Do you want to measure extremely low currents? Then this new current-to-digital converter may be just the thing for you. The new device is intended to help Computed Tomography (CT) scanners to produce sharper, more detailed images that in turn will help physicians to produce more accurate diagnoses while subjecting patients to lower doses of radiation.

The new AS5900 detector interface chip for CT X-ray scanners from ams is ultra-low noise and requires only 3,200 electrons for a full-scale range at an input current of 1 µA and 30 pF input capacitance, enabling it to digitize extremely low-current outputs from the latest high-sensitivity photodiodes. The sigma delta ADC features 26-bit resolution while operating at high acquisition rates (for this kind of applications), and the adjustable integration time can be set as low as 50 µs. Other programmable features are gain, power mode and clock frequency.

The current-to-digital converter includes an internal reference voltage and temperature sensor, and provides a standard LVDS interface to a host FPGA, running at a data rate of up to 80 Mb/s. Curiously, the device is priced at $1.00 per channel, and it has 128 of them...