DC1765A-A Analog Devices

DEMO MANUAL DC1765A LTC6957-1/LTC6957-2 Low Phase Noise, Dual LVPECL or LVDS Output Buffer/Driver/Logic Converter Description Demonstration Circuit 1765A features the LTC 6957-1/ and are DC-coupled. The DC1765A allows the user to LTC6957-2, a low phase noise, dual LVPECL or LVDS take advantage of the shutdown and bandwidth selection output buffer/driver/logic converter. features of the LTC6957. The DC1765A can operate with a single-ended or differential sine wave or square-wave The DC1765A provides 0.5 spaced SMA connectors for input signal. Supply the DC1765A with 3.3V and it is the differential inputs and outputs. The inputs are termi- ready to function. The DC1765A offers extra component nated to on-board 50 resistors. The LVPECL outputs population options to make it compatible with different of the DC1765A-A are individually biased through 130 logic signal types. resistors to ground and then AC-coupled. The transmis- sion lines are 50, making the outputs suitable to drive Design files for this circuit board are available at 50 input impedance instruments. The LVDS outputs DEMO MANUAL DC1765A Quick s Dp The DC1765A is very straightforward to operate. Refer to DC1765A Reconfiguration Figure 1 for the following discussion. The DC1765A is flexible and allows the connectivity of a variety of input and output signal types. The DC1765A is DC1765A Configuration configured as shown in the schematic diagram. However, 1. Apply a low-noise and low-spurious 3.3V supply between the DC1765A allows the installation of different input and the V+ (E1) and GND (E2) turrets. output configurations to adapt to a variety of logic sig- nals. Refer to the Applications Information section of the 2. Connect a low phase-noise (or jitter) single-ended or LTC6957 data sheet for all possible connectivity options differential input signal to IN+ (J1) and/or IN (J2) that can be implemented by modifying the DC1765A. SMA connectors. Refer to the LTC6957 data sheet for appropriate input signal types and levels. 3. Connect either of the outputs (OUT1, J3 and J4 or OUT2, J5 and J6) to a high-speed scope, spectrum analyzer or a signal analyzer to start the evaluation of the LTC6957. 4. Configure the input bandwidth of the LTC6957 with the use of FILTA (JP1) and FILTB (JP2) jumpers. Follow the instructions given in the LTC6957 data sheet to choose the correct bandwidth given an input signal. 5. Shut down an unused output by using jumper SD1 (JP3) to shutdown OUT1 or jumper SD2 (JP4) to shutdown OUT2. dc1765af 2 ure roce tart