VNH7040AY，The 15 pins（sel0） of the chip have a voltage of about 7V, This is obviously abnormal，What might be the problem？ best wishes to you thanks

[leonardo miccoli]

​Hi,

As you mentioned the SEL0 pin is an input pin. The fact the it is polarized @ 7V seems that the device is damnaged, we suggest you to try with new fresh sample.

BR,

Leonrdo

[Lli.4]

Thank you for your reply.

When the 15 pin of vnh7040ay shows 7V voltage, it shows the following phenomenon:

1, it can still drive the motor forward and backward.

2, but the output voltage of the 19 pin of vnh7040ay is 0V. Normally, the output voltage of this pin should not be 0V when the motor is rotating.

3. Remove the chip vnh7040ay from the PCB, and the resistance between GND (3,4,5,6,7 of vnh7040ay) and VCC (10 of vnh7040ay) is about 100 ohm; The resistance between vnh7040ay15 pin and GND (3,4,5,6,7 of vnh7040ay) is about 100 ohm.

What are the possible causes of chip vnh7040ay damage

[leonardo miccoli]

Hi,
The fact that SEL0 (PIN 15) is internally supplied at 7V in an evident signal that the device is damaged, probably due to an EOS.
If the PIN 15 is fixed at High level and MS_EN (pin 20) is set High, based on Table 12 at page 24 of the datasheet, you should be able to monitor on Multisense (PIN 19) :
- the Current Monitor of HSA if SEL1=0
- Vcc Monitor if SEL1= High.
If this is not true probably the damaged is related not only to SEL0 input pin.
It is not easy to understand the root cause basing on limited info, only a physical analysis inside the chip could clear the part damaged and try to understand the reason .
As an intermediate step I suggest to share the application schematic and Layout, so that our application team could analyze them and investigate if any weakness that can damage the device.
BR,
Leonardo Miccoli