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The purpose of this group is to foster exchange of information on the Texas Instruments MSP430 family of microcontrollers and related tools. Everyone welcome, all levels of familiarity/expertise.
MSP430 ADC Linearity - "paddu.koti" - Oct 28 23:03:15 2009
Hi,
I need your help regarding MSP430's ADC.
I am testing ADC in MSP430F54xx using internal REF,
but found that linearity is not good,I am getting a difference of about 4%.
Please let me know if there is a solution to overcome this or if there is any application note from TI.
Thankyou in advance
Regards.
Paddu
------------------------------------
______________________________
Stellaris® MCU Family: New Parts, New Package, New Price.
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
I need your help regarding MSP430's ADC.
I am testing ADC in MSP430F54xx using internal REF,
but found that linearity is not good,I am getting a difference of about 4%.
Please let me know if there is a solution to overcome this or if there is any application note from TI.
Thankyou in advance
Regards.
Paddu
------------------------------------
______________________________
Stellaris® MCU Family: New Parts, New Package, New Price.
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: MSP430 ADC Linearity - Michael - Oct 29 9:12:17 2009
Hello Paddu,
> I am testing ADC in MSP430F54xx using internal REF, but found that
> linearity is not good,I am getting a difference of about 4%.
I guess the first question would be how you measured this (what's the error inherent to your measurement setup).
> Please let me know if there is a solution to overcome this or if
> there is any application note from TI.
I know the F2xx devices come with ADC calibration data in the INFO FLASH (segment A?) from factory. It makes sense the F5xx should have it too, if you haven't erased the info flash. Check the documentation.
Regards,
Michael K.
--- In m...@yahoogroups.com, "paddu.koti" wrote:
>
> Hi,
>
> I need your help regarding MSP430's ADC.
>
> I am testing ADC in MSP430F54xx using internal REF,
> but found that linearity is not good,I am getting a difference of about 4%.
> Please let me know if there is a solution to overcome this or if there is any application note from TI.
>
> Thankyou in advance
>
> Regards.
> Paddu
>
------------------------------------
______________________________
Stellaris® MCU Family: New Parts, New Package, New Price.
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
> I am testing ADC in MSP430F54xx using internal REF, but found that
> linearity is not good,I am getting a difference of about 4%.
I guess the first question would be how you measured this (what's the error inherent to your measurement setup).
> Please let me know if there is a solution to overcome this or if
> there is any application note from TI.
I know the F2xx devices come with ADC calibration data in the INFO FLASH (segment A?) from factory. It makes sense the F5xx should have it too, if you haven't erased the info flash. Check the documentation.
Regards,
Michael K.
--- In m...@yahoogroups.com, "paddu.koti"
>
> Hi,
>
> I need your help regarding MSP430's ADC.
>
> I am testing ADC in MSP430F54xx using internal REF,
> but found that linearity is not good,I am getting a difference of about 4%.
> Please let me know if there is a solution to overcome this or if there is any application note from TI.
>
> Thankyou in advance
>
> Regards.
> Paddu
>
------------------------------------
______________________________
Stellaris® MCU Family: New Parts, New Package, New Price.
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
RE: Re: MSP430 ADC Linearity - Mike Raines - Oct 29 10:54:51 2009
Hey Guys,
I needed to know about the ADC calibration data awhile ago, and asked TI about it's
location on the F5438 chip. Below is their response:
For the older 2xx chips, the calibration data was located in INFOA, which could be erased (even though that section of memory has a lock-feature). The 5xx series is different. The calibration data is located in flash memory but it cannot be written to or erased. The 5xx User's Guide (page 33 -- section 1.9) shows the memory
map in a tabular form. From page 86 of the 5438
datasheet shows the calibration info
to be located at 0x01A00. The table in the User's Guide indicates this section cannot be
erased and a PUC reset is generated if that section of memory is accessed.
