2.3 nV/√Hz: Differential: Time Gain Control (TGC) DAC Reference Design for Ultrasound
Description
The TIDA-01427 reference design provides a solution for differential signal chain used for generating a time-varying control voltage (VCNTL) to drive multiple AFE devices in a parallel configuration. TI's low-noise analog front ends (AFEs) for medical ultrasound have a time gain control (TGC) feature that helps achieve best possible signal-to-noise ratio (SNR) for ultrasound applications. This reference design uses dual multiplying DACs (DAC8802) followed by current-to-voltage converters (OPA2209) to generate a 20-V swing. After filtering this 20-V swing with a multiple feedback filter (THS4130): it is attenuated to 1.5-V using a passive attenuator. The design can be powered using a ±15 or 5-V supply (onboard Fly-Buck converter LM5160 converts a 5-V input to ±15-V rails). The clean power suppplies for the entire signal chain are generated using the TPS7A39 and TPS7A47. The ±10-V references for the DAC are generated using the REF5010 and OPA2209.
Features
- Low-noise (2.3nV/√Hz): differential TGC signal enables AFE58xx series devices to amplify lower amplitude signals resulting in higher depth of penetration in ultrasound imagingEnables AFEs to resolve the data with lower noise resulting in high resolution ultrasound imagesFull signal chain propagation delay of Second-order Butterworth active low-pass filter with fc = 150 kHz helps smooth transition of control signalCapable of driving up to 64+ channels of AFEsConfigurable output common-mode voltage from 0 to 2.5V to support AFEs with different control voltage requirements
Applications
- Ultrasound smart probe
- Ultrasound scanner
Product Categories
- Data converters