GXSC ADC Compatible with AD7193 for Imaging Medical Devices

Computed tomography (CT) uses ionizing radiation technology, where the CT detector is the core component of the overall system architecture It consists of multiple modules, each of which converts incident X-rays into electrical signals that are routed to a multi-channel analog data acquisition system (ADAS) The ADAS must have extremely low noise performance to maintain good spatial resolution, reduce X-ray dose, and have extremely low current output for high dynamic range performance.

To avoid image artifacts and ensure good contrast, the converter front-end must have excellent linearity performance and be available in a low-power mode of operation to reduce the cooling requirements of thermally sensitive detectors.

The ADC must have a high resolution of at least 24 bits for better, clearer images and a fast sampling rate (as short as 100 μs) to digitize the detector readings, and the ADC sampling rate must support multiplexing so that fewer converters can be used and the overall system size and power consumption can be reduced. Combining these features, the GXSC 24-bit 4.8kSPS, Sigma-Delta ADC with PGA is perfectly suited for imaging medical device applications.

This GXSC ADC is a low-noise, low-drift and high-resolution 24-bit ADC with an integrated programmable gain amplifier (PGA) that provides a high-precision measurement solution for bridge sensors, thermocouples, and resistance temperature devices (RTDs), with performance that is 100% compatible with the AD7193.

It includes a low-noise PGA with gain selections from 1, 2, 4, 8, 16, 32, 64, and 128 modulators as well as programmable digital SINC 4/SINC3/fast build-up filters, and 50Hz/60Hz simultaneous rejection options. Output data rates can be configured from 4.7SPS up to 4800SPS, and the device offers a channel sequencer function that automatically measures four differential inputs or eight pseudo-differential inputs.