[802.3af] RE: Max classification time for PD spec
Yair,
My PD and PSE can easily meet the new specification.
I agree that this is a good item to add into the spec.
Thong Huynh
Thong Huynh
Senior Corporate Applications Engineer
Maxim Integrated Products
120 San Gabriel Dr. M/S 140-3
Sunnyvale, CA. 94086
Phone: 408-530-6375
Fax: 408-222-1737
Email: thong_huynh@xxxxxxxxxxx
> -----Original Message-----
> From: Dave Dwelley [SMTP:ddwelley@xxxxxxxxxx]
> Sent: Monday, August 12, 2002 9:54 AM
> To: Yair Darshan; Thong Huynh (E-mail); 'Hemmah, Steve'
> Cc: 'stds-802-3-pwrviamdi@xxxxxxxx'
> Subject: Re: Max classification time for PD spec
>
> Yair -
>
> Good catch. This is something we need to spec.
>
> All circuits LTC has in development will be OK with the new specs. I'd
> guess nearly any integrated solution will be able to meet the 5ms number
> without trouble.
>
> Dave
>
> At 03:54 PM 8/12/2002 +0200, Yair Darshan wrote:
> >Guys,
> >
> >We have specified min and max classification time for the PSE spec.
> >It means that the PSE will sense the current or voltage after 10ms from
> >the time that the Voltage or current to the PSE port and the whole
> >function will be ended after total of 75ms.
> >
> >The reason for 10ms min was to allow the PD enough time to get stable.
> >
> >Now we have to limit the max stabilization time of the circuits at the PD
>
> >to keep our 6db margin.
> >
> >So I suggest to define at the PD spec at table 33-13 as follows:
> >
> >Add item 7 to the table. Parameter: "PD classification stability time " ,
>
> >Unit:"ms", value: 5ms max.
> >Add note for item 7: "Measured from the time that classification voltage
> >or current applied to the PD port until the voltage or current reached to
>
> >their 1% of their steady state value"
> >
> >Summary:
> >
> >The classification circuits at the PD will be stable within 5ms max.
> >The PSE will start to take data after 10ms min. and will remove
> >classification voltage/current within 75ms max.
> >
> >Please check (PD chip vendors) if you can meet those numbers or suggest
> >modifying it.
> >
> >Regards
> >
> >Yair
> >
> >
> >Darshan Yair
> >Chief Engineer
> >PowerDsine Ltd. - Powering Converged Networks
> >1 Hanagar St., P.O. Box 7220
> >Neve Ne'eman Industrial Zone
> >Hod Hasharon 45421, Israel
> >Tel: +972-9-775-5100, Cell: +972-54-893019
> >Fax: +972- 7755150-09
> >E-mail: <<mailto:yaird@xxxxxxxxxxxxxx>mailto:yaird@xxxxxxxxxxxxxx>.
> ><http://www.powerdsine.com>
> >
>