---- START NEW MESSAGE --- Received: from cherry.ease.lsoft.com [209.119.0.109] by dpmail10.doteasy.com with ESMTP (SMTPD32-8.05) id AD136FB0288; Sun, 01 Feb 2004 13:18:11 -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 <14.00CC7FA1@cherry.ease.lsoft.com>; 1 Feb 2004 16:18:07 -0500 Received: from MITVMA.MIT.EDU by MITVMA.MIT.EDU (LISTSERV-TCP/IP release 1.8e) with spool id 3589 for PICLIST@MITVMA.MIT.EDU; Sun, 1 Feb 2004 16:18:02 -0500 Received: from MITVMA (NJE origin SMTP@MITVMA) by MITVMA.MIT.EDU (LMail V1.2d/1.8d) with BSMTP id 4706; Sun, 1 Feb 2004 16:16:52 -0500 Received: from bay8-dav38.bay8.hotmail.com [64.4.26.95] by mitvma.mit.edu (IBM VM SMTP Level 430) via TCP with ESMTP ; Sun, 01 Feb 2004 16:16:52 EST X-Warning: mitvma.mit.edu: Host bay8-dav38.bay8.hotmail.com claimed to be hotmail.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Sun, 1 Feb 2004 13:16:54 -0800 Received: from 66.143.159.161 by bay8-dav38.bay8.hotmail.com with DAV; Sun, 01 Feb 2004 21:16:54 +0000 X-Originating-IP: [66.143.159.161] X-Originating-Email: [jsears2027@hotmail.com] X-Sender: jsears2027@hotmail.com References: <37FB7AA6F5F9814FB634A7BF4C35A6F5640D0B@ESEALNT442.al.sw.ericsson.se> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-OriginalArrivalTime: 01 Feb 2004 21:16:54.0554 (UTC) FILETIME=[B7956FA0:01C3E908] Message-ID: Date: Sun, 1 Feb 2004 15:16:50 -0600 Reply-To: pic microcontroller discussion list Sender: pic microcontroller discussion list From: James Nick Sears Subject: Re: [PIC:] 16LF877A A/D To: PICLIST@MITVMA.MIT.EDU Precedence: list X-RCPT-TO: Status: U X-UIDL: 371856780 ----- Original Message ----- From: "Jan-Erik Soderholm XA (TN/PAC)" To: Sent: Saturday, January 31, 2004 10:49 AM Subject: Re: [PICLIST] [PIC:] 16LF877A A/D > James Nick Sears wrote : > > > From what I can see in the datasheet, in theory anyway, > > the performance should not decline with a longer Tad so > > I am curious. > > See figure 11-2 on page 128 in the data sheet. > > The C-hold capacitor will first be charged to the > input voltage ("acquisition"). Then it's disconected > from the inpout pin via the SS-switch and the AD-conversion > starts. During the conversion, the C-hold cap is slowly > discharged due to internal leakage, and a "too long" > conversion time will introduce errors. > > Jan-Erik. Good point. Thanks, Nick -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads .