DP83848J_07 NSC [National Semiconductor], DP83848J_07 Datasheet - Page 28
![no-image](/images/no-image-200.jpg)
DP83848J_07
Manufacturer Part Number
DP83848J_07
Description
Manufacturer
NSC [National Semiconductor]
Datasheet
1.DP83848J_07.pdf
(78 pages)
- Current page: 28 of 78
- Download datasheet (2Mb)
www.national.com
4.2.2.2 Base Line Wander Compensation
The DP83848J is completely ANSI TP-PMD compliant
and includes Base Line Wander (BLW) compensation.
The BLW compensation block can successfully recover
the TP-PMD defined “killer” pattern.
BLW can generally be defined as the change in the aver-
age DC content, relatively short period over time, of an AC
coupled digital transmission over a given transmission
medium. (i.e., copper wire).
BLW results from the interaction between the low fre-
quency components of a transmitted bit stream and the
frequency response of the AC coupling component(s)
within the transmission system. If the low frequency con-
tent of the digital bit stream goes below the low frequency
pole of the AC coupling transformers then the droop char-
acteristics of the transformers will dominate resulting in
potentially serious BLW.
The digital oscilloscope plot provided in Figure 9 illus-
trates the severity of the BLW event that can theoretically
be generated during 100BASE-TX packet transmission.
This event consists of approximately 800 mV of DC offset
for a period of 120 µs. Left uncompensated, events such
as this can cause packet loss.
4.2.3 Signal Detect
The signal detect function of the DP83848J is incorpo-
rated to meet the specifications mandated by the ANSI
FDDI TP-PMD Standard as well as the IEEE 802.3
100BASE-TX Standard for both voltage thresholds and
timing parameters.
Note that the reception of normal 10BASE-T link pulses
and fast link pulses per IEEE 802.3u Auto-Negotiation by
the 100BASE-TX receiver do not cause the DP83848J to
assert signal detect.
Figure 9. 100BASE-TX BLW Event
28
4.2.4 MLT-3 to NRZI Decoder
The DP83848J decodes the MLT-3 information from the
Digital Adaptive Equalizer block to binary NRZI data.
4.2.5 NRZI to NRZ
In a typical application, the NRZI to NRZ decoder is
required in order to present NRZ formatted data to the
descrambler.
4.2.6 Serial to Parallel
The 100BASE-TX receiver includes a Serial to Parallel
converter which supplies 5-bit wide data symbols to the
PCS Rx state machine.
Related parts for DP83848J_07
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![SFTB](/images/no-image3.png)
Part Number:
Description:
Thin SOT23 1A Load Step-Down DC-DC Regulator
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS3603N](/images/no-image3.png)
Part Number:
Description:
TRI-STATE Dual Receiver
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS36149N](/images/no-image3.png)
Part Number:
Description:
Hex MOS Drivers
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS3654N](/images/no-image3.png)
Part Number:
Description:
Printer Solenoid Driver
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS3669N](/images/no-image3.png)
Part Number:
Description:
Quad High Current Peripheral Driver
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS3691N](/images/no-image3.png)
Part Number:
Description:
(RS-422/RS-423) Line Drivers with TRI-STATE Outputs
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS3695TJ](/images/no-image3.png)
Part Number:
Description:
Multipoint RS485/RS422 Transceivers/Repeaters
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS36C279TM](/images/no-image3.png)
Part Number:
Description:
Low Power EIA-RS-485 Transceiver with Sleep Mode
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS3884AVF](/images/no-image3.png)
Part Number:
Description:
BTL Handshake Transceiver
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![MM5034N](/images/no-image3.png)
Part Number:
Description:
Octal 80-Bit Static Shift Register
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![MM53143J](/images/no-image3.png)
Part Number:
Description:
PUSH BUTTON PULSE DIALER CIRCUITS
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![MM54C914J](/images/no-image3.png)
Part Number:
Description:
Hex Schmitt Trigger with Extended Input Voltage
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![MM58167](/images/no-image3.png)
Part Number:
Description:
Microprocessor Real Time Clock
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS75108M](/images/no-image3.png)
Part Number:
Description:
Dual Line Receivers
Manufacturer:
NSC [National Semiconductor]
Datasheet:
![DS75113M](/images/no-image3.png)
Part Number:
Description:
Dual TRI-STATE Differential Line Driver
Manufacturer:
NSC [National Semiconductor]
Datasheet: