107 Bonaventura Dr., San Jose, CA 95134
Tel: +1 408 432 9888 – Fax: +1 408 432 9889
www.x-scanimaging.com

Linear X-Ray Photodiode Detector Array with Signal Amplification

XB8816R Series
An X-Scan Imaging XB8816R linear detector array is constructed of CMOS silicon photodiode array detector
chips mounted on a single printed-circuit board. The imaging circuit of each detector chip consists of acontiguous linear array of photodiodes, a timing generator, digital scanning shift register, an array of charge
integrating amplifiers, sample-and-hold circuits, and signal amplification chain. Each detector array generates anEnd-Of-Scan (EOS) pulse that can be used to initiate the scanning of the next detector array. Thus, a longer,continuous detector array can be formed from a daisy chain of smaller detector arrays.
For x-ray scanning applications, a scintillator material tailored to the user’s application is attached to the surfaceof the detector array to convert x-ray photons into visible light for detection by the photodiode array. The
XB8816R photodiode array is uniquely designed and processed to reduce radiation damage from the x-ray flux.
The signal processing circuits are positioned 2 mm away from the photodiode array. These circuits are shieldedfrom direct x-ray radiation using an external heavy-metal shield. The precision alignment of the metal shieldwith respect to the signal processing circuits is performed at the factory using a special molded housing and chipon-board (COB) technology.

Key Features• Large element pitch resolution of 1.6 mm• Different array lengths available:
o 2.0 inches (32 pixels)
o 4.0 inches (64 pixels)o etc.
• 5-V power supply operation• Simultaneous integration by using an array of charge integrating amplifiers• Sequential readout with a digital scanning shift register (Data rate: 1 MHz max.)• Integrated CDS circuits allow low noise and wide dynamic range up to > 4000
• User-specified scintillator material GOS:Tb, CsI:Tl, CdWO4, etc.
• Extended radiation hardness lifetimes

Applications• Linear x-ray imaging for industrial and food inspection• Linear x-ray imaging for homeland security and cargo screening1© 2014 X-Scan Imaging Corp.

Dec 2014, Rev. 1.1

Photodiode Detector with Signal Amplification XB8816R Series■ Mechanical specifications
Parameter
Element pitch
Element diffusion width
Element height
Number of elements
Active area lengthSymboli
PW
H––

XB8816R-2.0ii
1.6
1.565
2.4
32
51.2

XB8816R-4.0iii
1.6
1.565
2.464
102.4

Unit
mm
mm
mm
–mmi

Refer to enlarged view of active area figure.
2-inch long detector is specified here. Other lengths (at multiples of 0.5 inches) are available upon request.
iii
4-inch long detector is specified here. Other lengths (at multiples of 0.5 inches) are available upon request.
ii■ Enlarged view of active area

■ Absolute maximum ratings
Electronic device sensitive to electrostatic discharge and x-ray radiation. Although this device features ESD
protection circuitry, permanent damage ranging from subtle performance degradation to complete device failure
may occur on devices subjected to high-energy electrostatic discharges. Furthermore, although this device
features radiation shielding for protection against anticipated x-ray radiation, permanent damage ranging from
subtle performance degradation to complete device failure may occur on devices subjected to unanticipated xray radiation (e.g. off-axis or extremely high energy radiation). Therefore, proper precautions against ESD andx-ray radiation must be taken during handling and storage of this device.

Parameter
Supply voltage
Reference voltage
Digital input voltages
Operating temperatureiv
Storage temperatureiv

2Symbol
VDD
VREF
ToprTstg

Min
–0.3
–0.3
–0.3
–5
–10

Max
+6VDD + 0.3
VDD + 0.3
+60
+70

UnitVVVoCoC

Humidity must be controlled to prevent the occurrence of condensation.

Dec 2014, Rev. 1.1

Photodiode Detector with Signal Amplification XB8816R Series■ Recommended terminal voltage
Parameter

SymbolVDD
VREF

Supply voltage
Reference voltage

Min.
4.75
–Typ.
54.50

Max.
5.25
–UnitVV■ Electrical characteristics [Ta = 21oC, VDD = 5 V]
Parameter
DigitalClock pulse frequencyv
Digital input voltagevi

High level
Low level

Digital input capacitance
Digital input leakage current
High level
Low level
Digital output load capacitanceAnalogReference voltage input impedanceviii
0:0
Charge amplifier feedback
0:1
capacitanceix
1:0(PG2:PG1)
1:1
Video output impedanceVideo output load capacitancePowerPower consumption
Digital output voltagevii

Symbol

Min.

Typ.

Max.

