SLAU917B October   2023  – February 2024 AFE20408

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1 Hardware Setup
      1. 2.1.1 Hardware Theory of Operation
      2. 2.1.2 Jumper Definitions
      3. 2.1.3 Connector Definitions
      4. 2.1.4 Test Points
    2. 2.2 Hardware Overview
      1. 2.2.1 Electrostatic Discharge Caution
      2. 2.2.2 Connecting the FTDI Digital Controller
      3. 2.2.3 SPI Configuration
      4. 2.2.4 I2C Configuration
      5. 2.2.5 PAON Open Drain Circuit
  9. 3Software
    1. 3.1 Software Setup
      1. 3.1.1 Software Installation
    2. 3.2 Software Overview
      1. 3.2.1 Launching the Software
      2. 3.2.2 Software Features
        1. 3.2.2.1 Low Level Configuration Page
        2. 3.2.2.2 High Level Configuration Page
  10. 4Hardware Design Files
    1. 4.1 Schematics
    2. 4.2 PCB Layout
    3. 4.3 Bill of Materials
  11. 5Additional Information
    1.     Trademarks
  12. 6Revision History

2.1.1 Hardware Theory of Operation

The AFE20408EVM is connected to the computer through the on-board FTDI digital controller using the USB cable that is supplied with the EVM. The evaluation board features connectors and test points for all communication lines, DAC outputs, supplies, and the ADC inputs. Figure 3-1 shows a block diagram of the AFE20408EVM.

GUID-20231002-SS0I-05NZ-XPTT-MCQ4JM29C8N7-low.svgFigure 2-1 Theory of Operation Block Diagram

The USB connection provides the 5V supply to the EVM. A voltage regulator generates 3.3V from the USB 5V supply. These 5V and 3.3V supplies are used to power the FTDI controller.

The AFE20408 VDD supply can use the on-board 5V supply depending on the J13 pins 3-4 setting. By default, the VDD supply is connected to the on-board 5V supply. Alternatively, VDD can be supplied externally through banana jack J5. Remove the jumper connector on J13 pins 3-4 before connecting external supplies to VDD.

The AFE20408 VIO supply can use the on-board 3.3V supply depending on the J13 pins 1-2 setting. By default, the VIO supply is connected to the on-board 3.3V supply. Alternatively, VIO can be supplied externally through banana jack J8. Remove the jumper connector on J13 pins 1-2 before connecting external supplies to VIO.

The AFE20408 VCCA and VCCB supplies are used to configure the device to operate in the positive output range. If using the positive range, then power VCCA and VCCB externally using banana jacks J3 and J11, respectively. If using the negative range, then place a shunt on pins 1-2 of J2 and J9 to connect VCCA and VCCB to ground. Jumper J6 can be used to connect VCCA and VCCB together, allowing for the use of one external supply to power both VCCA and VCCB. Remove the jumper connections on pins 1-2 of J2 and J9 before connecting external supplies to VCCA or VCCB, respectively.

The AFE20408 VSSA and VSSB supplies are used to configure the device to operate in the negative output range. If using the negative range, then VSSA and VSSB can be powered externally using banana jacks J4 and J12, respectively. Alternatively, an on-board voltage regulator is available to provide negative voltage to the supplies. The regulator is powered by an external negative power supply, VNEG, and can output either –7 V or –10 V depending on the position of jumper J28. Jumper J29 connects the on-board negative voltage to the VSSA and VSSB supplies. If using the positive range, place a shunt on pins 2-3 of J2 and J9 to connect VSSA and VSSB to ground. Remove the jumper connections on pins 1-2 of J29 and J2/J9 before connecting external supplies to VSSA and VSSB.

There are multiple unpopulated components on the EVM that can be populated to change the configuration of the EVM:

  • R7 and R9 are I2C pull-ups to VIO. When using a communication source other than the FTDI controller for I2C communication, R7 and R9 can be populated for pull-ups to VIO.
  • R35 is a pull-down to ground for the PAON output. When operating the PAON output in push-pull mode, the R35 pull-down resistor can be populated to make sure the pin is grounded during startup and shutdown operation.
  • C6, C11, C18, and C20 are 0603 footprints to allow for larger capacitance loads on the DACA1, DACA3, DACB1, and DACB3, respectively.
  • J14, J15, J20, J21, J25, and J26 are optional terminal blocks. See Table 3-4 for more information.