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This version (17 May 2024 08:15) was approved by Pranjali Agrawal.

EVAL-AD7194ASDZ Hardware Guide

Set-up Procedures

After following the instructions in the Software Procedures section, set up the evaluation and SDP boards as detailed in this section.

  • Warning: The evaluation software and drivers must be installed before connecting the EVAL-AD7194ASDZ evaluation board and EVAL-SDP-CB1Z board to the USB port of the PC to ensure the PC correctly recognizes the evaluation system.
  1. Connect the EVAL-AD7194ASDZ to the controller board
    1. Option A: Connect the EVAL-AD7194ASDZ to the EVAL-SDP-CK1Z
      1. Using the 120 pin connector
        • Screw the two boards together using the plastic screw-washer set included in the evaluation board kit to ensure that the boards are connected firmly together.
      2. Using the Arduino Connectors
    2. Option B: Connect the EVAL-AD7194ASDZ to the EVAL-SDP-CB1Z
      • Using the 120 pin connector
        • Screw the two boards together using the plastic screw-washer set included in the evaluation board kit to ensure that the boards are connected firmly together.

Block Diagram

Hardware Link Options

Link Numbers Colour Default Position Descirption
LK1 Black Uninserted REFIN+ to AVDD/EXC
LK2 Black Inserted AVDD to AVDD/EXC For Brdige Connection
LK7 Black A DVDD voltage select:
Pos A: DVDD is connected to 3.3V
Pos B: DVDD is connected to AVDD
LK8 Black A IOVDD voltage select:
Pos A: sets IOVDD to 3.3v LDO supply
Pos B: sets IOVDD to external source
LK9 Black C AVDD voltage select:
Pos A: sets AVDD to 3.3v LDO supply
Pos B: sets AVDD to external source
Pos C: sets AVDD to 5V LDO Supply
LK10 Black Uninserted Used as external AVDD voltage connector for scp boards
LK11 Black Uninserted Used as external IOVDD voltage connector for scp boards
LK12 Black AUsed for stacking of Eval boards. To select Eval board(CS_N):
Pos A(1-2): selects eval board 1 (CS_ARD_1)
Pos B(2-3): selects eval board 2 (CS_ARD_2)
LK13 Black Uninserted This link shorts AIN1 to AIN2. This is useful to perform noise tests on the AD7194

On Board Connections

Bridge Connections

Connector P2: DC (Analog Input)

Functionality:

  • Bridge Connection
Connection Function
1 AIN 13 without DC filtering
2 AIN 14 without DC filtering
3 External Reference +
4 External Reference -
5 AIN 15 with DC filtering
6 AIN 16 with DC filtering
7 Excitation+
8 Ground/Sheild

Functionality:

  • Low Noise Test

-ALL INSERTED

Connection Function
1-2 AVDD
3-4 AIN1
5-6 AIN2

External Powers

Connector Function
P4 Pin 1-2 External IOVDD connection
P4 Pin 3-4 External AVDD connection
LK10 External AVDD connection for SCP Boards
LK11 External IOVDD connection for SCP Boards

Digital Connectors

SDP 120 Pin Connector P5Function Arduino connector P6,P7,P9,P10
3,4 GND P7-6,P7-7
5 V_USB P7-5
6,11,17,23,28,36,40,46,52 GND P9-7
56 EEPROM_A0 -
58,63,69,75 GND -
78 SYNC_INP10-5
79 SCL P10-10
80 SDA P10-9
81 GND -
82 SCLK P10-6
83 SDO/MSIO P10-5
84 SDI/MOSI P10-4
85 CS_N P9-3,P9-2
86,93,98,109,115 GND -
116 VIO P7-2
117,118 GND -

PMOD Connector P11

Connection Function Connection Function
1 CS_N 7 -
2 DIN 8 -
3 DOUT 9 -
4 SCLK 10 -
5 GND 11 GND
6 IOVDD 12 IOVDD

SMB Connections

There are 3 SMB connections on the board. To allow clock signals and reference into the board.

  1. J1 Provides option for External Reference+
  2. J2 Provides option for External Reference-
  3. J3 Brings external MCLK to the AD7193

Power Supplies

The evaluation board receives power through the controller board when connected to the PC via USB. Linear regulators generate the required power supply levels from the applied USB voltage.

AVDD (LK9) selection

  1. 5V supply (DEFAULT)
  2. 3.3V supply
    • 3.3V regulator supplies AVDD ADP150
  3. External AVDD
    • Connections on Connector P4

DVDD (LK7) selection

  1. 3.3V supply (DEFAULT)
    • 3.3V supplies DVDD
  2. AVDD
    • AVDD connected to DVDD

IOVDD (LK8) selection

  1. 3.3V supply (DEFAULT)
    • 3.3V regulator supplies IOVDD ADP150
  2. External IOVDD
    • Connections on Connector P4
  3. V_IO from SDP
    • R38 to be mounted

Serial Interface

There are four primary signals: CS, SCLK, SDI, and SDO/RDY (all are inputs, except for SDO/RDY, which is an output).

Serial communication options

  1. SDP-B board and the respective 120 pin SDP connector.
    • When using the SDP-B connection (120 pin) The evaluation board connects via the serial peripheral interface (SPI) to the Blackfin® ADSP-BF527 on the SDP-B board.
  2. Arduino connection SDP-K1
  3. PMOD connector
  4. Standalone mode

For an introduction to the Serial Peripheral Interface (SPI), click here

Reference Options

  1. DEFAULT ADR4525 On Board external reference on REFIN1+
  2. LTC6655LN-2.5/LTC6655LN-4.096 On Board external reference on REFIN+
    • Option to use ultra low noise reference
  3. External Reference on REFIN1+ Connector J1
  4. AVDD as Reference via R25
  5. External reference can be supplied on P3-4 and P3-5 for REFIN2+ and REFIN2-

Selecting the reference source:

Software

Board should be correctly connected to ACE

  1. Option A: Open AD7193 memory map

Search for the Configuration register

  1. Set the REFSEL[] to the desired reference source by using these bits
    1. REFSEL[0]: External reference applied between REFIN1(+) and REFIN1(−).
    2. REFSEL[1]:External reference applied between P1/REFIN2(+) and P0/REFIN2(-) pins.
  2. Option B: Open AD7194 Chip View
    1. Right click on ADC block
    2. Select Reference Source from the Reference Select option given as highlighted(1) below in the picture.
    3. Click on Apply Changes as highlighted(2) below.

GPIOs

The General purpose inout pins are powered by AVDD/AVSS. They can be used to provide AC-Excitation signals for AC-Excited sensors, using 2 or 4 outputs. Can be used to automatically control an external multiplexer. Other optional functions include Current Source outputs , 2nd Reference input.

GPIO Bit NameFunctionality
P3 P3DAT Digital Output P3
P2 P2DAT Digital Output P2
P1 P1DAT Digital Output P1/REFIN2+
P0 P0DAT Digital Output P0/REFIN2-

Evaluation board Connections and Functionality

The evaluation board highlights the functionality of the GPIOs

P0/REFIN2-

  • Available on the P3 connector.
  • Also used as secondary reference option.

P1/REFIN2+

  • Available on the P3 connector.
  • Also used as secondary reference option.

Schematics

Bill of Materials

resources/eval/user-guides/ad7194/hardwareguide.txt · Last modified: 05 Mar 2024 11:42 by Pranjali Agrawal