1055478-1 TE Connectivity, 1055478-1 Datasheet - Page 116

• Manufacturer Part Number: 1055478-1
• Description: Connector Accessories Cable Bender
• Manufacturer: TE Connectivity
• Type: Benderr

Specifications of 1055478-1

• Lead Free Status / RoHS Status: RoHS Not Applicable

7116
Catalog 1308940
Revised 5-03
www.tycoelectronics.com
Pulses
The sine wave is most often used for communication
purposes where intelligence is imposed on the wave by a
variation in amplitude (amplitude modulation, AM) or by a
variation in frequency (frequency modulation, FM).
Pulses, on the other hand, are primarily used in computers
and digital instrumentation. Since pulses are generally used
for triggering purposes, the pulse rise/fall time, amplitude
and width are the most important. Figure 10 shows a pulse
and identifies these characteristics.
1000
Inches
100
0.1
10
1
TFE
Polyethylene
Nylon
TPX
Polypropylene
Acetal
.001
_________
Dielectric
Material
GHz
.01
Properties of Insulating Materials
Repetition
Rate
GHz
Pulse Characteristics
TEFLON (E=2.03)
FREQUENCY (MHZ)
Dimensions are in inches and
millimeters unless otherwise
specified. Values in brackets
are metric equivalents.
.1
_________
Dielectric
Constant
Frequency (MHZ)
GHz
Figure 10
Figure 9
2.03
2.3
4.6-4.0
2.12
2.25
3.7
10%
Table 1.
90%
RF Connectors
Appendix A - Theory and Application
1
GHz
Rise
Time
__________________
Temperature Range
AIR (E=1.00)
90%
Width
10%
Operating
-70 +250°C
-60 +80°C
-40 +120°C
-65 +85°C
-40 +105°C
-65 +85°C
Fall Time
10
GHz
Amplitude
Dimensions are shown for
reference purposes only.
Specifications subject
to change.
100
GHz
Notice that rise time is the time required for the pulse to rise
from 10% to 90% of its amplitude — not from zero to maxi-
mum. Rise and fall time is perhaps the single most impor-
tant characteristic of a pulse in today’s high-speed digital
equipment. Figure 11 shows that the faster the rise and fall
time, the more pulses will fit in a given time frame.
The bit rate for a system is the maximum rate of pulses per
second that a system can process without causing data
errors. The maximum performance can also be specified in
terms of baud rate. The baud rate is defined as the number
of characters (bytes) that are transmitted per second.
Generally a character represents 10 bits (7 bits for the infor-
mation, one parity bit, and two for start and stop, totalling 10).
Now that we know why fast pulses are required, the next
problem is how to obtain faster rise times. A pulse is made
up of a great number of different frequencies, and the more
high frequencies a pulse contains, the faster will be its rise
time and the flatter will be its peak. To better understand
this, refer to Figure 12. At A, you will see a fundamental fre-
quency (1), its third harmonic (3), and the resultant wave-
form (S3), which is a combination of 1 and 3. Although this
does not yet resemble a square wave, you will note that the
rise time is decreased, and a dip appears at the peak. At
B of Figure 12, we have added the fifth harmonic. Rise
time is further decreased, and the peak is beginning to flat-
ten out. At C the seventh harmonic has been included, and
the resultant wave S7 begins to resemble a square wave.
As more high frequency harmonics are added to the wave-
form, it will more closely resemble a square wave, and the
squarer it becomes, the faster will be the rise time.
(Continued)
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C. America: 52-55-5-729-0425
Pulse Rise and Fall Time
Figure 11
Time
Time
A
B
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