SBAU436B January   2024  – February 2025

 

  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 EVM Analog Input Options
      1. 2.1.1 Differential SMA Inputs
      2. 2.1.2 Single-Ended SMA Inputs
      3. 2.1.3 Differential Input Pins
    2. 2.2 Power Supplies
    3. 2.3 ADC Connections and Decoupling
    4. 2.4 ADC Input Amplifiers
    5. 2.5 VCOM Buffer
    6. 2.6 Voltage Reference
    7. 2.7 Clock Tree
    8. 2.8 Digital Interfaces
    9. 2.9 Using the ADS1278EVM With an External Controller
  9. 3Software
    1. 3.1 ADS1278EVM Software Installation
  10. 4Implementation Results
    1. 4.1 Hardware Connections
    2. 4.2 GUI Settings for ADC Control
    3. 4.3 Time Domain Display
    4. 4.4 Frequency Domain Display
    5. 4.5 Histogram Display
  11. 5Hardware Design Files
    1. 5.1 Schematics
    2. 5.2 PCB Layouts
    3. 5.3 Bill of Materials (BOM)
  12. 6Additional Information
    1. 6.1 Trademarks
  13. 7References
  14. 8Revision History
  15. 9Revision History

2.9 Using the ADS1278EVM With an External Controller

The ADS1278EVM is designed for easy connection to an external controller. This design enables the user to test application code and firmware on the ADS1278 without having to develop a custom PCB. This section describes the specific connections required to use the ADS1278EVM with an external controller. Figure 2-10 shows the location of various headers and terminal blocks described in this section.

ADS1278V2EVM-PDK Connecting an External Controller to the ADS1278EVMFigure 2-10 Connecting an External Controller to the ADS1278EVM

First, complete the following steps to prepare the ADS1278EVM board for use with an external controller:

  1. Remove the PHI board if still connected to the EVM.
  2. Provide +6V and ground (GND) to terminal block J10 from an external bench supply. Make sure the external controller also connects to GND on the EVM.
  3. See Section 2.7 to connect an external clock to the ADS1278EVM. Alternatively, use the 27MHz oscillator included with the EVM by:
    1. Moving jumper JP1 to pins 2-3 (OSC_Y1) to enable the oscillator
    2. Moving jumper JP2 to pins 2-3 (EVMCLK) to select the oscillator
  4. Install jumpers on header J4 to configure the ADC. For example, install jumpers on MODE0, MODE1, FORMAT0, FORMAT1, and FORMAT2, while leaving CLKDIV open (high). These selections configure the ADC for high-speed mode, SPI interface, and dynamic TDM DOUT mode. See the ADS1278 data sheet for more information regarding the different modes of ADC operation.

Finally, make the following connections to enable digital communication between the ADS1278EVM and the external controller:

  1. Connect POCI (peripheral out, controller in) from the controller to the DOUT1 pin on header J6 on the EVM.
  2. Connect SCLK from the controller to the SCLK pin on header J6 on the EVM.
  3. Connect the DIN pin on header J6 on the EVM to GND, do not leave floating.
  4. Connect an I/O pin from the controller to the SYNC pin on header J6 on the EVM. This connection is needed for robust power-up reset. Alternatively, tie the SYNC pin to IOVDD for test purposes.
  5. Connect an I/O pin from the controller to the DRDY pin on header J6 on the EVM. DRDY is an output from the ADC, indicating when new data are ready to be clocked out of the ADC. As shown in Figure 2-11, the user-defined data collection routine monitors this pin (polling or interrupt) and only transfers data after a falling edge.
ADS1278V2EVM-PDK ADS1278 DRDY Pin BehaviorFigure 2-11 ADS1278 DRDY Pin Behavior