Sundance SMT950 - Manual (Page 13)

Version 2.0 Page 13 of 52 SMT950 User Manual
ADC Channels.
ADC Main Characteristics.
The main characteristics of the SMT950 ADCs are gathered into the following table.
Analogue Inputs
Input voltage range
AC coupled option. 2.4 Vp-p (11.5 dbm –
50 Ohm) Full scale - AC coupled.
DC coupled option. 1.15 Vp-p (Gain
amplifier 6dB) centered around 0. DC
coupled via amplifier. Gain can be adjusted
to a required input amplitude centered
around 0. Minimm gain 6dBs, which should
allow input swing +/-0.575V as full scale.
Impedance
ADC single-ended inputs are to be
connected to a 50
Ω source. Source
impedance matching implemented between
RF transformers and ADC.
Bandwidth ADC bandwidth: 750 MHz.
ADCs Output
Output Data Width 14-Bits
Data Format
2’s Compliment or offset binary
(Changeable via control register)
SFDR 82dBs maximum (manufacturer)
SNR 70dBs maximum (manufacturer)
Minimum Sampling Clock 10 MHz (ADC DLL off)
Maximum Sampling Frequency 125 MHz (ADC DLL on)
Figure 3 - Main features.
ADC Input Stage.
Each ADC Analogue input is AC-coupled via and RF transformer (AC-coupled
version of the SMT950). The 50-Ohm resistor between the connector and the first RF
transformer is not fitted because the source impedance match is implemented
between the second RF transformer and the ADC by the way of two 25-Ohm
resistors.