SBOA591A April   2024  – May 2024 ADS8881 , ADS8900B , ADS9224R , THS4551 , THS4552

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2CWD Block Diagram and Designs
    1. 2.1 Proposal 1
    2. 2.2 Proposal 2
    3. 2.3 Proposal 3
    4. 2.4 Proposal 4
  6. 3Comparison of the Designs
  7. 4Summary
  8. 5References
  9. 6Revision History

Proposal 4

Figure 2-11 shows, the ADS127L21 used in Proposal 4 is a 24 bits Delta-Sigma ADC with 1.365 MSPS in TI introduced in 2023, and since ADS127L21 does not have an internal reference, ADS127L21 also uses the REF70 as an external reference. This proposal has the highest quality signal-to-noise ratio and dynamic range based on the highest sample bits and over-sample technology. Designed for high-end ultrasound device CWD applications for the best image quality.

 Proposal 4 ADS127L21 and
                    THS4551 Figure 2-11 Proposal 4 ADS127L21 and THS4551
  1. Proposal 4 Noise Calculation

As shown from Figure 2-12, because the simulation models of the ADS127L21 has not released in TI.com, So we cannot do the simulation in PSPICE or TINA, but we can use the Analog engineer calculator to complete this. For more details, please refer to TI.com.

 Proposal 4 Noise
                    Performance Figure 2-12 Proposal 4 Noise Performance