Features and Benefits

  • 256-channel, charge-to-digital converter
  • 16-bit resolution with no missing codes
  • Simultaneous sampling
  • User adjustable full-scale range up to 32pC
  • Down to 22 µs line time
  • Ultralow noise: 560 e at 2pC range
  • INL ±2.5lsb or 57.5ppm , ADC included
  • Multiple functional power modes: from 1mW/ch to 3mW/ch
  • Multiple sleep and power modes down to 0.005mW/ch
  • Capable of measuring electron or hole collected charge
  • See data sheet for additional features

Product Details

The ADAS1256 is a 256-channel, charge-to-digital analog-front end (AFE) mounted on high density flex. It can be directly mounted on a digital X-ray panel. It is suitable for a large variety of digital X-ray and photodiode array applications and it works with both hole sensing and electron sensing panels. ADAS1256 allows up to 22us line time, so it can be used in dynamic imaging panels in addition to still image panels. It contains 256 low power, low noise, low input current integrators with correlated double sampling stages; along with integrated true 16 bit high speed ADCs.

All converted channel results are output on a single LVDS self-clocked serial interface that significantly reduces external hardware. An SPI-compatible serial interface allows configuration of the AFE using SDI input. The SDO output allows the user to daisy chain several AFEs on a single 3-wire bus.

An integrated AFE timing sequencer controls the sampling activity of the analog front end (AFE). The sequencer is programmed via the SPI port and is timed by a single clock, ACLK.


  • Digital X-ray panel
  • Photodiode sensors array
  • CT Scanner
  • High channel count data acquisition systems (current or voltage input)
  • TFT panel readout
A short-form datasheet for this product is available for download from this web page. Complete documentation including detailed hardware and software guides are available upon completion of a Non-Disclosure Agreement (NDA) (pdf). Send your completed forms by e-mail to ADAS@analog.com. Additional support is available from your Analog Devices local sales.

Please contact the ADC Development Group for additional technical information.

For additional ADI Healthcare Products and related information, please visit www.analog.com/healthcare

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.