Table of Contents
Advertisement
Selecting the SCLK
Source and
Reference
Figure 3-13, Modifying the SCLK and 10 MHz Clock Source
Generating Standard
Waveforms
In cases where synchronization to other instruments in a system is
needed, you have two options: Use an external clock source for the
10 MHz reference clock or replace the internal sample clock
generator entirely with an external clock source. Either way, this is a
major twist in the 2074 basic operation because if, for any reason,
you leave one or both source options on external and do not apply
the necessary signal to the input, the operation of the generator will
be impeded without visual references that something is wrong.
The SCLK and the 10MHz reference source menu were placed in
the Customize menu, as shown in Figure 3-13. Change these
settings only if you are absolutely sure that another reference
source is available at the appropriate inputs.
The SCLK input is located on the rear panel. Use this input to
replace the internal sample clock generator. The external sample
clock input accepts ECL level signals, terminated to –2V into 50Ω.
The 10 MHz reference input is also located on the rear panel. It
accepts TTL level signals only. Note that the 2074 internal
reference is accurate to within 1 ppm.
To display and modify the SCLK or the 10 MHz clock source, press
TOP, then Utility and scroll down to the Customize option.
The majority of applications require the use of common waveforms
such as sinusoidal, triangular and square. In fact, these are the only
waveforms that function generators can produce and therefore, one
should expect that these waveforms be available even in a complex
generator such as this. The 2074, being a completely digital
instrument, has a library of built-in waveforms that allow generation
of these basic waveforms plus many more.
By default, the 2074 is programmed to generate one of the common
Using the Instrument
Selecting the SCLK Source and Reference
3
3-25
Advertisement
Table of Contents
