Post by thread:I/O current

Hi all, Quick question, PIC can handle 20 mA per I/O line. It means I can drive seven of the I/O-s in the same time with 20 mA ? Thanks, Peter Schultz

Yes. Look at the total consumption. It can only handle in the region of 100 to 120 mA in total. It should be fine. Which PIC you intend to use in this way. -----Original Message----- From: Peter <spam_OUTschupetTakeThisOuTDVP.COM> To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU <PICLISTKILLspamMITVMA.MIT.EDU> Date: Friday, March 27, 1998 2:22 AM Subject: I/O current >Hi all, >Quick question, PIC can handle 20 mA per I/O line. >It means I can drive seven of the I/O-s in the same time with >20 mA ? >Thanks, > >Peter Schultz >

In message <.....01BD58D3.2B8C4A40.schupetKILLspam.....dvp.com>, Peter <EraseMEschupetspam_OUTTakeThisOuTDVP.COM> writes >Hi all, >Quick question, PIC can handle 20 mA per I/O line. >It means I can drive seven of the I/O-s in the same time with >20 mA ? Look at the Absolute Maximum Ratings. For instance, the 16C84 has a max. current of 100 mA into the VDD pin. Leon -- Leon Heller: leonspam_OUTlfheller.demon.co.uk http://www.lfheller.demon.co.uk Amateur Radio Callsign G1HSM Tel: +44 (0) 118 947 1424 See http://www.lfheller.demon.co.uk/dds.htm for details of my AD9850 DDS system. See " "/diy_dsp.htm for a simple DIY DSP ADSP-2104 system.

Most (all?) of the PICs I'm aware of have a limit for the total of all pins of 50mA, so no, you cannot drive all 7 segments at 20mA each since this would be... ummm, ahhh... 140mA, which would seriously exceed the absolute maximum rating for the chip. Sorry - Martin. @spam@mrgreenKILLspamNOSPAMbigfoot.com To reply, remove the NOSPAM from the reply address. Stamp out SPAM everywhere!!! On Thu, 26 Mar 1998 16:21:01 -0800, you wrote: >Hi all, >Quick question, PIC can handle 20 mA per I/O line. >It means I can drive seven of the I/O-s in the same time with >20 mA ? >Thanks, > >Peter Schultz

> From: Peter <KILLspamschupetKILLspamDVP.COM> > Hi all, > Quick question, PIC can handle 20 mA per I/O line. Yes. > It means I can drive seven of the I/O-s in the same time with > 20 mA ? Read the manual carefuly! Accoding to 16C84 datasheet : Max current sunk by PORTA - 80mA Max current sourced by PORTA - 50mA Max current sunk by PORTB - 150mA Max current sourced by PORTB - 100 mA So you can use only sunked current from PORTB to handle 20x7=140mA. Alex Torres, Kharkov, Ukraine (exUSSR) RemoveMEaltorTakeThisOuTchat.ru 2:461/28@FidoNet www.geocities.com/SiliconValley/Lab/6311

Hi! 26-Mar-98 16:21 Peter (spamBeGoneschupetspamBeGoneDVP.COM) wrote about I/O current >> Hi all, >> Quick question, PIC can handle 20 mA per I/O line. >> It means I can drive seven of the I/O-s in the same time with >> 20 mA ? Yes. But it doesn't men You have a valid levels for '0' and '1'. These levels will depend on a lot of factors: load current, Vdd, temperature... Please re-read complete datasheet (not hilightes only!). Tables and plots are of special interest for You. -- Vladimir M. Klochko