SBAA487 January   2021 ADS8664 , ADS8668 , ADS8674 , ADS8678 , ADS8684 , ADS8684A , ADS8686S , ADS8688 , ADS8688A , ADS8694 , ADS8698

 

  1.   Trademarks
  2. 1Introduction
  3. 2Phase Delay and Non-Simultaneous Sampling
  4. 3Averaging with Sequencer and Burst Sequencer mode
    1. 3.1 Averaging with Sequencer
    2. 3.2 Averaging with Burst Sequencer
  5. 4Verification and Measured Result
    1. 4.1 Phase Delay Measurement
      1. 4.1.1 Measured Phase Delay without Averaging – 50Hz Sinusoidal Fundamental Signal
      2. 4.1.2 Measured Phase Delay with Averaging – 50Hz sinusoidal fundamental signal
      3. 4.1.3 Comparison
    2. 4.2 AC Performance
  6. 5Summary
  7. 6References

4 Verification and Measured Result

GUID-20210106-CA0I-Z3CD-ZZ1N-KGHQXKPQ3ZRD-low.gif Figure 4-1 Test Setup

The test setup is shown in Figure 4-1. The precision signal generator provides a clean sinusoidal test signal to all input channels of the ADS8686S on the EVM board. Applying the same test signal to all input channels of the ADC ensures that the measured phase delay does not contain any phase differences between different signal sources. Therefore, the measured phase deference between different channels can truly reflect the phase delay caused by the channel switching on the multiplexer of the ADC.

The standard ADS8686SEVM has total 16 inputs for 2x8-ch ADCs on the ADS8686S. As an example, only the 8 input channels on ADC A are used in the test. The ADS8686SEVM board interfaces with a computer through an interface module called the Precision Host Interface (PHI) controller card, which is a part of the ADS8686SEVM-PDK package. The GUI software runs on the computer for data capture, processing and the Phase Analysis software integrated in the EVM GUI is designed and mainly used in the test.