Symbol |
Parameter |
Value |
Units |
Comment |
TA |
Ambient Temperature Range |
0-50 |
°C |
|
Φ |
Humidity |
<80 |
% |
Not condensing |
|
Altitude* |
<2000 |
m |
Above sea level |
IP |
IP rating |
IP40 |
|
With cover |
*for use in vacuum chamber, operate only with air pressure lower than 10
-3Pa Location: Intended for indoor use, dust free.
Electrical Specification
T
A = 25°C, USB voltage V
CC = 4.8V
Symbol |
Parameter |
Min |
Typ |
Max |
Units |
Comment |
VCC |
Supply Voltage |
4.0 |
5.0 |
5.5 |
V |
|
ICC |
Supply Current |
|
|
|
|
|
ICC1 |
Chip active |
|
800 |
1500 |
mA |
|
P1 |
Power Dissipation |
|
|
7.5 |
W |
|
I/O Conn. Input CMOS (pin 5,6,7,8,9) |
|
|
|
|
|
VINL |
Voltage Low |
-0.3 |
|
0.7 |
V |
|
VINH |
Voltage High |
1.7 |
|
2.8 |
V |
|
I/O Conn. Input LVDS (pin 3,4) |
|
|
|
|
|
VIN |
Voltage Range |
0 |
|
2.5 |
V |
|
VINDIFF |
Differential Voltage |
250 |
|
600 |
mV |
|
I/O Conn. +5V (pin 2) |
|
|
|
|
|
IMAX |
Maximum current |
0 |
|
1.15 |
V |
|
V+5V |
Pin Voltage |
|
4.5 |
|
V |
VCC – 0.5V |
Bias Voltage Source for Sensor Diode |
|
|
|
|
|
VBIAS |
Bias Voltage |
0 |
|
±450 |
V |
Polarity is sensor dependent |
Performance characteristics of Timepix3
Symbol |
Parameter |
Min |
Typ |
Max |
Units |
Comment |
f |
Hit-rate |
|
|
40 |
MPixels/s |
with USB 3.0 cable |
|
Data rate |
|
|
2.4 |
Gbit/s |
with USB 3.0 cable |
TREAD |
Frame Readout Time3 |
|
33 |
|
ms |
with USB 3.0 cable |
dT |
Time resolution |
1.56 |
|
|
ns |
|
FREAD |
Read-out frequency |
|
320 |
|
MHz |
½ of maximum ROC freq |
Pixel mode hit-rate measurement

The whole detector is exposed to homogenous perpendicular irradiation from X-ray tube operated at 18 kVp with 2 mm Aluminum filter. The measurement type is set to “Pixels” and mode to “ToT+ToA” all other parameters are set to factory defaults (as stored in configuration file delivered with device). The exposure time is set to 0.1 s. The “Clustering” tool of PiXet-Pro is used to analyze measured data. The number of hit pixels per second is drawn as function of X-ray tube current searching for saturation. The real number of events is verified for each step using frame type measurement when all hits are accumulated in single frame.
Sensor parameters
T
A = 25°C
Symbol |
Parameter |
Si |
CdTe |
Units |
Comment |
|
Thickness |
100 |
300 |
500 |
675 |
1000 |
µm |
|
σ |
Energy resolution of energy discrimination threshold (σ @ 23 keV) |
0.5 |
1.1 |
keV |
|
σ |
Energy resolution of energy discrimination threshold (σ @ 60 keV) |
0.6 |
1.5 |
keV |
|
σ |
Energy resolution in full spectral mode (σ @ 23 keV) |
0.7 |
3.0 |
keV |
|
σ |
Energy resolution in full spectral mode (σ @ 60 keV) |
1.0 |
3.6 |
keV |
|
|
Typical detectable energy range for X-rays |
5 to 60 |
5 to 500 |
keV |
See chart below |
|
Pixel size |
55 |
55 |
µm |
|
Basic principles, measurement types and modes
The ionizing radiation particle interacts with the sensor material creating an electric charge. This charge is collected by electric field and brought to pixel preamplifier where it is amplified and shaped forming triangular voltage pulse. The amplitude and duration of this pulse is proportional to energy deposited by particle within the pixel. The situation when the voltage pulse amplitude in particular pixel exceeds preselected threshold value is called “event” or “hit”. Each pixel contains three digital counters (10, 14 and 4 bits). These counters are used differently according to measurement type and mode. There are four basic values which can be measured and stored in counters of each pixel:
Measurement modes:
Number of Events |
number of events (hits) in the pixel during exposure time (this mode is suitable mainly for frame type readout) |
Time-over-Threshold (ToT) |
measured as number of periods of 40 MHz clock signal (25 ns step) when amplifier output signal stays over the energy threshold. The ToT can be transformed to energy in keV using per-pixel-calibration function. The coefficients for per-pixel-calibration are unique for each detector pixel and they are stored in configuration file delivered with device. The energy calibration is valid only for given values of other detector parameters as delivered in configuration file (especially threshold) |
