AW32 problems in 5V

[JohnnyS2K]

Hi to all,

       I have made a little LED blink application for the AW32 MCU (MC9S08AW32 CFGE) and programmed with the DEMOQE board through the BDM connector. I have tested the application with a supply voltage of 3.3V (BDM connector) and it works fine, but, when I supply the AW32 MCU with 5V (in other board with the LM2575-5.0) the power supply enter in short circuit (protection) and after some trys the AW32 MCU is damaged entering in internal short circuit (the BDM resets itself when I connect the MCU).

       My question is: the AW32 can really use 5V as supply voltage? Does someone have made some project with the same components? What can be wrong?

Thanks

[JohnnyS2K]

Worked !!! If I connect the pins VSSAD, VDDAD, VREFL and VREFH to the respective signals the MCU works properly in 5V. Funny, in 3,3V these pins can be left unconnected without problems...

Thanks

Johnny

[JohnnyS2K]

Hi Fábio,

  The VSSAD, VDDAD, VREFL and VREFH are left unconnected in the same fashion as when I supply the MCU with the BDM connector. I will try to connect these pins to the respective signals and see if it works.

Thanks

Johnny

[JohnnyS2K]

Hi JimDon,

    I'm only connecting the VDD pin when I program the MCU, and in that way the MCU works, but when I disconnect the BDM cable and put the MCU on other board with a 5v supply then problem occurs.

Thanks

[fabio]

Hi,

Are you sure that the whole chip is being supplied with 5V (including VDDAD)?

The DS states that the maximum allowed difference between VDD and VDDAD is 100mV.

Best regards,


Message Edited by fabio on 2008-07-04 09:01 AM

[JimDon]

The AW32 is good at 5V.

Please be sure you did NOT connect VDD pin from the QE board.