tcm2010-261-4p TDK Corp., tcm2010-261-4p Datasheet - Page 10

• Manufacturer Part Number: tcm2010-261-4p
• Description: Ferrite Chip Common-mode Filters For High-speed Signal Lines,
• Manufacturer: TDK Corp.

Actual measurement example of
USB2.0 differential signal waveform
TCM1005
At the USB2.0's data transmission speed (High speed)
of 480Mbps, repetitive pulse frequency is 240Mhz,
which requires sufficient consideration for effects on
the signal waveform when selecting EMI counter-
measure components to deter the radiation noise
from the cables, etc.
The USB2.0 transmission signal waveforms where no
EMI countermeasure components are attached,
and where TCM1005-900-2P is attached near the
connectors for both HUB and DEVICE are as follows:
Measurement condition
For operational test, the same EMI countermeasure
components are implemented on both the signal
sending and receiving sides, assuming actual use
conditions.
The measurement data below are the results of ob-
servation at a point near TP3 using 0.5m cables. To
observe the characteristic superiority of TCM, the TP2
template, which is more severe than TP3, was used.
Measurement results
Favorable transmission waveforms are achieved with
appropriate CMF(common-mode filter) character-
istic impedance* and low differential-mode imped-
ance.
*
With the USB2.0 standard, the required characteristic impedance
of a common-mode filter is 90 .
Transmission signal waveform
Without EMI preventive components
CMF(common-mode filter) characteristic impedance:
- 0.1
- 0.2
- 0.3
- 0.4
Controller
- 0.5
USB2.0
0.5
0.4
0.3
0.2
0.1
0
IC
0
0.4
DEVICE
Transmission waveform observation point
Eye-pattern diagram
for 0.5m Cable
TP2 template
0.8
TP3
Time (ns)
TCM1005-900-2P
USB Cable (0.5m)
1.2
DATA
1.6
TDK CORPORATION
HUB
2.0
TP2
Applied templates
Transmission signal waveform
With TCM1005-900-2P
Controller
- 0.1
- 0.2
- 0.3
- 0.4
- 0.5
TCM
1005,1210,1608, 2010 type
USB2.0
0.4
0.3
0.2
0.1
0.5
IC
0
0
0.4
9
series
Impedance Analyzer E4991A (Agilent Technologies)
TCM1005-900-2P
Frequency characteristics
Eye-pattern diagram
10000
BACK
1000
1000
100
100
10
10
for 0.5m Cable
1
1
TP2 template
1
1
0.8
NEXT
Time (ns)
10
10
11
1.2
Frequency (MHz)
Common-mode
Impedance
Frequency (MHz)
100
100
1.6
TCM
Differential-mode
Impedance
1000
1000 3000
2.0
10000
10