Time-of-Arrival (ToA) |
number of periods of 40 MHz clock signal (25 ns step) from start of exposure till the event is registered by pixel (i.e. pulse in pixel crosses the threshold). The range is 409.6 µs. Additional 16 bits are added in FPGA in readout electronics so that the total range is 26.8 seconds. The additional bits are usable only if the pixel hit rate is below maximal value (see fp in table of Performance characteristics) |
Fast-Time-of-Arrival (FToA) |
time difference between event detection and next clock signal measured with step of 1.5625 ns. Range is 4 bits. The combination of ToA and FToA gives precise time of event detection in nanoseconds using following formula: Time [ns] = ToA*25 – FToA*1.5625 ToA and FTOA are combined together by software. If saved then ToA and FToA are stored as separate items |
Measurement types:
Frame type measurement No data is sent out of device during the exposure time. All measured events are accumulated in counters of pixels. Event counter is incremented and ToT is integrated for all events. The measured data is read-out after end of exposure time for all pixels with nonzero content. No measurement can be performed during readout process. Pixel type measurement Information about all hit pixels is read-out immediately and continuously during exposure time. If hit rate is below maximal value (see fp in table of Performance characteristics) then there is virtually no deadtime. Major modes and types of operation (rarely used combinations are shown with gray background):
Type |
Mode |
Range |
Description |
Frame (reading all pixels after end of exposure) |
Event+iToT |
10 bit + 14 bit |
2 output frames per exposure: 1st Events = Number of events in pixel, 2nd iToT = total time over threshold for all events in pixel. |
iToT |
14 bit |
1 output frame: iToT = total time over threshold for all events in pixel. |
ToA |
18 bit |
1 output frame: ToA+FToA3= Time of Arrival of first event in pixel. |
Pixel (reading only hit pixels continuously during exposure) |
ToT+ToA |
10 bit + 18 bit |
4 numbers per pixel per event: Position, ToT, ToA and FToA. |
ToA |
18 bit |
3 numbers per pixel per event: Position, ToA and FToA. |
Only ToT |
10 bit |
2 number per pixel per event: Position and ToT. |
Device description

+5VDC connector
Main power supply (via standard 5.5/2.1mm barrel connector). Connect after plugging USB connector.
USB 3.0 connector
USB type micro B, Standard USB 3.0 Super-Speed.
I/O Digital connector
Signals on I/O Digital connector are used for synchronization purposes. For details see Synchronization guide for TPX3. Input pins are NOT +5V compatible. Pin 2 (+5V) may be used for power of external circuitry. It is taken directly from +5VDC connector, protected by schottky diode (0.5A max) Pin directions (Input/output) are dependent on polarity of pin 9 (Dir Select).
Table for version APXMD3-Xxx170704
Pin |
Name |
Signal type |
Pin |
Name |
Signal type |
1 |
GND |
|
2 |
+5V |
|
3 |
Resersved |
CMOS 0-2.5V |
4 |
Resersved |
CMOS 0-2.5V |
5 |
Resersved |
CMOS 0-2.5V |
6 |
Resersved |
CMOS 0-2.5V |
7 |
NC |
– |
8 |
Resersved |
CMOS 0-3.3V |
9 |
NC |
– |
10 |
Resersved |
CMOS 0-3.3V |
Table for version APXMD3-Xxx180119
Pin |
Name |
Signal type |
Pin |
Name |
Signal type |
1 |
GND |
|
2 |
+5V |
|
3 |
CLK p |
LVDS (2.5V) |
4 |
CLK n |
LVDS (2.5V) |
5 |
E2 |
CMOS 0-2.5V |
6 |
E1 |
CMOS 0-2.5V |
7 |
Trigger Out |
CMOS 0-2.5V |
8 |
Trigger In |
CMOS 0-2.5V |
9 |
Dir select |
CMOS 0-2.5V |
10 |
GND |
|
Mechanical dimensions
Without protection cover
|
 |
All dimensions are in mm. |
|
With protection cover
|
 |
All dimensions are in mm. |
1 Convertors based on 6LiF or 10B4C for slow neutrons (efficiency up to 4%) or PE for fast neutrons.
2 During Readout time (or Dead time), no signal is collected from the sensor.
3 ToA and FToA are combined together by software automatically. If saved, ToA and FToA are stored as separate items (for Pixel type measurement).