Digital potentiometer advice

proteus mcp42050

I'm looking for a cheap digital potentiometer, for opamp gain control.

The requirements for the design are: single supply 0-5V, SPI daisy-chained or I2C, 64-256 taps, independent A B and W terminals, 50-100k.

I was looking at datasheets from: Microchip MCP42050, Maxim MAX5478, Dallas DS1844, DS1868, but they aren't cheap (~ $2). Analog Devices or others are much more expensive...

Any ideas?

proteus vsm digital potentiometer

This market is very competitive and high volume. These prices reflect the amount of silicon it takes to hold all of the transistors.

potentiometer proteus vsm

Don't know about you exact requirements, but you could also consider an analog mux + discrete resistors as a way to control an opamp's gain.

There's some real cheap ICs out there.

My 2 cents...

CyBeRbLaK

ds1868 isis proteus

If you need a couple of ICs for design and tests purposes go to Maxim-IC web site and ask them for free samples:
**broken link removed**
If you think about mass-production, price on these things drops significantly with quantity ordered..
Regards,
IanP

pic digital potentiometer code

IanP said:

If you think about mass-production, price on these things drops significantly with quantity ordered..

Click to expand...

That's where my problem is. I wouldn't purchase big quantities, perhaps 100 or 200.

@cyberblak: I can't go analog mux route, my pcb will have 24 inputs... too complex.

Hmm... there must be a cheaper way of doing this

I too would like to know the cheaper way of doing it

several members asked me
and i made a free dll model for this chip within proteus vsm,
DS1868 dallas semis ,
you can download a copy here below...


The problem i found with this chip,
using picc compiler and also pic basic;

was that there drivers are rubbish and only load data,
The stackmux data dosnt seem to get acted on
nor does there driver send a stack select bit for stack read write etc

mainly becouse there is not enought clocks produced by the pic code drivers



i did enclose the source code for the pic test design

i am pretty sure the dll is ok for these extra modes over and above working fine
{ill do more tests in picc and add some modes to there pathetic driver
later on in the week}

works fine as a volume control {pots} within proteus vsm isis simulator
i will test it further and update it if needed posting a final type notice also

for now

enjoy...


basic load and pots outputs : modeled
fifo serial register and cout : modeled
sout stack mux : modeled
quasant current usage : modeled
offset substrate bias :modeled

chips fully modeled

pcb package soic16 dil14 tssop 20 {you may need to add soic type into ares}

sdssw show debug window default to switched off
it is a small window that just shows values on a pause of the sim
it shows potval 1 and 2 and also the ss bit status



and please feel free to email me a bug you find
{double check any errors fully i am sure the dll runs fine }



use this link for the latest version

**broken link removed**

if you want one made up however complex a dpot setup

pm me
but youll need to pay me coffee money

hello, the link you have given is broken. so could you please give a new link for dallas.dll