ams AS5952M CT Sensor Module

Description

Product status: Pre-Production

The AS5952 is a sensor chip for 64-slice CT detectors that combines the photodiodes and the readout circuit on a single CMOS chip. This sensor solution, which includes an array of 32 x 8 photodiodes with ultra-low dark current and a 256-channel ADC side-by-side, allows the assembly of the pixel array on three adjacent edges of the device. Two AS5952 ICs can be placed in Z-direction enabling the design of CT detectors with 40 mm of Z-coverage in ISO center.

The AS5952 has a sensor dimension in Z-direction of 36.125 mm with a pixel dimension of 1.130x1.002 mm². Pixel dimensions can be customized on request. The sensor can be directly assembled on a substrate using a wire bonding process for manufacturing of a CT module.

Improved low dose performance can be achieved because of superior dark current of max. 1 pA due to the near zero offset voltage across the photodiode. The input-related noise is very low, a max. noise level of 0.36 fC can be reached including photodiode for an input current range of 200 nA.

The max. power dissipation of 1.46 mW per channel in normal mode and 1.23 mW per channel in low power mode reduces self-heating effects and lowers the overall cost of cooling the system. An internal reference voltage and bias generator reduces the bill of material. Featuring on-chip photodiodes, the AS5952 offers a cost-optimized solution for 64-slice CT detectors.

The digital data readout can be accessed via a 110 MHz LVDS interface. A SPI interface is used for device configuration such as mode of operation, input current range, selection of reference voltage and enabling the calibration mode. An integrated temperature sensor enables monitoring of the junction temperature. The AS5952 is delivered as die on foil on frame.

In addition we are offering the AS5952M. This module consists of 3x AS5952 integrated circuits, which are mounted onto a substrate and connected with wire bonding protected by glob top. The interface is on the bottom side through a flex connector that accepts a standard 0.3 mm thick Flexible Printed Circuit (FPC). All required passive components are located on the bottom side of the substrate. The module is available both with and without scintillator array. Watch the product video

Details

Features

  • Automatic zero offset voltage calibration across photodiode for ultra-low dark current
  • Monolithic integration of 256-channel ADC and photodiode array in one sensor
  • Integrated reference voltage and bias current generator for low bill of material
  • Two power modes for min. integration time of 80 μs and 200 μs
  • Calibration mode for external linearity calibration
  • Customization of pixel dimensions on request

Benefits

  • Ultra-low dark current of max. 1 pA
  • Lowest input related noise of max. 0.36 fC at 200 nA input range
  • Fast integration time of min. 80 μs
  • Low power dissipation of 1.23 mW/Ch at 200 μs and 1.46 mW/Ch at 80 μs
  • High ADC linearity of ±600 ppm including photodiode
  • 110 MHz LVDS interface for data streaming

Parameters

Channels
input
256
Integration time
min.
80 µs
Input related noise
0.36
Power consumption per channel
min.
1.23 mW
Resolution
26 bit
Package
module on substrate
Function
x-ray sensing