SBAU351 April   2021

 

  1.   Trademarks
  2. 1EVM Overview
    1. 1.1 ADS127L11EVM Kit
    2. 1.2 ADS127L11EVM Board
    3. 1.3 ADS127L11EVM-PDK-GUI Unsupported Features
  3. 2EVM Analog Interface
    1. 2.1 EVM Analog Input Options
    2. 2.2 ADC Connections and Decoupling
    3. 2.3 ADC Input Drive Amplifiers
    4. 2.4 VCOM Buffer
    5. 2.5 Onboard Voltage Reference
    6. 2.6 External Voltage Reference
    7. 2.7 Clock Tree
  4. 3Digital Interface
    1. 3.1 Serial Interface (SPI)
    2. 3.2 I2C Bus for Onboard EEPROM
  5. 4Power Supplies
    1. 4.1 Power Connection and Configuration
    2. 4.2 Low Dropout Regulator (LDO)
  6. 5ADS127L11EVM Software Installation
  7. 6EVM Operation
    1. 6.1 Connecting the Hardware
    2. 6.2 Optional Connections to the EVM
    3. 6.3 EVM GUI Global Settings for ADC Control
    4. 6.4 Time Domain Display
    5. 6.5 Frequency Domain Display
    6. 6.6 Histogram Display
  8. 7Bill of Materials, Schematics, and Layout
    1. 7.1 Bill of Materials
    2. 7.2 Board Layouts
    3. 7.3 Schematics
  9. 8References

ADC Connections and Decoupling

The circuit shown in Figure 2-1 shows all connections to the ADS127L11 data converter (U3). Each power-supply connection has a 1-μF and 100-nF decoupling capacitor. Make sure these capacitors are physically close to the device and have a good connection to the GND plane. The supply connections also have a series 0.1-Ω resistor. The purpose of this component is to facilitate current measurement for the ADC. Also, each digital input has a 10-Ω series resistor. These resistors smooth the edges of the digital signals so that they have minimal overshoot and ringing. Although not strictly required, these components may be included in the final design to improve digital signal integrity.

GUID-20210331-CA0I-JZ26-DMJF-QBBTQNCFVMDD-low.svgFigure 2-1 ADS127L11 Connections and Decoupling