S12 ZVML31 no GDU Flag

[fabiansonnleitn]

Hello,

I am using a S12 ZVML31 for a sensorless BLDC application. When the voltage drops down to 5.8V I do not get a GDUF error due to low voltage. Instead the signals on high side are switched with the low side for 400us.

Please find attache a scope screenshot.

purple - HD pin

blue - high side gate

yellow - low side gate

green - can be ignored

The voltage drop on HD is due to an active short on the lowside, for breaking.

Does anyone know this Problem?

all the best,

Fabian

[iggi]

Hi,

The GDUF register will not indicate if HD voltage drops low. It indicates if HD voltage gets high by setting GHHDF bit.

How about to measure voltage on VLS_OUT pin too? And also, to check GLVLSF bit which indicates low level of VLS voltage supply.

Regards,

iggi

[fabiansonnleitn]

Thank you!

did a update on

    GDUCTR_GHHDLVL and 
    GDUCTR_GVLSLVL

now it works flawless

[iggi]

Nice to hear that.

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