High-resolution, high-SNR true raw data conversion reference design for ultrasound CW doppler

The TIDA-01351 is a continuous wave (CW) signal conditioning subsystem for ultrasound imaging systems (64-, 128-, 192-, 256-channel ultrasound system). This design features 20-bit fully differential simultaneous sampling with true raw data available for processing. This TI Design consists of a fullydifferential signal path for I and Q channels, each using high-performance SAR analog-to-digital converters (ADCs) (ADS8900B), fully-differential precision amplifiers (THS4551), a dual low-noise, lowdropout (LDO) voltage regulator (TPS7A8801), and a precision voltage reference (REF5050). The TIDA-01351 can be interfaced with the PH1-EVM controller through the multiSPI™ digital interface, and the performance can be evaluated using a PC-based application (GUI) from any PC through the USB interface.

Features:

• Two simultaneous channels (I and Q) fully-differential signal chain providing zero-latency true raw data With SNR of 101.2dB and ENOB of 16.45
• 8-channel summing, filtering, buffering, and gain implemented in single-stage-high-bandwidth, low-power, low-noise, single supply
• High sampliing rate of 1 MSPS allows flexibility in post-processing to improve SNR and resolution
• Bandpass filtering for frequency range of 50 Hz to 20 kHz
• Operates from single 6-V power supply with total power consumption of 258 mW
• Designed using 20-bit, 1 MSPS SAR ADC (ADS8900B) with INL of 1ppm and SNR of 104.5dB

Parts include:

ADS8900B            20-Bit, 1-MSPS, SAR ADC with Internal Reference Buffer, Internal LDO & multiSPI™ Digital Interface 

OPA376                Precision, Low Noise, Low Iq Operational Amplifier 

REF5050               3 µVpp/V Noise, 3 ppm/°C Drift Precision Series Voltage Reference 

THS4551               Low Noise, Precision, 150MHz, Fully Differential Amplifier 

TPS7A88               Dual 1A Low-Noise (3.8-μVRMS) LDO Voltage Regulator 

Learn more by downloading the reference design below