consulted when utilizing this evaluation board. The evaluation board is ideal for use with Analog Devices System Demonstration Board, (SDP). On-board components include a high precision buffered band gap 5.0V reference, (ADR435), reference buffers (AD8032), a signal conditioning circuit with two op-amps (ADA4841-1) and regulators to derive necessary voltage levels on board (ADP3334, ADP3303). This evaluation board interfaces to the SDP board via a 120 pin connector. SMB connectors, J3 and J4, are provided for the low noise analog signal source.
Evaluation Board Software version 1.1 is available to download.
The software install is a two part install, user should proceed through both parts prior to connecting board for first time
Install the software prior to connecting the SDP board to the USB port of the PC. This ensures that the SDP board is recognized when it connects to the PC.
The default location for the software is C:\Program Files\Analog Devices\10 Lead PulSAR ADCs This location contains the executable software, datasheets and example files.
Proceed through the install 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 SDP board to the PC. There are two portions to the software install. Firstly the software related to the evaluation board as shown in Figure 2. Figure 2. Evaluation Board Software Installation Launches
The second part of the software installation is the drivers related to the SDP board. These must be installed for the evaluation board to function correctly. See Figure 8 to Figure 13.
When you first plug in the SDP board via the USB cable provided, allow the new Found Hardware Wizard to run. You can check that the drivers and the board are connected correctly by looking at the Device Manager of the PC. The Analog Devices System Development Platform (32MB) should appear under ADI Development Tools.
The board consists of the specific ADC (U10) with reference (ADR435U6) and ADC Drivers (ADA4841-1 U8, U12) The evaluation board is a flexible design that enables the user to adjust compensation components in addition to operating from adjustable bench top power supply.
The evaluation board requires power from an external bench top supply, applied to J1 connector.
Table 1. External Power Supply Required (max 12V across +Vs to -Vs)
|Power Supply||Voltage Range||Purpose|
|+Vs||+7.5V||Supplies ADR435, regulator ADP3334 which supplies +7V to +Vs of ADA4841-1, regulator ADP3303 which supplies +5V to SDP|
|-Vs||-2V||Amplifier ADA4841-1 negative rail|
|Vdd||2.5V||ADC Supply Rail for following ADCs AD7980, AD7982, AD7983, AD7984, AD7988-5|
|5V||ADC Supply Rail for following ADCs AD7685, AD7686, AD7687, AD77688, AD7690, AD7691, AD7693, AD7694, AD7942, AD7946|
On board regulators generate required levels from the applied +Vs rail. The regulators used are the ADP3334 (U9) which supplies +7V for the +Vs of the ADC driver amplifier (ADA4841), while the ADP3303-5 delivers 5V to the SDP board connector, J2 to power the SDP board. The SDP in turn provides a 3.3V V_DRIVE which supplies the IOVDD of the ADC in addition to the logic gates (U1, U3, U4). Each supply is decoupled where it enters the board and again at each device. A single ground plane is used on this board to minimize the effect of high frequency noise interference.
The evaluation board uses the SPORT interface from the SDPBF527 DSP. A number of AND gates are used to clock and gate the SPORT transfer to the ADC device. See U1, U3, U4.
There is one 3 Solder Link Option on the board. It is configured depending on which generic of ADC is on the specific evaluation board as described below. Table 2. Solder Link Default Setting
The analog inputs to the evaluation board are J3 and J4 SMB (push on) connectors. These inputs are buffered with dedicated amplifier circuitry (U8 and U12) and discrete as shown in the schematic. The circuit allows for different configurations, input range scaling, filtering, addition of a DC component, use of different op-amp and supplies. The analog input amplifiers are set as unity gain buffers at the factory. The Amplifier positive rail is driven from +7V (from ADP3334, U9), this could be changed to a different value as required, the negative amplifier rail is driven from –Vs which is applied direct to the board. The range of supply possible is listed in Table 1. The default configuration sets both U8 and U12 at mid-scale generated from a buffered reference voltage divider (VCM). The evaluation board is factory configured for providing either a single ended path or a fully differential path as described in Table 2. For dynamic performance, an FFT test can be done by applying a very low distortion AC source. For low frequency testing, the Audio Precision source can be used directly as the outputs on these are isolated. Set the outputs for balanced and floating. Different sources can be used however, most are single ended and use a fixed output resistance. Since the evaluation board uses the amplifiers in unity gain, the non-inverting input has a common mode input with a series 590 ohm resistor and it needs to be taken into account when directly connecting a source (voltage divider).
To run the program, do the following:
Simply connect the EVAL board to the USB port of the PC, wait a few seconds, click Rescan, and follow the instructions.
The software connects to the board and displays the following:
Once the board has been correctly detected, the software panel will open. The example below shows the AD7691 panel.
The following is the description of the user panel:
Note the following documents apply to Rev A hardware