DS25BR100TSDX National Semiconductor, DS25BR100TSDX Datasheet - Page 10

• Manufacturer Part Number: DS25BR100TSDX
• Manufacturer: National Semiconductor

Specifications of DS25BR100TSDX

• Number Of Elements: 1
• Input Type: CMOS
• Operating Supply Voltage (typ): 3.3V
• Differential Input High Threshold Voltage: 100mV
• Diff. Input Low Threshold Volt: -100mV
• Output Type: Repeater
• Differential Output Voltage: 450mV
• Transmission Data Rate: 390.625MBps
• Propagation Delay Time: 0.465ns
• Power Dissipation: 2.08W
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Number Of Receivers: 1
• Number Of Drivers: 1
• Lead Free Status / RoHS Status: Not Compliant

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Test Channel Loss Characteristics
The test channel was fabricated with Polyclad PCL-FR-370-
Laminate/PCL-FRP-370 Prepreg materials (Dielectric con-
Device Operation
INPUT INTERFACING
The DS25BR100/101 accepts differential signals and allows
simple AC or DC coupling. With a wide common mode range,
the DS25BR100/101 can be DC-coupled with all common dif-
ferential drivers (i.e. LVPECL, LVDS, CML). The following
three figures illustrate typical DC-coupled interface to com-
mon differential drivers.
The DS25BR100 inputs are internally terminated with a
100Ω resistor for optimal device performance, reduced com-
ponent count, and minimum board space. External input ter-
minations on the DS25BR101 need to be placed as close as
possible to the device inputs to achieve equivalent AC per-
Test Channel
A
B
C
D
E
F
(inches)
Length
10
20
30
15
30
60
Typical LVDS Driver DC-Coupled Interface to DS25BR100 Input
Typical CML Driver DC-Coupled Interface to DS25BR100 Input
500 MHz
-1.2
-2.6
-4.3
-1.6
-3.4
-7.8
750 MHz
-10.3
-1.7
-3.5
-5.7
-2.2
-4.5
10
1000 MHz
stant of 3.7 and Loss Tangent of 0.02). The edge coupled
differential striplines have the following geometries: Trace
Width (W) = 5 mils, Gap (S) = 5 mils, Height (B) = 16 mils.
formance. It is recommended that SMT resistors sized 0402
or smaller be used and the mounting distance to the
DS25BR101 pins kept under 200 mils.
When using the DS25BR101 in a limited multi-drop topology,
any transmission line stubs should be kept very short to min-
imize any negative effects on signal quality. A single termi-
nation resistor or resistor network that matches the differential
line impedance should be used. If DS25BR101 input pairs
from two separate devices are to be connected to a single
differential output, it is recommended that the DS25BR101
devices are mounted directly opposite of each other. One on
top of the PCB and the other directly under the first on the
bottom of the PCB, this keeps the distance between inputs
equal to the PCB thickness.
-12.4
Insertion Loss (dB)
-2.0
-4.1
-7.0
-2.7
-5.6
1250 MHz
-14.5
-2.4
-4.8
-8.2
-3.2
-6.6
20179111
1500 MHz
-16.6
-2.7
-5.5
-9.4
-3.7
-7.7
20179112
1560 MHz
-17.0
-2.8
-5.6
-9.7
-3.8
-7.9