Embedded Systems Conference
Breaking News
Comments
Sanjib.A
User Rank
Author
Testing Ethernet Compliance
Sanjib.A   3/30/2014 3:36:18 AM
NO RATINGS

While reading this article, a question just occurred to me, which I came across a few days back and I did not know the answer. To implement Fast Ethernet or Giga-bit Ethernet, we generally use the off-the-shelf processors with in-built MAC, 0ff-the-shelf PHY chips compliant to the Ethernet standard and magnetics, connectors per standard. What are the test cases which need to be done to check whether Ethernet implemented actually complied to the respective standards?

MeasurementBlues
User Rank
Author
Re: Testing Ethernet Compliance
MeasurementBlues   4/1/2014 8:28:54 AM
NO RATINGS
Sanjib,

In this case, the formatting of the bits into packets don;t matter. Speed experiments are done using a PRBS pattern to assure an almost random set of bits. The point is to prove that data rates are possible. What those bits represent is irrelevant here.

zeeglen
User Rank
Author
Multimode?
zeeglen   3/30/2014 10:54:00 AM
NO RATINGS
Since the 850 nm multimode fiber lengths have such significance in the test results, wonder what would the maximum lengths be using singlemode fiber at 1310 nm?

DKuchta
User Rank
Author
Re: Multimode?
DKuchta   3/31/2014 2:47:32 PM
NO RATINGS
Is your question about fiber properties or VCSEL poperties?

In general, 1310nm VCSELs have lower ouput power and, to date, much lower modulation speeds than 850nm devices.  In the literature, 30Gb/s over 10km of single mode fiber has been demonstrated from a 1270nm (~1310nm) VCSEL.

For 1310nm VCSELs, the single mode fiber distance will be in the 10km range, limited by either the available optical power or the spectral width.

zeeglen
User Rank
Author
Re: Multimode?
zeeglen   3/31/2014 7:41:33 PM
NO RATINGS
@ DKuchta In general, 1310nm VCSELs have lower ouput power and, to date, much lower modulation speeds than 850nm devices.


Thanks, this answers my question.  Was thinking of an external modulator rather than laser keying.  Amazing that VCSELs can be directly keyed at this rate!


 



Radio
NEXT UPCOMING BROADCAST
In conjunction with unveiling of EE Times’ Silicon 60 list, journalist & Silicon 60 researcher Peter Clarke hosts a conversation on startups in the electronics industry. One of Silicon Valley's great contributions to the world has been the demonstration of how the application of entrepreneurship and venture capital to electronics and semiconductor hardware can create wealth with developments in semiconductors, displays, design automation, MEMS and across the breadth of hardware developments. But in recent years concerns have been raised that traditional venture capital has turned its back on hardware-related startups in favor of software and Internet applications and services. Panelists from incubators join Peter Clarke in debate.
Most Recent Comments
Flash Poll
Top Comments of the Week
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Special Video Section
The LT®3042 is a high performance low dropout linear ...
Chwan-Jye Foo (C.J Foo), product marketing manager for ...
The LT®3752/LT3752-1 are current mode PWM controllers ...
LED lighting is an important feature in today’s and future ...
Active balancing of series connected battery stacks exists ...
After a four-year absence, Infineon returns to Mobile World ...
A laptop’s 65-watt adapter can be made 6 times smaller and ...
An industry network should have device and data security at ...
The LTC2975 is a four-channel PMBus Power System Manager ...
In this video, a new high speed CMOS output comparator ...
The LT8640 is a 42V, 5A synchronous step-down regulator ...
The LTC2000 high-speed DAC has low noise and excellent ...
How do you protect the load and ensure output continues to ...
General-purpose DACs have applications in instrumentation, ...
Linear Technology demonstrates its latest measurement ...
10:29
Demos from Maxim Integrated at Electronica 2014 show ...
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
STMicroelectronics demoed this simple gesture control ...
Keysight shows you what signals lurk in real-time at 510MHz ...
TE Connectivity's clear-plastic, full-size model car shows ...