Sundance SMT784 - Manual (Page 14)

User Manual SMT784 Page 14 of 31 Last Edited: 19/03/2009 14:12:00
5.12 Clock Distribution
There is one integrated clock generator on the mezzanine module (AD9510 – Analog
Devices). The user can either use this clock (on-board) or provide the module with
an external clock (input via MMCX connector).
ADCs can all receive the same clock or the integer multiple of it (x2, x3……x32), the
maximum being 125MHz for each ADC. This clock can be coming from the on-
board VCXO or from an external source.
An extra connector outputs the reference clock for multiple-module systems.
Figure 4 Clock Distribution
The main characteristics of the mezzanine clocks are as follows:
External Reference Input
Input Voltage Level 0.5 – 3.3 Volts peak-to-peak (AC-coupled)
Input Impedance 50-Ohm (Termination implemented at the connector)
Frequency Range 0 – 100 MHz.
External Reference Output
Output Voltage Level 1.6 Volts peak-to-peak (AC-coupled)
Output Impedance 50-Ohm (Termination implemented at the connector)
External Sampling Clock Input
Input Voltage Level 0.5 – 3.3 Volts peak-to-peak (AC-coupled)
Format Single-ended or differential on option (3.3V LVPECL).
Frequency range 10-125 MHz
External Sampling Clock Output
Output Voltage Level 0-2.4 Volts fixed amplitude.
Output Format LVTTL