Post by thread:[EE] Digital pots

Hi All I designed a circuit about a year ago using the DS1803 dual digital pot. At the time I looked around, and that was the best fit for my I2C requiremnts. However, the item is really pricy at R25 (~$4) apiece. Does anyone know of a better choice chip for; - I2C comms (essential) - 50K device - single or dual - not about to go obsolete - 256 steps - operate on 5V Regards Roland --------------------------------------------- This message was sent using MWEB Airmail. JUST LIKE THAT http://airmail.mweb.co.za/

On 10/21/05, spam_OUTcaonmailTakeThisOuTmweb.co.za <.....caonmailKILLspam@spam@mweb.co.za> wrote: > Hi All > > I designed a circuit about a year ago using the DS1803 dual digital pot. At the time I > looked around, and that was the best fit for my I2C requiremnts. However, the item is > really pricy at R25 (~$4) apiece. > > Does anyone know of a better choice chip for; > - I2C comms (essential) > - 50K device > - single or dual > - not about to go obsolete > - 256 steps > - operate on 5V In your circuit, is one end of the pot grounded? Regards, Mark markrages@gmail -- You think that it is a secret, but it never has been one. - fortune cookie

caonmail@mweb.co.za wrote: {Quote hidden}>Hi All > >I designed a circuit about a year ago using the DS1803 dual digital pot. At the time I >looked around, and that was the best fit for my I2C requiremnts. However, the item is >really pricy at R25 (~$4) apiece. > >Does anyone know of a better choice chip for; >- I2C comms (essential) >- 50K device >- single or dual >- not about to go obsolete >- 256 steps >- operate on 5V > > >Regards >Roland > > >--------------------------------------------- >This message was sent using MWEB Airmail. >JUST LIKE THAT >http://airmail.mweb.co.za/ > > > > Microchip has some spiffy digital pots. Xicor and BurrBrown (TI) have more flavors, tho. --Bob -- Note: To protect our network, attachments must be sent to attachKILLspamengineer.cotse.net . 1-520-777-7606 USA/Canada http://beam.to/azengineer

{Quote hidden}> On 10/21/05, .....caonmailKILLspam.....mweb.co.za <EraseMEcaonmailspam_OUTTakeThisOuTmweb.co.za> wrote: > > Hi All > > > > I designed a circuit about a year ago using the DS1803 dual digital pot. At the time I > > looked around, and that was the best fit for my I2C requiremnts. However, the item is > > really pricy at R25 (~$4) apiece. > > > > Does anyone know of a better choice chip for; > > - I2C comms (essential) > > - 50K device > > - single or dual > > - not about to go obsolete > > - 256 steps > > - operate on 5V > > In your circuit, is one end of the pot grounded? > > Regards, > Mark > markrages@gmail > -- No. (short answer) Regards Roland --------------------------------------------- This message was sent using MWEB Airmail. JUST LIKE THAT http://airmail.mweb.co.za/

>>Does anyone know of a better choice chip for; >>- I2C comms (essential) >>- 50K device >>- single or dual >>- not about to go obsolete >>- 256 steps >>- operate on 5V > >Sure I have seen something along this line in Analog Devices or Linear >Technology brochures going across my desk. New I had seen one - AD5290, 256 position I2C interface.

I think Microchip digital poti like MCP41050/MCP42050 fit your bills quite nicely. It may not be the best digital poti like those from AD or Maxim. But it will be relatively cheaper and not so soon to go obsolete. FEATURES * 256 taps for each potentiometer * Potentiometer values for 10k?, 50k? and 100k? * Single and dual versions * SPI serial interface (mode 0,0 and 1,1) * +/- 1 LSB max INL & DNL * Low power CMOS technology * 1 µA maximum supply current in static operation * Multiple devices can be daisy-chained together (MCP42XXX only) * Shutdown feature open circuits of all resistors for maximum power savings * Hardware shutdown pin available on MCP42XXX only * Single supply operation (2.7V - 5.5V) * Industrial temperature range: -40°C to +85°C Regards, Xiaofan {Original Message removed}

>-----Original Message----- >From: piclist-bouncesspam_OUTmit.edu [@spam@piclist-bouncesKILLspammit.edu] >Sent: 24 October 2005 10:27 >To: 'Microcontroller discussion list - Public.' >Subject: RE: [EE] Digital pots > > >I think Microchip digital poti like MCP41050/MCP42050 >fit your bills quite nicely. It may not be the best digital >poti like those from AD or Maxim. But it will be relatively >cheaper and not so soon to go obsolete. > >FEATURES >* 256 taps for each potentiometer >* Potentiometer values for 10k?, 50k? and 100k? >* Single and dual versions >* SPI serial interface (mode 0,0 and 1,1) The OP wanted an I2C interface however, which is a shame as they are very cheap. Intersil have a wide range of digi-pots (formaly Xicors parts), though I don't know how they compare on price. http://www.intersil.com/products/deviceresults.asp?i=10763 Regards Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. =======================================================================