Unit

f(CLK)
Vih
VilCi
Ii
Voh
Vol
Co

40
VDD–1.00
0––10
VDD–0.75
0––
VDD
040
+10
VDD
0–

4000
VDD
0.4––
VDD
0.4
50

KHz
V
V
pF
µA
V
V
pF

Rref
Cf00
Cf01
Cf10
Cf11
Zv
Cv

–––––––

516
8
4
2
1–––––––
100

KΩ
pF
pF
pF
pF
KΩ
pF

P–200–mWv

Video rate is 1/4 of clock pulse frequency f (CLK).
Digital inputs include CLK, RESET, EXTSP, PG2, and PG1.
vii
Digital outputs include Trig and EOS (see pin connections).
viii
Reference voltage input impedance is dependent on length of detector. For a 2-inch detector (XB8816R-2.0), the input impedanceis 5 KΩ.
ix
The sensitivity selection pins (see PG2:PG1 pin connections) control the sensitivity of the detector by selecting the pixel charge
amplifier feedback capacitance from Cf00 to Cf11. At Cf00, the detector has lowest sensitivity. At Cf11, the detector has highest
sensitivity.
vi

3Dec 2014, Rev. 1.1

Photodiode Detector with Signal Amplification XB8816R Series■ Radio-opto-electrical characteristics [Ta = 21oC, VDD = 5 V]

Parameter
Output offset voltage
Dark offset voltagexi

Max.
–40
––––
10

–

0.75

––

2.00

–

3.0

–

–

Symbol

xVos
Vd
1:1
1:0
0:1
0:0xiiX-ray sensitivity(PG2:PG1)S

Photo response non-uniformityxiii
Noisexiv

Min.
––40–––––10

XB8816R(1.6mm)Typ.
VREF–120006000
3000
1500–PRNU

PG2:PG1 = 0:0
PG2:PG1 = 1:1

Saturation output voltage

NVsatUnitVmV

V/R%mVrmsVx

Video output is negative-going output with respect to the output offset voltage.
Difference between output signal under dark conditions and Vref with an integration time of 1 ms.
xii
Sensitivity is dependent on x-ray source. Other scintillations with different sensitivity are available.
xiii
Measured without scintillation. When the photodiode array is exposed to uniform light which is 50% of the saturation exposure,the Photo Response Non Uniformity (PRNU) is defined as follows:
PRNU = ∆X ÷ X × 100%
where X is the average output of all elements and ∆X is the difference between the maximum and minimum outputs.
xiv
Measured with a video data rate of 750 KHz and an integration time of 1 ms in dark state.
xi■ Output waveform of one element
Dark State

Saturation Output
Voltage (Vsat)

Output Offset
Voltage (Vos)

Saturation StateGND

4

Dec 2014, Rev. 1.1

Photodiode Detector with Signal Amplification XB8816R Series■ Block diagram
EXTSP
4
RESET 1VDD
6GND
7Timing Generator

3TRIG

Shift Register

8EOS

VREF 10

Hold Circuit

9VIDEOVMS
PG0 5Charge Amplifier Array

CLK 2

PG1 111PG2 122345N-1 N

Photo Diode Array■ Timing chartxv
12345 14 15 16 17 18 19 201234567

CLK

tplw (RESET)
RESET

tphw (RESET)~7.5 Clocks~6.5 Clocks
Integration Time

Video Output Period
VIDEO

12n-1nTRIG

EOS

5Dec 2014, Rev. 1.1

Photodiode Detector with Signal Amplification XB8816R Seriestf (CLK)

tr (CLK)

tplw (CLK)thtphw (CLK)
th

ts

ts

tplw (RESET)

tf (RESET)

Parameter
Clock pulse low/high width
Clock pulse rise/fall times
Reset pulse low widthxvi
Reset pulse high widthxvii
Reset pulse rise/fall times
Reset pulse setup timexviii
Reset pulse hold time

tphw (RESET)

tr (RESET)

Symboltplw (CLK), tphw (CLK)tr (CLK), tf (CLK)tplw (RESET)
tphw (RESET)
tr (RESET), tf (RESET)
ts
th

Min.
100
012 / f(CLK)
20040
40

Typ.
–
2016 / f(CLK)
–
20––

Max.
–30––
30––

Unit
nsnsms
µs
ns
ns
nsxv

The falling of Video just before the 19th falling edge of CLK after transition of RESET from High to Low corresponds to the firstpixel. The video output for the first pixel should be read around the 20th falling edge and before the subsequent rising CLK edge while
Trig is high. After the first pixel, a pixel output appears on Video at every 4th clock cycle.
Care should be taken to prevent the rising edge of the RESET during the video output. Improper positioning of the RESET edgescan lead to interference with the read-out.
The falling edge of the RESET should follow the last pixel of the previous line’s read-out. Thus, one cycle of RESET pulses cannot
be set shorter than the time equal to (17 + 4 × N) clock cycles, where N is the number of pixels.
EOS of each detector chip appears during the output of the last pixel.
xvi
RESET must stay Low [tplw(RESET)] for at least twelve clock cycles.
xvii
The falling edge of RESET pulse determines the end of the integration time and the start of signal read-out, while the rising edge of
the RESET pulse determines the start of the integration time. As a result, the signal-charge integration time can be controlled
externally with the width of the RESET pulse [tphw(RESET)]. However, the charge integration does not start at the rise of a RESET
pulse but starts at the 8th falling edge of clock after the rise of the RESET pulse and ends at the 7th falling edge of clock after the fall of
the RESET pulse.
xviii
The rising and falling edges of RESET must observe the setup and hold time requirements around the falling edges of CLK.

