St10F269 VAREF problem

[jasonsyj]

Posted on November 09, 2007 at 15:43

St10F269 VAREF problem

[jasonsyj]

Posted on November 07, 2007 at 20:43

Hi, I am now using LM4040A50IDBZR for VAREF.

My problem is I only get about 2v on VAREF pin, sch attached. I used it on C167CS, no problem at all, would you please give me some idea why this happened.

Also any recommend for voltage Reference chip for ST10F269 or ST10F276

thank you

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Attachments :

ST10F269.JPG : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0Ks&d=%2Fa%2F0X0000000bXn%2FAjf2IE4BGz..IZ_mu5pna3Xp1MTnU4XCS4DsLf6399M&asPdf=false

[jasonsyj]

Posted on November 08, 2007 at 20:48

BTW: REG is 12V or 24V

[najoua]

Posted on November 09, 2007 at 07:11

Hello jasonsyj,

The problem might be caused by the difference in Iaref on both devices.

You can refer to the enclosed schematics of the FS FORTH boards based on the ST10F269 and the ST10F276 for more details about the hardware on VAREF pin (page 2 ).

I hope this helps you.

Best regards,

Najoua.

[ This message was edited by: Najoua on 15-11-2007 13:19 ]

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Attachments :

Eva269_0.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0GI&d=%2Fa%2F0X0000000bXl%2FHOtcdBZCK_gNYN6O1TAnYK4dh2LAGztXE7QdAEZ98X4&asPdf=false

Eva27x_0c.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0ID&d=%2Fa%2F0X0000000bXk%2FcTe9ebB1N5MtJZB46WvG7Fsv2LxG.koGOWbV8M4oa8U&asPdf=false

[jasonsyj]

Posted on November 09, 2007 at 15:43

thank you for your help

but what part number for V4 on your sch?

thank you again