SN74LVC1G79: Short circuit between VCC and GND of SN74LVC1G79

jeno.zhang

Part Number: SN74LVC1G79

Tool/software:

Hello,

During the customer's use of SN74LVC1G79, a large number of devices experienced VCC and GND short circuits. The quantity is approximately 800 pieces. Previously used without any short circuit issues. The schematic diagram is as follows. Could you please help analyze the possible causes of short circuits? Thanks！

3 months ago

0 Clemens Ladisch 3 months ago

Guru 316960 points

There are no decoupling capacitors.

What are the characteristics of the hall sensors' output signals?

What is connected to CON1? How are you protecting against overvoltage on +5V?

0 jeno.zhang 3 months ago in reply to Clemens Ladisch

Expert 2875 points

Hello，

What is connected to CON1? How are you protecting against overvoltage on +5V?
CON1 is connected to the controller, and there is no protection at the+5V position. What are the possible causes of VCC and GND short circuits?

Thanks！

0 Albert Xu1 3 months ago in reply to jeno.zhang

TI__Mastermind 38095 points

Hi Jeno,

Not having these decoupling capacitors are a possible cause of these Vcc/GND short circuits. There is not much else we can gather from just looking at the schematic.

Do you have any more information on where these signals are coming from and what the power supply is?

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SN74LVC1G79: Short circuit between VCC and GND of SN74LVC1G79