SIB332B APD Interface Board S8550 Series
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Vertilon Corporation, 66 Tadmuck Road, Westford, MA 01886
/
Tel: (978) 692-7070
/
Fax: (978) 692-7010
/
www.vertilon.com
APD Array Anode Circuits
The 32 anode signals (AN1 – AN32) from the S8550 APD array are DC-coupled on the SIB332B to a specialized
connector (J1) referred to as the sensor interface board (SIB) connector. The SIB connector mates to a proprietary low-
noise, high density SIB cable assembly that carries the 32 anode signals on coaxial connections to a Vertilon PhotoniQ
32 channel charge integrating data acquisition system. Depending on the required speed and dynamic range, either a
PhotoniQ IQSP480 high dynamic range system or an IQSP580 high speed system can be used as the main data
acquisition unit. Figure 4 below illustrates the equivalent circuit as seen by each APD array anode. Each detector anode
is coupled to its respective transimpedance amplifier in the PhotoniQ through a 50 ohm resistor. With the common
cathode of the array supplying the high voltage bias, the negative to each detector is applied through the 50 ohm
resistors from the connection to the PhotoniQ. This voltage will normally be about +2.5V. Note, because the Hamamatsu
S8550 APD array is of the common cathode type, the current polarity to the PhotoniQ preamplifiers is
into
its inputs. For
this reason, the
Input Polarity
under the
Data Configuration
menu in the PhotoniQ GUI should be set to
negative
. See the
PhotoniQ user’s manual for more details.
Figure 4: APD Array Anode Circuits
Summary of Contents for SIB332B
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