1.2 Channel input specifications
10
Acqiris SA230E User's Manual
1.2 Channel input specifications
This section provides information and specifications regarding the input characteristics of the ADC
module.
The SA230E provides one 14-bit DC-coupled channel at the sampling rate of 4 GS/s.
Channel input
The SA230E has the following front end capabilities:
Coupling / Impedance
Full Scale Ranges (FSR)
Maximum operating voltage
Input voltage offset
DC / 50 Ω
500 mV
± 600 mVpk
± FSR/2
2.5 V
± 3 Vpk
± FSR/2
Table 1.2
- Channel input specifications.
It is also possible to optimize the calibration for a specified target voltage. For details, see
Calibration optimized for a target voltage (page 77)
.
Impedance & coupling
The input channel termination is 50 Ω. The input coupling is DC.
Input protection
The input amplifiers are designed to accept signals within the absolute maximum operating voltages
shown in the table.
Bandwidth and rise time
The bandwidth specification indicates the frequency at which an input signal will be attenuated by 3 dB
(approximately 30% loss of amplitude).
The bandwidth of the SA230E is from DC to 2 GHz
(typical)
.
The bandwidth also has an impact on the minimum rise and fall times that can be passed through the
front-end electronics. A pulse with a very sharp edge will be observed to have a minimum rise time
T
min
determined by the front-end electronics. In general a pulse with a given 10-90% rise time
T
10-
90real
will be observed with a lower value given by:
T
10-90
2
=
T
10-90real
2
+
T
min
2
where T
min
(ns) ≈ 0.35/
BW
(GHz).
