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STM32L072: Meaning of ''TTa'' as IO-Structure for PA0

Uwe Bonnes
Principal III
Posted on February 01, 2017 at 11:57

Hello,

in DocID027100 Rev 3, PA0 is marked to have an IO-Structure 'TTa' , but 'TTa' is not explained in Table 15.

Bye

12 REPLIES 12
Posted on February 03, 2017 at 07:37

Oh, I see. Thanks!

Jan

Posted on February 03, 2017 at 10:07

On STM32L0 devices, VDDA must be connected to VDD, ...

Why then having a separate VDDA pin in the first place ?

Connecting both internally would free a pin for GPIO functions on low pin count packages.

Posted on February 03, 2017 at 10:59

VDD and VDDA are kept separate to reduce  the impact of the digital noise on the analog section of the device.

It simplify making noise robust layout and eventually allows for an additional filter.

Connecting VDD to VDDA  or VSS to VSSA is evaluated for each device and for each package.

For the STM32L0, VDD and VDDA are connected internally only on the TSSOP14  package but VSS and VSSA are connected internally for packages from 32-pin and down.