DC1765A is the demonstration circuit for the LTC®6957-1/ LTC6957-2. It is a low phase noise, dual LVPECL or LVDS output buffer/driver/logic converter. The DC1765A provides 0.5-inch spaced SMA connectors for the differential inputs and outputs. The inputs are terminated to on-board 50-ohm resistors. The LVPECL outputs of the DC1765A-A are individually biased through 130-ohm resistors to ground and then AC-coupled. The transmission lines are 50-ohm, making the outputs suitable to drive 50-ohm input impedance instruments. The LVDS outputs of the DC1765A-B are terminated with 100-ohm differential and are DC-coupled. The DC1765A allows the user to take advantage of the shutdown and bandwidth selection features of the LTC6957. The DC1765A can operate with a single-ended or differential sine wave or square-wave input signal. Supply the DC1765A with 3.3V and it is ready to function. The DC1765A offers extra component population options to make it compatible with different logic signal types. Design files for this circuit board are available at http://www.linear.com/demo.
This document provides instructions for operating the DC1765A demonstration circuit, which features the LTC6957-1/LTC6957-2 low phase noise buffer/driver/logic converter. It includes setup procedures, configuration options, and component details for both LVPECL and LVDS output versions. The circuit is designed for engineering evaluation and not for commercial use, with specific safety and liability disclaimers included.
| Output Type | LVPECL or LVDS |
|---|---|
| Supply Voltage | 3.3V |
| Input Signal Type | Single-ended or differential sine wave or square-wave |
Supply the DC1765A with 3.3V and it is ready to function.
Configure the input bandwidth of the LTC6957 with the use of FIL TA (JP1) and FIL TB (JP2) jumpers.
The DC1765A-A is for LVPECL output and the DC1765A-B is for LVDS output.