From PICLIST@MITVMA.MIT.EDU Fri Nov 15 07:20:20 2002 Received: from cherry.ease.lsoft.com [209.119.0.109] by dpmail10.doteasy.com with ESMTP (SMTPD32-7.13) id A0B415D9007C; Fri, 15 Nov 2002 07:20:20 -0800 Received: from PEAR.EASE.LSOFT.COM (209.119.0.19) by cherry.ease.lsoft.com (LSMTP for Digital Unix v1.1b) with SMTP id <12.007DC7AE@cherry.ease.lsoft.com>; Fri, 15 Nov 2002 10:06:13 -0500 Received: from MITVMA.MIT.EDU by MITVMA.MIT.EDU (LISTSERV-TCP/IP release 1.8d) with spool id 3308 for PICLIST@MITVMA.MIT.EDU; Fri, 15 Nov 2002 09:40:11 -0500 Received: from MITVMA (NJE origin SMTP@MITVMA) by MITVMA.MIT.EDU (LMail V1.2d/1.8d) with BSMTP id 0935; Fri, 15 Nov 2002 09:39:52 -0500 Received: from nameserv.rl.ac.uk [130.246.135.129] by mitvma.mit.edu (IBM VM SMTP Level 320) via TCP with ESMTP ; Fri, 15 Nov 2002 09:39:51 EST X-Comment: mitvma.mit.edu: Mail was sent by nameserv.rl.ac.uk Received: from sstdwkiwi (sstdwkiwi.ag.rl.ac.uk [130.246.189.231]) by nameserv.rl.ac.uk (8.8.8/8.8.8) with SMTP id OAA02221 for ; Fri, 15 Nov 2002 14:39:51 GMT References: <004b01c28c23$51b8ba40$6501a8c0@potshe01.pa.comcast.net> <006401c28ca1$b0a4aa40$6501a8c0@potshe01.pa.comcast.net> <009101c28caa$1eec0b30$0300a8c0@main> <007701c28cb1$6e1eaf80$6501a8c0@potshe01.pa.comcast.net> X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4807.1700 X-MIMEOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 Message-ID: <024201c28cb4$db1b8150$e7bdf682@sstdwkiwi> Date: Fri, 15 Nov 2002 14:39:51 -0000 Reply-To: pic microcontroller discussion list Sender: pic microcontroller discussion list From: "Alan B. Pearce" Subject: Re: [PIC]: 16F627 brown out? question To: PICLIST@MITVMA.MIT.EDU X-RCPT-TO: Status: R X-UIDL: 277600675 X-Evolution-Source: pop://mailinglist%40farcite.net@mail.farcite.net/ Mime-Version: 1.0 X-Evolution: 00000776-0000 >Based on Microchips definition to me of "brown out" >(oscillator running, no code execution observable). >Maybe this definition does not hold true to the >interpretation of the list. I do not think this is the Microchip definition of Brownout, but I may be wrong, and am prepared to be corrected. IIRC the Microchip brownout detector operates if the supply drops below 4.something volts, and is designed to detect sag in a 5V supply, and stop operation on a chip designed for 5V only operation. The detector is still fitted to chips that will work on lower voltages, but needs to be disabled for the low voltage operation. For what you are doing, I suspect you would be better off using the :LF version of the chip, which has the added advantage of being specified to 2V supply. This will give you some margin over what your current chip can do. As an aside, are you using the power up timer??? This will take 1024 cycles before the chip starts running its program, and at 32kHz that starts to become a significant part of your 150mS. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.