ASIC Example Project: Quad CMOS Low-Noise Charge Sensitive Preamplifier
F-CSA104 contains 4 channels of charge sensitive preamplifiers with differential line
drivers. It has particularly been designed for the use with
semiconductor radiation detectors operating with liquid nitrogen as coolant
(T = 77K/-196°C).
F-CSA104 joins the
formerly discrete input FET with the preamplifier in a single IC,
thus forming the next step of integration for better immunity
to interference. F-CSA104's noise
performance has been optimized for use with capacitive detectors
of 0 - 100pF; flicker noise is reduced by use of a p-channel
MOSFET as input transistor. In cases where noise matching to
higher capacitance detectors is vital, an external p-channel FET
may be connected to the IC.
A range of F-CSA104's parameters (including
offset and preamplifier decay constant) can be programmed via an I2C
interface. F-CSA104's linearity and offset have been designed
for use with 14 bit ADC systems, thus being ideally suited for
spectroscopy applications.
The high current
drive differential line drivers allow for directly driving a 100
Ohm twisted pair cable.
Features
- Very low noise (ENC=220e- @ Cdet = 30pF, T=27°,
Tpeak = 20µs)
- Temperature
range -200°C ... +50°C
- Fast
differential outputs (trise < 30 ns)
- Gain
5.84 mV/fC, 316 mV/MeV(Ge),
258mV/MeV(Si)
- Input
signal range ± 600 fC, ±
11MeV(Ge), ± 13MeV(Si)
- 14
bit linearity for spectroscopy applications
- Adjustable
preamplifier time constant 1us ... 1.5ms
- Optional
connection of external p-channel FET
- Optimized for
detectors of 0 pF ... 100 pF
- All
stages DC coupled, triple offset suppression
- I2C-interface for
parameter adjustment
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Block diagram