Rafael Dazcal

Trimming accuracy over temperature for SCI

Discussion created by Rafael Dazcal on Apr 19, 2010
Latest reply on Apr 19, 2010 by David Payne

Greetings,

 

Researching a bit in the forum I found out that this is a question that has been brought up several times.

 

Perhaps trimming accuracy over supply range and temperature should be described in the datasheet of each component, since I'm not sure it is the same for every MCU.

 

I found very useful information in the AN2496 and the AN2498, although it seemed to me that some info about accuracy didn't mach between the App Notes (maybe it's because they are about different MCUs).

 

I am using the MC9S08LC36 MCU and I need to establish a serial communication that will hold for a temperature range from 0ºC to 70ºC. I am using an external crystal but I would love to use the internal clock, if possible.

 

I don't wish to calibrate each individual MCU, so I would use the factory value that should come in the flash memory in a specific address.

 

But if I understand correctly, this will give me only 7% accuracy over temperature change (AN2498, page 2, second paragraph). So that is not good enough for serial communication, which I understand should be limited to 3%... am I correct?

 

I thank you in advance.

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