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Original question:

TAS2505: Short to Battery and GND Protection

LM48312: Short to Battery and GND Protection

Pial
Expert 7280 points
Part Number: LM48312

Dear team,

Dear Ivan,

I have a similar case as below thread: using LM48312, I would need to be protected against short to VBAT (where VBAT is ~32V,  >> PVDD) and short to GND.

Can we suggest some external circuitry for this functionality ? (I am already aware of this app note  which won't cover this usecase since Vcc max is about 6V for LM48312)

Also, LM48312 datasheet mentions an "advanced output short circuit protection with auto-recovery", can someone share some details about this ?

Many thanks in advance!

Best regards,

PA

  • 0
    TI__Guru** 104345 points
    Hi Pial,

    The protection from LM48312 will protect the device from short circuit to GND or voltage rail as high as its supply voltage, so higher than absolute maximum specs could damage the device. "Advanced" may refer to the fact that it is auto-recovery, so no reset is needed after removing the short circuit event.
    Protection from higher voltage than the supply voltage would require external protection circuitry.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0 in reply to Ivan Salazar
    TI__Expert 7280 points

    Hi Ivan,

    Thank you for your comments.

    Can you suggest some external protection circuitry example ? I was thinking of using 40V+ PMOS in line with the output, but a schematic extract would greatly help here!

    Many thanks in advance!

    Best regards,

    PA

  • 0 in reply to Pial
    TI__Guru** 104345 points
    Pial,

    Unfortunately we don't have an example design for this kind of protection. Perhaps there are similar application reports or TIDAs like SLOA236.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0 in reply to Ivan Salazar
    TI__Expert 7280 points

    Hello Ivan,

    Would that be possible to place DC blocking capacitors to this BTL class D amplifier output ?

    Thanks!

    PA

  • 0 in reply to Pial
    TI__Expert 7280 points

    PS: to illustrate what I meant, very simple block diagram below.

    In case that works, how would we select these blocking capacitors ? in my mind they would be quite small since they are connected with a high frequency H bridge and not an analog type of signal.. but I feel like it won't work for some obvious reason I don't see.

  • 0 in reply to Pial
    TI__Guru** 104345 points
    Pial,

    This might not be possible for a Class-D output like LM48312. It would only work for Class-AB (analog) output.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators