SBAU269C October   2016  – August 2021 ADS8900B

 

  1.   Trademarks
  2. 1EVM Overview
    1. 1.1 ADS8900EVM-PDK Kit Features
    2. 1.2 ADS8900EVM Features
  3. 2Analog Interface
    1. 2.1 ADS8900B Connections and Decoupling
    2. 2.2 ADC Amplifier Input Drive
    3. 2.3 Voltage Reference and VCM Scaling
  4. 3Digital Interface
    1. 3.1 multiSPI™ for ADC Digital I/O
    2. 3.2 I2C Bus for Onboard EEPROM
  5. 4Power Supplies
    1. 4.1 Positive Supply and Test Points
    2. 4.2 Negative Supply
  6. 5ADS8900EVM-PDK Initial Setup
    1. 5.1 Software Installation
    2. 5.2 Default Jumper Settings for Differential Inputs
    3. 5.3 Default Jumpers for Bipolar, Single-Ended Inputs
    4. 5.4 Default Jumpers for Unipolar, Single-Ended Inputs
    5. 5.5 External Source Requirements for ADS8900 Evaluation
  7. 6ADS8900EVM-PDK Operation
    1. 6.1 EVM GUI Global Settings for ADC Control
    2. 6.2 Register Map Configuration Tool
    3. 6.3 Time Domain Display Tool
    4. 6.4 Spectral Analysis Tool
    5. 6.5 Histogram Tool
    6. 6.6 Linearity Analysis Tool
    7. 6.7 ADS8900BEVM Support for ADS8910B and ADS8920B Devices
  8. 7Bill of Materials, PCB Layout, and Schematics
    1. 7.1 Bill of Materials (BOM)
    2. 7.2 PCB Layout
    3. 7.3 Schematics
  9. 8Revision History

5.2 Default Jumper Settings for Differential Inputs

The EVM can be jumper configured for both differential and single-ended inputs. The jumpers also impact the common-mode (offset) requirements for the input signal. Some jumpers are only used in unusual circumstances, and are normally configured as described in this section. Table 5-1 provides jumper configurations for differential inputs. Figure 5-5 shows the input full-scale signals and the ADC output.

Table 5-1 Jumper Configuration for Fully Differential Input
JumperDefault SettingPurpose
JP1RemovedWhen installed, this jumper forces input J2 to GND or VCM. This jumper is not installed for differential inputs but is installed for single-ended inputs.
JP2RemovedWhen installed, this jumper forces input J3 to GND or VCM. This jumper is not installed for differential inputs but can be installed for single-ended inputs.
JP32.6-V positionBoth the 2.5-V and 2.6-V position can be used for a fully differential input signal. The 2.6-V position shifts the signal from GND by 0.1 V to minimize distortion resulting from output swing limitations. This shift works because the amplifier positive supply is set to 5.3 V. The signal out of AINP and AINN ranges from 0.1 V to 5.1 V when the jumper is in the 2.6-V position. The signal out of AINP and AINN ranges from 0 V to 5.0 V when the jumper is in the 2.5-V position.
JP4GND positionThis jumper selects the negative supply voltage. The default board configuration does not include the negative supply, so the –0.2-V position does not work without installing U6 and the associated components.
JP5RemovedRemoving this jumper sets the EEPROM write protect on. The EEPROM is factory programed and does not need to be reprogrammed, so keeping the write protect on is recommended.
GUID-20201204-CA0I-CC75-9DRF-4QBQPCNCCLJZ-low.gifFigure 5-5 Differential Input Signal and Expected ADC Response