Spec issue on MSE leakage current in SPI-3

Aloisi, Paul aloisi at unitrode.com
Fri Apr 30 10:08:38 PDT 1999


* From the T10 Reflector (t10 at symbios.com), posted by:
* "Aloisi, Paul" <aloisi at unitrode.com>
*
John, Bill,

I think the email things have gone well beyond what John is asking.

John was asking for relief on the Leakage - 20 micro amps when the signal is
above VCC.
We changed from Vcc to 4.1 volts because we have supply voltages from 2.5 to
5 volts on the SCSI controllers. We also have a high impedance requirement
even when Vcc is 0 volts, device powered down.

The SCSI signals would be fine if we spec 20 micro amps up to 3 volts and 1
mA up to 4.1 volts. I would not like to see the bus clamped, because some of
the old active negation drivers drove over 4 volts. 

John - is the above statement OK or do you need higher current above 3
volts?

Thank you,
Paul


-----Original Message-----
From: John Lohmeyer [mailto:lohmeyer at ix.netcom.com]
Sent: Thursday, April 29, 1999 1:01 PM
To: ALOISI at MSMAILGW.UICC.COM
Subject: Spec issue on MSE leakage current in SPI-3


* From the T10 Reflector (t10 at symbios.com), posted by:
* John Lohmeyer <lohmeyer at ix.netcom.com>
*
One of our circuit designers has noticed that the leakage current spec for
MSE in SPI-3 (Table 16 on page 50) says that the 20 uA maximum leakage
applies from local ground to 4.1 V.  In SPI-2 rev 14 this specification was
over the range of local ground to Vcc.  Does anyone remember why this upper
parameter was changed from Vcc to 4.1 V?  We would like to change this spec
range back to local ground to Vcc in SPI-3.

John


--
John Lohmeyer                  Email: lohmeyer at ix.netcom.com
LSI Logic Corp.                Voice: +1-719-533-7560
4420 ArrowsWest Dr.              Fax: +1-719-533-7036
Colo Spgs, CO 80907              BBS: +1-719-533-7950

*
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at symbios.com
*
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at symbios.com





More information about the T10 mailing list