Direct replacement for 16F688

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- 3rd September 2006, 17:48
Christopher4187

Direct replacement for 16F688

Hi,

I have read through both datasheets and I believe that a 16F505 can be a direct replacement for a 16F688. I am using a 16F688 and I do not need any analog inputs, which is why I am looking at a 16F505. It looks like you can only run the 505 at 4MHz but for my application is does not matter. Can someone confirm my thoughts?

Thanks,

Chris
- 3rd September 2006, 18:28
mat janssen

You read the datasheet well. Is only for 4 MHz. max. what the datasheet says!
- 3rd September 2006, 19:12
Acetronics2

Hi, mat

12F508,509 and 16F505 have only a 2 level stack ... and a special addressing scheme ... " so little" things to verify ...

Worth a close look to the Datasheet ....

Alain
- 3rd September 2006, 19:17
mat janssen

Thanks Alain, but he gave so little info about his application, only he read well about the 4 MHz and no analog inputs.
- 3rd September 2006, 19:43
Christopher4187

I only need digital inputs/outputs, no requirement for a fast oscillator and no analog inputs. The footprint MUST be the same as the 16F688 and that is why I think the 16F505 will work the best.
- 3rd September 2006, 23:02
Dave

Christopher4187, Why do you need a replacement?

Dave Purola,
N8NTA
- 4th September 2006, 00:34
Christopher4187

I am selling a device where I use a 16F688. I originally thought I needed the 688 but after selling a few hundred units, the customer never wanted that option implemented and he never will. I can purchase a 16F688 for $1.28 and a 16F505 for $1.05. It is a matter of saving money.
- 4th September 2006, 13:29
Dave

Christopher4187, Oh..... I see.....

Dave Purola,
N8NTA
- 6th September 2006, 06:47
paul borgmeier

Quote:

Originally Posted by Christopher4187

I am selling a device where I use a 16F688. I originally thought I needed the 688 but after selling a few hundred units, the customer never wanted that option implemented and he never will. I can purchase a 16F688 for $1.28 and a 16F505 for $1.05. It is a matter of saving money.

How many do you plan to sell? If you make the change and sell a “few hundred “ more, you will save $69 – a thousand more, you will save $230. Is it worth changing and retesting a perfectly good working product for that kind of money (and risk that they might not work the same)? Consider leaving it as is and working on your “next” money maker instead. Or, if the money out of your pocket is an issue, why not charge $.25 more for the product and come out ahead. If that is not an option, you could split the difference with your customers and charge $.12 more. I know what I would do.
- 7th September 2006, 00:53
Christopher4187

Paul,

I thought about the same thing a while ago but it's better to have the mentality of saving money rather than spending it. I was thinking about changing a few other items on the board with the hopes of saving a few dollars for each unit. It was just a thought I was throwing around but maybe I was trying to pinch too many pennies.

Chris
- 7th September 2006, 01:20
mister_e

you could also compare the C serie against F serie.

EDIT: i thought it was usually cheaper.. seems not at digikey today. Maybe different from a supplier to another.