Post by thread:[PIC]: Converting PIC outputs to CMOS 4000 compati

Anyone have an idea of how to properly (or simply) convert the outputs of a PIC so that they can interface with 4000 series CMOS logic? I tried searching the FAQ, but really couldn't find anything. Is it as simple as adding an open collector output pulled up to the voltage my CMOS 4000 logic is running at?? Any help appreciated. Thanks Dan -- http://www.piclist.com hint: To leave the PICList spam_OUTpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

If the cmos (4000) power is 5 volts, then nothing is required. If cmos is other than 5 volts, then you are correct. Rick "Mccauley, Daniel H" wrote: {Quote hidden}> Anyone have an idea of how to properly (or simply) convert the outputs > of a PIC so that they can interface with 4000 series CMOS logic? > I tried searching the FAQ, but really couldn't find anything. > > Is it as simple as adding an open collector output pulled up to the > voltage my CMOS 4000 logic is running at?? > > Any help appreciated. > Thanks > > Dan > -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam@spam@mitvma.mit.edu

Mccauley, Daniel H wrote: > Anyone have an idea of how to properly (or simply) convert the outputs > of a PIC so that they can interface with 4000 series CMOS logic? Just connect them as long as the PIC and CMOS logic are running at the same supply voltage. What voltage are the two running at? ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestKILLspammitvma.mit.edu

The CMOS chips will be running at 15V while the PIC is at 5V. Thanks Dan > Anyone have an idea of how to properly (or simply) convert the outputs > of a PIC so that they can interface with 4000 series CMOS logic? Just connect them as long as the PIC and CMOS logic are running at the same supply voltage. What voltage are the two running at? ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam.....mitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspam_OUTTakeThisOuTmitvma.mit.edu

On Thu, 5 Feb 2004 08:39:25 -0500, you wrote: >The CMOS chips will be running at 15V while the PIC is at 5V. >Thanks >Dan In which case you can't use an 'open-collector' PIC pin pulled up to +15V as the earlier post implies, as the PIC's input diode will pull it down to +5V. The simplest way would be an external transistor (or FET) with a collector pullup to +15V For CMOS to PIC you can use a resistive divider. -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestspam_OUTmitvma.mit.edu

Mccauley, Daniel H wrote: > The CMOS chips will be running at 15V while the PIC is at 5V. There are level converter chips for this purpose. That's probably the best answer if there are a lot of lines that need to be converted. Otherwise, the simplest do it yourself method is probably a logic level N channel FET and pullup resistor. You can do it with an NPN transistor too, but it requires an additional base transistor. Both these methods invert, and the output fall time will be fast but the rise time dependent on the pullup resistor. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList @spam@piclist-unsubscribe-requestKILLspammitvma.mit.edu

>Otherwise, the simplest do it yourself method is probably a logic >level N channel FET and pullup resistor. You can do it with an >NPN transistor too, but it requires an additional base transistor. ^^^^^^^^^^ I think you meant resistor :)) The conversion chips for driving out from the PIC are CD4049 or CD4050 depending on non-inverting or inverting are better suited to your requirements. If you want to come the other way then resistors should suit, but if you want bi-directional then it gets trickier. -- http://www.piclist.com hint: To leave the PICList KILLspampiclist-unsubscribe-requestKILLspammitvma.mit.edu

Alan B. Pearce wrote: >> Otherwise, the simplest do it yourself method is probably a logic >> level N channel FET and pullup resistor. You can do it with an >> NPN transistor too, but it requires an additional base transistor. > ^^^^^^^^^^ > > I think you meant resistor :)) Oops. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

Olin Lathrop wrote : > Otherwise, the simplest do it yourself method is probably a > logic level N channel FET and pullup resistor. You can do > it with an NPN transistor too, but it requires an additional > base transistor. "base *resistor*", not ? :-) :-) Jan-Erik. This communication is confidential and intended solely for the addressee(s). Any unauthorized review, use, disclosure or distribution is prohibited. If you believe this message has been sent to you in error, please notify the sender by replying to this transmission and delete the message without disclosing it. Thank you. E-mail including attachments is susceptible to data corruption, interruption, unauthorized amendment, tampering and viruses, and we only send and receive e-mails on the basis that we are not liable for any such corruption, interception, amendment, tampering or viruses or any consequences thereof. -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestspamBeGonemitvma.mit.edu

At 07:54 AM 2/5/2004 -0500, you wrote: >Anyone have an idea of how to properly (or simply) convert the outputs >of a PIC so that they can interface with 4000 series CMOS logic? >I tried searching the FAQ, but really couldn't find anything. > >Is it as simple as adding an open collector output pulled up to the >voltage my CMOS 4000 logic is running at?? A 4049/4050 (Vdd=5V) will convert from the 4000 CMOS to PIC. (inverting / non-inverting hex buffer) A MC14504 will convert from PIC to 4000 CMOS (hex level shifter). It can go the other way too, but the 4040/50 are cheaper. This is convenient (no extra parts, 6 lines per SOIC). For just one or two lines, if speed and power consumption are unimportant, an open drain/collector inverter as others have described is more than okay. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" TakeThisOuTspeffEraseMEspam_OUTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

At 05:54 AM 2/5/2004, Mccauley, Daniel H wrote: >Anyone have an idea of how to properly (or simply) convert the outputs >of a PIC so that they can interface with 4000 series CMOS logic? >I tried searching the FAQ, but really couldn't find anything. > >Is it as simple as adding an open collector output pulled up to the >voltage my CMOS 4000 logic is running at?? What voltage is the 4000 series CMOS operating from? dwayne -- Dwayne Reid <dwaynerEraseME.....planet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 20 years of Engineering Innovation (1984 - 2004) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestmitvma.mit.edu