DP83907VF National Semiconductor, DP83907VF Datasheet - Page 18

• Manufacturer Part Number: DP83907VF
• Description: IC CONTROLLR AT/LANII TP 160PQFP
• Manufacturer: National Semiconductor

Specifications of DP83907VF

• Controller Type: Network Interface Controller (NIC)
• Interface: Twisted Pair
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 150mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 160-MQFP, 160-PQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *DP83907VF

4 0 Functional Description
Transmitter
The transmitter consists of four signals the true and compli-
ment Manchester encoded data (TXO
delayed by 50 ns (TXOd
These four signals are resistively combined TXO
TXOd
pre-emphasis and is required to compensate for the twisted
pair cable which acts like a low pass filter causing greater
attenuation to the 10 MHz (50 ns) pulses of the Manchester
encoded waveform than the 5 MHz (100 ns) pulses
An example of how these signals are combined is shown in
the following diagram
b
and TXO
b
FIGURE 16a Circuitry to Connect DP83907 to Twisted Pair Cable with External Filter
with TXOd
g
)
a
This is known as digital
g
) and these signals
(Continued)
a
with
18
The signal with pre-emphasis shown above is generated by
resistively combining TXO
with its compliment is passed to the transmit filter
FIGURE 15 Typical Summed Transmit Waveform
a
and TXOd
TL F 12082 – 11
b
This signal along
TL F 12082 – 10