Vertilon Corporation has made every attempt to ensure that the information in this document is accurate and complete.
Vertilon assumes no liability for errors or for any incidental, consequential, indirect, or special damages including,
without limitation, loss of use, loss or alteration of data, delays, lost profits or savings, arising from the use of this
document or the product which it accompanies.
Vertilon reserves the right to change this product without prior notice. No responsibility is assumed by Vertilon for any
infringements of patents or other rights of third parties which may result from its use. No license is granted by implication
or otherwise under the patent and proprietary information rights of Vertilon Corporation.
The SIB864 is powered with a +5V power source directly from Vertilon’s PhotoniQ multi-channel data acquisition
systems. A separate -100V power source from the PhotoniQ is used to generate the high voltage bias signal to the SIPM
array. Use with any other power sources may result in damage to the SIB864 or the SIPM array.
Operate Inputs within Specified Range
To avoid electric shock, fire hazard, or damage to the product, do not apply a voltage to any input outside of its
specified range.
Electrostatic Discharge Sensitive
Electrostatic discharges may result in damage to the SIB864. For this reason, the SIB864 board is intended to be
operated in a user’s conductive instrument enclosure.
Do Not Operate in Wet or Damp Conditions
To avoid electric shock or damage to the product, do not operate in wet or damp conditions.
Do Not Operate in Explosive Atmosphere
To avoid injury or fire hazard, do not operate in an explosive atmosphere.
Interface board for Ketek PA3325-WB-0808 8 x 8 SIPM array
Supports 64 parallel charge output channels from SIPM array
Leading edge discriminator for event trigger and timing
Adjustable gain and threshold for discriminator channel
High voltage circuitry to bias the SiPM array
Integrated temperature sensor
100% compatible with Vertilon’s PhotoniQ multichannel DAQs
Simplified control through PhotoniQ graphical user interface
User Guide
The SIB864 sensor interface board allows the Ketek PA3325-WB-0808 8 x 8 silicon photomultiplier (SIPM) array to easily
interface to a Vertilon PhotoniQ multichannel data acquisition system. The SIPM device is inserted into the bottom side of
the printed circuit board where the 64 cathode output signals are routed directly to the sensor interface board (SIB)
connectors. The SIB connectors conform to Vertilon’s standard, low-noise, multi-channel, cable interconnection system.
The connectors mate to a micro-coaxial cable assembly that passes the 64 device outputs to the PhotoniQ. Bias to SIPM
array is provided on a high voltage cable by the PhotoniQ where it can be enabled and configured through the PhotoniQ
graphical user interface. A special current-sense output from the bias interface circuitry is routed to the input of a variable
gain preamplifier on the SIB864 to represent the total AC current signal to all 64 SIPM channels. This signal, which is
available to the user on an SMB jack, is fed into a user-programmable threshold leading edge discriminator. The
discriminator generates a trigger signal on an SMB jack when an event exceeding a predefined energy threshold is
detected on the PA3325-WB-0808 device. The trigger output is typically connected to the trigger input of the PhotoniQ
data acquisition system where it is used to initiate the collection of the energy signals from the SIPM array connected to
the DAQ system’s inputs. Alternatively, it can be connected to external digital timing hardware such as a coincidence
detector. A temperature sensor located on the SIB864 provides a continuous readout of the ambient temperature near
the PA3325-WB-0808. The full functionality and operation of the SIB864 is conveniently controlled through the
PhotoniQ’s graphical user interface. Intelligent software in the PhotoniQ constantly monitors the status of its SIB
connectors to determine the type of sensor interface board attached to them. Once recognized, a dialog box specific to
the recognized SIB is made available in the GUI through which the user has complete control over its operation.
The various functions on the SIB864 are described in greater detail on the following pages. When necessary, refer to the
functional block diagram shown in Figure 1 below.
A typical radiation detection setup using a SIB864 is shown below. The Ketek PA3325-WB-0808 silicon photomultiplier
array is connected to the SIB864 which is positioned in an optical assembly to detect incoming radiation. The 64 outputs
from the SIPM array are routed on the SIB864 to the SIB connectors that connect to a PhotoniQ IQSP482 or IQSP582
multichannel data acquisition system. The discriminator channel on the SIB864 produces a trigger to the PhotoniQ
whenever a radiation event is detected on any of the SIPMs in the array. The energy level threshold for the radiation
event is set by the user through the PhotoniQ graphical user interface. Charge signals from the 64 cathodes of the
PA3325-WB-0808 device are acquired by the PhotoniQ for each trigger produced by the SIB864. Digitized output data
from the PhotoniQ is sent through a USB 2.0 connection to a PC for display, logging, or real time processing. In the figure
below, the PhotoniQ GUI is set to display an 8 x 8 image of the energy levels for each event captured.
Figure 2: Typical Radiation Detection Setup
PA3325-WB-0808 Detector Mounting
The SIB864 supports the Ketek PA3325-WB-0808 8 x 8 silicon photomultiplier array. This particular model of the device
is mounted to the bottom of the sensor interface board through two high density connectors. The SIPM device attached to
a SIB864 is shown below.