Good luck with your linearity problems,
Mike Raines
________________________________
From: m...@yahoogroups.com [mailto:m...@yahoogroups.com] On Behalf Of Michael
Sent: Thursday, October 29, 2009 9:12 AM
To: m...@yahoogroups.com
Subject: [msp430] Re: MSP430 ADC Linearity
Hello Paddu,
> I am testing ADC in MSP430F54xx using internal REF, but found that
> linearity is not good,I am getting a difference of about 4%.
I guess the first question would be how you measured this (what's the error inherent to your measurement setup).
> Please let me know if there is a solution to overcome this or if
> there is any application note from TI.
I know the F2xx devices come with ADC calibration data in the INFO FLASH (segment A?) from factory. It makes sense the F5xx should have it too, if you haven't erased the info flash. Check the documentation.
Regards,
Michael K.
--- In m...@yahoogroups.com, "paddu.koti"
wrote:
>
> Hi,
>
> I need your help regarding MSP430's ADC.
>
> I am testing ADC in MSP430F54xx using internal REF,
> but found that linearity is not good,I am getting a difference of about 4%.
> Please let me know if there is a solution to overcome this or if there is any application note from TI.
>
> Thankyou in advance
>
> Regards.
> Paddu
>
[Non-text portions of this message have been removed]
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
I needed to know about the ADC calibration data awhile ago, and asked TI about it's
location on the F5438 chip. Below is their response:
For the older 2xx chips, the calibration data was located in INFOA, which could be erased (even though that section of memory has a lock-feature). The 5xx series is different. The calibration data is located in flash memory but it cannot be written to or erased. The 5xx User's Guide
Good luck with your linearity problems,
Mike Raines
________________________________
From: m...@yahoogroups.com [mailto:m...@yahoogroups.com] On Behalf Of Michael
Sent: Thursday, October 29, 2009 9:12 AM
To: m...@yahoogroups.com
Subject: [msp430] Re: MSP430 ADC Linearity
Hello Paddu,
> I am testing ADC in MSP430F54xx using internal REF, but found that
> linearity is not good,I am getting a difference of about 4%.
I guess the first question would be how you measured this (what's the error inherent to your measurement setup).
> Please let me know if there is a solution to overcome this or if
> there is any application note from TI.
I know the F2xx devices come with ADC calibration data in the INFO FLASH (segment A?) from factory. It makes sense the F5xx should have it too, if you haven't erased the info flash. Check the documentation.
Regards,
Michael K.
--- In m...@yahoogroups.com
>
> Hi,
>
> I need your help regarding MSP430's ADC.
>
> I am testing ADC in MSP430F54xx using internal REF,
> but found that linearity is not good,I am getting a difference of about 4%.
> Please let me know if there is a solution to overcome this or if there is any application note from TI.
>
> Thankyou in advance
>
> Regards.
> Paddu
>
[Non-text portions of this message have been removed]
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: MSP430 ADC Linearity - bungalow_steve - Oct 31 1:28:27 2009
A/D Gain and bias erros can be software corrected, but linearity cannot, it's the limiting
factor in A/D performance.
this is assuming you are using the word linearity as the max difference between a straight line and the measured A/D output throughtout the A/D range
--- In m...@yahoogroups.com, "paddu.koti" wrote:
>
> Hi,
>
> I need your help regarding MSP430's ADC.
>
> I am testing ADC in MSP430F54xx using internal REF,
> but found that linearity is not good,I am getting a difference of about 4%.
> Please let me know if there is a solution to overcome this or if there is any application note from TI.
>
> Thankyou in advance
>
> Regards.
> Paddu
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
this is assuming you are using the word linearity as the max difference between a straight line and the measured A/D output throughtout the A/D range
--- In m...@yahoogroups.com, "paddu.koti"
>
> Hi,
>
> I need your help regarding MSP430's ADC.
>
> I am testing ADC in MSP430F54xx using internal REF,
> but found that linearity is not good,I am getting a difference of about 4%.
> Please let me know if there is a solution to overcome this or if there is any application note from TI.
>
> Thankyou in advance
>
> Regards.
> Paddu
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )