ELM304
Example Application (continued)
Note: There is no colourburst on
the ‘back porch’, so this is
a monochrome signal
Figure 2. Gray bar pattern output
V1
V2
V3
Figure 3. ELM304 outputs to give gray bars
connections, and an adequate amount of power supply
filtering. Since this circuit switches voltages quite
rapidly, and it is of relatively low impedance, it will tend
to radiate rf signals. To reduce any effects, you should
keep your connections short, and possibly consider a
shielded enclosure.
used, along with quality connectors, shorter supply
leads, and more power supply filtering.
Figure 3 should actually be considered to be an
extension of Figure 2. The dotted lines represent the
transition points in the signal displayed in Figure 2, so
that you can see how the three ELM304 output
voltages combine to make one signal. We are often
asked how the signals work, and this is meant to show
that. If you are testing your circuit and look at this
same waveform, don’t forget that the levels shown are
for with a 75W load (so you may have to add one). If
Figure 2 shows an actual circuit output when
connected to a 5.00V supply, and a 75 W load. Note
that the slight noise and overshoot may be due to the
experimenter board setup, and would likely be
‘cleaned up’ quite a bit if a proper circuit board were
ELM304DSC
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