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MC33661 vs MC33662

Question asked by Erwan MARC on Jan 22, 2013
Latest reply on Aug 6, 2015 by Erwan MARC

Hello,

 

On one of our products, we placed a MC33661 after a LINUART: everything is OK.

Because part is now obsolet and no longer available at distributors, we switched to "equivalent" MC33662.

The batch just produced doens't work for LIN functions... we changed the chip back to MC33661 and it is OK...

 

A quick analyze shows that there is only the Break field (13 bits).

 

A deeper anamyze shows there is an important differences: comparing signals on Rx and Tx lines on µc side, we see delays.

On MC33661 we have about 12µs

On MC33662 we have about 25µs

Because we operate at 20kb/s, such delay stands for 1/2 bit then the LINUART can't read back its synch field and stops operations.

 

Do you have such known issue on this component and a workaround?

 

Regards

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