UG000439 •v1-00 • 2020-Apr-21
1 Introduction
The AS585X product family (AS5850, AS5851 and AS5852) is a 16-bit, 256-channel low-noise
charge-to-digital converter designed for digital X-ray systems. It enables a wide range of applications
for digital X-ray including static and dynamic flat panel detectors (FPDs) used in radiographic imaging,
digital mammography and high-speed fluoroscopy.
Each of the devices consists of 256 analog charge sensitive amplifiers (CSA) with a programmable
full-scale range, a correlated double sampler (CDS) for offset compensation with programmable time
constant and 128 multiplexed analog-to-digital converters (ADC) for the digital readout of each pixel.
The device can be configured for electron and hole polarity and includes a voltage reference and a
temperature sensor. Built-in diagnostic modes enable error detection in the signal chain.
The converted channels are output on a single LVDS interface with a data rate up to 320 Mbps for
optimized line time. The serial SPI interface allows the configuration of the analog frontend including
timing and different power modes for low stand-by power consumptions and fast startup times.
AS5850 is a high-speed design, optimized for line times down to 19 μs for dynamic flat panel detectors
in fluoroscopy applications. The AS5851 and AS5852, optimized for line times down to 38 μs, 76 μs
respectively, are its low-power versions for static, portable, and battery supplied flat panels with
minimum power dissipations down to 1.4 mW per channel.
All devices are delivered per default on a Chip on Flex package to minimize sidewall distances and
allow direct assembly on the X-ray panel. The Flex design can be customized according to customer
requirements. Alternatively, all devices can be delivered as dice on foil.
1.1 AS585X Eval Kit
The AS585X Eval Kit (Eval Kit) is a stand-alone system, which allows the AS585X complete
configuration, the measurement of all the relevant parameter (like noise and input linearity) and the
connection to an X-Ray photodetector panel.
Two different AS585X samples are included in the Eval Kit in order to perform the complete
evaluation:
1. AS585X Chip-on-Board (COB) sample: The AS585X die is directly bonded to the AS585X
sample board, which is equipped with the signal generator circuitry. Such circuitry allows the
generation of the input signals that emulate the photodetector as on the final application.
2. AS585X Chip-on-Flex (COF) sample: The default package type of the AS585X, where the die is
bonded on a flex substrate. Such package allows the direct connection to an X-Ray
photodetector panel.
In order to connect the COF to the Base Board, an adapter board is included with the COF pre-
assembled.
