Fast CR-110 Application Manual

CR-110 charge sensitive preamplifier:
General Description
Cremat's CR-110 is a single channel, low noise charge sensitive
preamplifier intended for use with various types of radiation detectors
including semiconductor detectors, photomultiplier tubes (PMTs),
photodiodes, avalanche photodiodes (APDs), and various gas-based
detectors. The CR-110 is small (less than one square inch in area),
allowing for compact multichannel detection systems to be created
using a modular design. The CR-110 can provide equal performance
with pulses of either polarity.
Detector coupling
The CR-110 can be used either in a direct coupled (DC) mode, or an
AC coupled mode. These configurations are discussed below. If the
detector current exceeds 10 nA, it is recommended that an AC
coupled mode be used to prevent the resulting DC offset of the
preamplifier output from saturating.
10M
Det bias
CR-110
0.01uF
1 2 3 4 5 6 7 8
filtered bias
detector
input
Direct coupled operation
The above figure illustrates a typical configuration in which the CR-110
preamplifier is used to readout a detector in a 'DC coupled'
configuration. Detector current flows directly into the preamplifier input,
which is held at approximately a couple tenths of a volt below ground
potential. Detector current also produces an offset in the preamplifier
output voltage at a rate of 0.2 V per nA. A DC coupled configuration is
recommended unless high detector current causes the DC level at the
output to saturate.
10M
Det bias
0.01uF
200M
1 2 3 4 5 6 7 8
input
0.01uF
detector
Bypassed (AC coupled) operation
In cases in which detector current exceeds approximately
AC coupled configuration is recommended to prevent the DC level of
the output from saturating. The above figure shows the connections
typically made in such a situation.
Package Specifications
The CR-110 circuit is contacted via an 8-pin SIP connection (0.100"
spacing). Leads are 0.020 inches wide. Pin 1 is marked with a white
dot for identification.
0.88"
Cremat, Inc.
0.85"
CR-110
1 2 3 4 5 6 7 8
output
+Vpower
-Vpower
Figure 1.
CR-110
output
+Vpower
-Vpower
Figure 2.
10 nA, an
0.14"
Figure 3.
Equivalent circuit diagram
The figure below shows an simplified equivalent circuit diagram of the CR-110, which is a
two stage amplifier. The first stage is high gain, and the second stage is low gain with an
emphasis on supplying sufficient output current to drive a terminated coaxial cable.. Pin
numbers corresponding with the CR-110 preamplifier are shown. R
(1.4 pF) are the feedback resistor and capacitor respectively.
C f
R f
+
1
G= -20k
Preamplification channels
Equivalent noise charge (ENC)
ENC RMS
Equivalent noise in silicon
Equivalent noise in CdZnTe
ENC slope
Gain
†
Rise time
Decay time constant
Unsaturated output swing
Maximum charge detectable per event
Amplification polarity
Power supply voltage (V )
s
maximum
minimum
Power supply current
Power dissipation
Operating temperature
Output offset
Output impedance
Maximum output current (under load)
Measured with input unconnected, using Gaussian shaping amplifier with time constant =1
*
s. With a detector attached to the input, noise from the detector capacitance, leakage
current, and dielectric losses will add to this figure.
Pulse rise time (defined as the time to attain 90% of maximum value) has a linear
†
relationship with input capacitance. Value cited in the table assumes zero added input
capacitance. To calculate pulse rise time for practical situations, use the equation: t
+ 7 ns, where t is the pulse rise time in ns, and C
r
capacitance) in pF.

application guide

Figure 4.
6
+
8
G=+2
NC 3, 7
5
2, 4 (GND)
o
Assume temp =20 C, V =
s
CR-110
1
*
180
0.03
1.6
2.1
3
1.4
7
140
-6 to +6
7
2.6 x10
4.2
inverting
V = 13
s
V = 6
s
11
see Figure 7
-40 to +85
-0.5 to -0.1
50
70
is the added capacitance (e.g. detector
d
(100 M ) and C
f f
9V, unloaded output
units
electrons
femtoCoul.
keV (FWHM)
keV (FWHM)
elect. RMS /pF
volts /pC
ns
s
volts
electrons
pC
volts
volts
mA
o
C
volts
ohms
mA
=0.4 C
r d