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Guest
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differences between PIC18F2221 and PIC18F2220 |
Posted: Sat Oct 10, 2009 12:33 pm |
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hello,
can anybody tell me what the differences between those two PICs are?
Why 18F2220 costs $4.05 and the latter mere $1.93
thanks for clarifying. |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Sat Oct 10, 2009 2:33 pm |
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Download both data sheets and compare them. Each data sheet has
a table of features, listing peripheral modules, RAM, and ROM size.
Compare those tables. To answer your question, this is what we would
have to do. It's better if you do it.
Here's the Microchip Data Sheet finder page. Bookmark this page.
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2046&var=an
Click on "8-bit PIC Microcontrollers" and select the PIC in the drop-down
box. It will go to the webpage for the PIC and you can download the
data sheet there. |
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Ttelmah Guest
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Posted: Sat Oct 10, 2009 2:46 pm |
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You have to remember that with any chip, some models are more popular, and will hence be made in larger quantities, leading to cheaper prices.
The two chips are very similar, but the 21, is the newer product, and is really designed to do everything the older chip does, with some extras (more features in the PWM, and higher speed on the internal oscillator). The pricing is a result of the older chip being sold at it's 'old' price, to customers who have code writen for this, and don't want to upgrade to the latter chip, while the 21, price reflects larger quantities now being produced of this, and price reductions that have appeared on latter chips.
Pricing on semiconductors is always very variable. While a figure is 'quoted' at quantities by the manufacturer, if you have a half way reasonable 'buyer', and start looking at quantities over 100K, don't be surprised if you can massively beat the 'quoted' price. The 21 price, almost certainly reflects it being used in quantity by a customer, and could shoot up, if this particular demand disappeared. It is often well worth getting 'call off' prices to avoid this if you are intending to use a good quantity.
Best Wishes |
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Guest
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Posted: Sun Oct 11, 2009 9:39 am |
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thank you guys for the replies.
The thing is it is not possible to download the PIC18F2221's datasheet. It ends up with "File not found" message.
Code: | microchip.com/wwwproducts/Devices.aspx?dDocName=en024612 |
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Ttelmah Guest
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Posted: Sun Oct 11, 2009 10:25 am |
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Several chips have this 'hiccup' on the current Microchip site. Just pull the 4321 data sheet. It includes the 2221.....
Best Wishes |
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Guest
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Posted: Sun Oct 11, 2009 10:44 am |
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oh, you are right,
thanks a lot |
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