Acqiris SA220P - Channel Input Specifications

1.2 Channel input specifications
10 Acqiris SA220P User's Manual
1.2 Channel input specifications
This section provides information and specifications regarding the input characteristics of the ADC
card.
The SA220P provides two 14-bit DC-coupled channels at the sampling rate of up to 2 GS/s.
Channel input
The SA220P 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.
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 SA220P is from DC to 1.2 GHz (typical) with a sampling rate of 2 GS/s.
The 1 GS/s version (LSR/LBW options) has a bandwidth from DC to 475 MHz (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).