6Dec 2014, Rev. 1.1

Photodiode Detector with Signal Amplification XB8816R Series■ Mechanical drawingsxix

xix

Unit: Dimensions are in millimeters (mm).
Board: FR4 epoxy resin bonded glass fabric.
Connector: BISON Advanced Technology Corp., Ltd. (www.bison-protech.com), P101-RGP-060/030-12 or similar.

■ Pin connections

Pin No.
12
345678
91011127

SymbolRESETCLKTRIG
EXTSP
VMS
VDD
GND
EOS
VIDEO
VREF
PG1PG2NameReset Pulse
Clock Pulse
Trigger Pulse
External Start Pulse
Master/Slave Selection
Supply Voltage
GroundEnd of Scan
Video Output
Reference Voltage
Sensitivity Selection
Sensitivity Selection

Description
Negative-going pulse input
Pulse input
Positive-going pulse output
Pulse/voltage input
See sensitivity selection table
5-V supply voltage
Common ground voltage
Negative-going pulse output
Negative-going output with respect to VREF
Voltage input
See sensitivity selection table
See sensitivity selection table

Dec 2014, Rev. 1.1

Photodiode Detector with Signal Amplification XB8816R Series■ Sensitivity Selection Table
Sensitivity Mode12
3
4

PG2GND
GND
VDD
VDD

PG1
GND
VDD
GND
VDD

Relative Sensitivity
1/8
1/4
1/2
1

■ Master/slave selection with start pulse EXTSP settings (VMS=GND)
For most applications, multiple detectors are read out in parallel. To ensure parallel read out, set the EXTSP
inputs of all detectors to LOW (A in the table below).
In applications where two or more linearly connected detectors are read out sequentially (in series), set thefirst detector’s EXTSP to LOW while connecting the EXTSP input of each subsequent detector to the EOS
output of each respective preceding detector (B in the table below). The CLK and RESET pulses should beshared among all detectors and the Video output terminals of all detectors are connected together. Themaximum number of detectors that can be daisy-chained together is limited by the maximum Video output
capacitance requirement.

A

B

Operation Mode
Master configuration:
Parallel readout: all detectors
Serial readout: 1st detector only
Slave configuration:
Serial readout: 2nd and later detectors

EXTSPLOW
Preceding detector’s EOS should be input■ Master/slave selection voltage VMS and external start pulse EXTSP settings
For most applications, multiple detectors are read out in parallel. To ensure parallel read out, set the VMS
input of all detectors to VDD (A in the table below).
In applications where two or more linearly connected detectors are read out sequentially (in series), set theVMS input of the first detector to VDD and the VMS input of each subsequent (second and later) detector toGND while connecting the EXTSP input of each subsequent detector to the EOS output of each respective
preceding detector (B in the table below). The CLK and RESET pulses should be shared among all detectors
and the Video output terminals of all detectors are connected together. The maximum number of detectorsthat can be daisy-chained together is limited by the maximum Video output capacitance requirement.

AB

8Operation Mode
Master configuration:
Parallel readout: all detectors
Serial readout: 1st detector only
Slave configuration:
Serial readout: 2nd and later detectors

VMS

EXTSP

VDD

Don’t care

GND

Preceding detector’s EOS should be input
Dec 2014, Rev. 1.1

Photodiode Detector with Signal Amplification XB8816R Series■ Readout circuit
In order to minimize noise and to maximize performance, an operational amplifier should be placed close tothe detector to amplify the Video signal.

Information furnished by X-Scan Imaging is believed to be accurate and reliable. However, no responsibility is assumed by X-Scan Imaging Corporation for its use.
Users are responsible for their products and applications using X-Scan Imaging components. To minimize the risks associated with users’ products and applications,users should provide adequate design and operating safeguards. No responsibility is assumed by X-Scan Imaging Corporation for any infringements of patents orother rights of third parties that may result from the use of the information. No license is granted by implication or otherwise under any patent or patent rights of XScan Imaging Corporation.
© 2014 X-Scan Imaging Corp.

Tel: +1 408 432 9888

9107 Bonaventura Dr., San Jose, CA 95134, U.S.A.
Fax: +1 408 432 9889

www.x-scanimaging.com

Dec 2014, Rev. 1.1