The 64 cathode signals from the PA3325-WB-0808 device are routed directly on the SIB864 to the SIB connector. These
signals connect to channels 1 through 64 of a Vertilon PhotoniQ IQSP482 or IQSP582 charge integrating data acquisition
system. The PhotoniQ utilizes DC-coupled high speed transimpedance amplifiers that maintain a DC bias voltage of
+0.250 volts on each of its inputs. Because the PA3325-WB-0808 is configured on the SIB864 as a common anode type,
the current polarity to the PhotoniQ preamplifiers is out of the inputs. For this reason, the Input Polarity under the Data Configuration menu in the PhotoniQ GUI should be set to positive. See the PhotoniQ user’s manual for more details. The
figure below shows a typical SIB864 display of random particle signals on the 8 x 8 SIPM array.
Figure 4: PhotoniQ IQSP582 Graphical User Interface
The 64 SIPM channels from the PA3325-WB-0808 are labeled in Ketek’s datasheet as channels A1 through H8. These
channels map to Vertilon’s PhotoniQ data acquisition system channels according to the table below.
Ketek SIPM Array Channel Number Vertilon DAQ Channel Number
A1, A2, …, A8 1, 2, …, 8
B1, B2, …, B8 9, 10, …, 16
C1, C2, …, C8 17, 18, …, 24
D1, D2, …, D8 25, 26, …, 32
E1, E2, …, E8 33, 34, …, 40
F1, F2, …, F8 41, 42, …, 48
G1, G2, …, G8 49, 50, …, 56
H1, H2, …, H8 57, 58, …, 64
Table 2: SIPM Array Channel Mapping
High Voltage Interface
The SIB864 employs the interface circuit shown below between the high voltage input connector, J7, and the common
anodes of the SiPM array. The monitor output (HVMON) allows the high voltage anode bias to the SIPMs to be indirectly
monitored at a reduced voltage level. Voltage readings at the monitor point should be scaled by a factor of 21. Calibration
of the scale factor may be required for very accurate measurements.
Warning: The high voltage section of the SIB864 contains signals at voltage levels
that can exceed negative 100 volts. Never touch a component or signal in this area.
The anodes from each SIPM device in the array are bussed together and connected to the input of a single currentsensitive preamplifier on the SIB864. The preamplifier generates a voltage signal in response to the current signal on its
input from any of the 64 SIPMs in the array. This voltage signal is available on an SMB output connector on the SIB864
and is also fed to the input of the discriminator. There are three settings for the preamplifier gain — low, medium, and
high — which are selected through the SIB864 configuration dialog box in the PhotoniQ graphical user interface shown
below.
The discriminator generates a logic signal when a pulse from the preamplifier exceeds a user-defined threshold. The
SIB864 GUI dialog box allows the user to set this threshold between 0 and 50% where 50% is equal to one half of the
maximum possible signal amplitude in the discriminator channel. When a pulse is detected, the trigger output from the
board becomes active. The polarity can be set to either positive or negative.
Figure 7 shows the operation of the leading edge discriminator. A positive-going current pulse into the preamplifier results
in a negative-going pulse on its output. This pulse is compared to a threshold that is adjusted using the SIB864
configuration dialog box in the PhotoniQ GUI. A logic high (for positive polarity control) is generated after a small delay
(td) from when the pulse first crosses the threshold, Vth. The discriminator switches back to a logic low when the pulse
crosses the threshold from the opposite direction as it returns back to the baseline level.
INPUT
CURRENT
V
PREAMP
OUTPUT
THRESHOLD
POINT
DISCRIMINATOR
OUTPUT
th
TRIGGER
t
d
POINT
Figure 7: Leading Edge Discriminator Timing
An additional feature of the discriminator is a status LED that can be selectively enabled and disabled in the SIB864 GUI
dialog box. Under normal triggering conditions, this LED blinks green when and event is detected, and is off when no
event is detected. The LED blinks red if the user sets the discriminator threshold to a value below the discriminator
channel’s baseline level.
Temperature Sensor
An on-board temperature sensor is located on the bottom side of the SIB864 near the SiPM array. The sensor reports the
temperature of the circuit board in degrees Celsius to the PhotoniQ graphical user interface. This information is useful for
determining the proper bias to the SiPM array. Temperature data is not logged to a file by the PhotoniQ data acquisition
system.
The SIB864 connectors and cables are fully compatible with all Vertilon PhotoniQ systems. For applications utilizing data
acquisition systems other than Vertilon’s PhotoniQ series, the pinouts for connectors J1 and J2 are provided in Table 6 as
a reference.
r alteration of data, delays, lost profits or savings, arising from the use of this document or the
ingements of patents or other rights
Vertilon Corporation has made every attempt to ensure that the information in this document is accurate and complete. Vertilon assumes no liabilit
consequential, indirect, or special damages including, without limitation, loss of use, loss o
product which it accompanies. Vertilon reserves the right to change this product without prior notice. No responsibility is assumed by Vertilon for any infr
of third parties which may result from its use. No license is granted by implication or otherwise under the patent and proprietary information rights of Vertilon Corporation.