256-channel, 24-bit current-to-digital converter targets CT scanning

July 31, 2014 // By Graham Prophet
Analog Devices has a current-to-digital converter module that doubles channel count while requiring 33% less area than alternative devices, and that mounts on standard PCB substrates.

Adding to its ICs for medical imaging, Analog Devices has introduced a current-to-digital converter module that reduces the cost and complexity of computed tomography (CT) scanner system design. ADAS1131 is a 256-channel, 24-bit current-to-digital converter module that is available in a 15-mm-square BGA package with a 0.8-mm pitch. The device uses approximately 33% less PCB area than alternative devices that offer only half the channel density. The 0.8-mm pitch packaging feature enables designers to mount the ADAS1131 on a standard PCB substrate, a less costly and higher yield option than high density, specialised PCB substrates requiring laser vias.

In addition to embedding 256 low-power, low-noise, low-input-current integrators, simultaneous sample-and-hold circuitry, and two high-speed A/D converters with configurable sampling rates, the ADAS1131 module incorporates all associated internal buffers, decoupling and by-pass capacitors for data acquisition. It consumes 3 mW of power per channel at any throughput, which is the same as competing devices that integrate only 128 channels. In a 15 × 15 mm 324-ball CSP-BGA package the device costs $304 (1000).

Analog Devices; www.analog.com/ADAS1131