USB 3.0 Cable
90-MHz
Bandpass
Filter
Power
Switch
Low-Noise
Power Supply
+5 VDC @ 3 A
TSW14J56EVM
Mini-USB Cable
PC Running
HSDC Pro
+5 VDC Power Supply Cable
Low-Noise
Power Supply
+5 VDC @ 3 A
+15 dBM
Analog Input
Low-Noise
Signal Generator
90 MHz, +15 dBm
Jumpers
JP3 Short 2-3
JP7 Short 2-3
JP2 Open
JP21/22/23/24 Open
Remove C47, C48
Place R35, R39 With 0.1 µF
Bandpass
Filter
CLK Input
Low-Noise
Signal Generator
Power
Splitter
ADC EVM
Optimizing Evaluation Results
12
SBAU290 – September 2017
Copyright © 2017, Texas Instruments Incorporated
ADS54J64 Evaluation Module
shows the test setup using an external device clock source.
Figure 6. Test Setup Using an External Device Clock Source
3.4
Using a Coherent Input Source Frequency
A rectangular window function can be applied to the captured data when the sample rate and the input
frequency are set precisely to capture an integer number of cycles of the input frequency (sometimes
called coherent frequency). Coherent input and sampling frequencies may yield better SNR results. The
clock and analog inputs must be frequency locked (such as through 10-MHz references) to achieve
coherency.
