EMI7204MU, EMI7206MU, EMI7208MU

http://onsemi.com

4

Table 2. FREQUENCY CHART

Bandwidth

Maximum

Supported

Frequency

Third

Harmonic

Frequency

3 dB − 100 MHz

100 MHz

6 dB − 200 MHz

200 MHz

9 dB − 300 MHz

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

Figure 5. Input and Output Waveforms of Filter

Input Waveform

Output Waveform

Input Waveform

Output Waveform

ORDERING INFORMATION

Device

Package

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.