EMI7204MU, EMI7206MU, EMI7208MU
http://onsemi.com
4
Table 2. FREQUENCY CHART
Bandwidth
Maximum
Supported
Frequency
Third
Harmonic
Frequency
3 dB − 100 MHz 33.33 MHz (f
1
) 100 MHz
6 dB − 200 MHz 66.67 MHz (f
2
) 200 MHz
9 dB − 300 MHz 100 MHz (f
3
) 300 MHz
Considering that 85% of the amplitude of the square is in
the first two terms of the Fourier series approximation most
of the signal content is at the fundamental (maximum
supported) frequency and the third harmonic frequency. If a
signal with a frequency of 33.33 MHz is input to this filter,
the first two terms are sufficiently passed such that the signal
is only mildly affected, as is shown in Figure 5a. If a signal
with a frequency of 66.67 MHz is input to this same filter,
the third harmonic term is significantly attenuated. This
serves to round the signal edges and skew the waveform, as
is shown in Figure 5b. In the case that a 100 MHz signal is
input to this filter, the third harmonic term is attenuated even
further and results in even more rounding of the signal edges
as is shown in Figure 5c. The result is the degradation of the
data being transmitted making the digital data (1’s and 0’s)
more difficult to discern. This does not include effects of
other components such as interconnect and other path losses
which could further serve to degrade the signal integrity.
While some filter products may specify the 6 dB or 9 dB
bandwidths, actually using these to calculate supported
frequencies (and corresponding data rates) results in
significant signal degradation. To ensure the best signal
integrity possible, it is best to use the 3 dB bandwidth to
calculate the achievable data rate.
Input Waveform Output Waveform
a) Frequency = f
1
b) Frequency = f
2
c) Frequency = f
3
Figure 5. Input and Output Waveforms of Filter
Input Waveform Output Waveform
Input Waveform Output Waveform
ORDERING INFORMATION
Device Package Shipping
†
EMI7204MUTAG UDFN8
(Pb−Free)
3000 / Tape & Reel
EMI7206MUTAG UDFN12
(Pb−Free)
3000 / Tape & Reel
EMI7208MUTAG UDFN16
(Pb−Free)
3000 / Tape & Reel
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
