LM74202-Q1: Can OUT pin be negative in shutdown ?

Ken Henderson

Part Number: LM74202-Q1
Other Parts Discussed in Thread: LM76202-Q1,

Hello,

When the LM74202 or LM76202 is in shutdown (/SHDN low) the power FETs are off.

Can the voltage on the OUT pin be negative (below GND) in this condition?

I would like to use the part as a current limited ideal diode and there is the possibility that the load will be a negative voltage (e.g. reverse battery) so I would shut down the part in that case.

Thanks for any help, Ken

over 6 years ago

0 Karikalan Selvaraj over 6 years ago

TI__Genius 16305 points

Moving this to lokesh and he will get back on this.

Regards,

Kari.

0 Lokesh Ghulyani over 6 years ago in reply to Karikalan Selvaraj

TI__Expert 8630 points

Hello Ken,

We are looking into this and we will get back in couple of days.

0 Lokesh Ghulyani over 6 years ago in reply to Lokesh Ghulyani

TI__Expert 8630 points

Hello Ken,

It is not possible to connect negative voltage on OUT pins of LM76202-Q1 or LM74202-Q1 even with SHDN = Low. This will violate the absolute max ratings of the device.

0 Ken Henderson over 6 years ago in reply to Lokesh Ghulyani

Intellectual 670 points

Hi Lokesh,

Thanks for looking into this.

The abs max ratings say OUT to RTN is -0.3 to +62V

And RTN to GND is -62 to +0.3V

So doesn't that mean OUT to GND can be -62V to +62V ?

Thanks, Ken

0 Lokesh Ghulyani over 6 years ago in reply to Ken Henderson

TI__Expert 8630 points

Hello Ken,

It would not mean that OUT can be negative w.r.t GND. LM76202-Q1 or LM74202-Q1 can only support negative voltages on input for protection from reverse battery.

For supporting negative voltages on output, you can consider TPS26624 or TPS26625 devices. These have lower current rating (0.88A).

0 Ken Henderson over 6 years ago in reply to Lokesh Ghulyani

Intellectual 670 points

Hi Lokesh,

Thanks for clarifying. The TPS26625 looks like what I need.

Just as a follow up question, what are the differences between a LM76202 and a TPS26600 ?

Ken

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LM74202-Q1: Can OUT pin be negative in shutdown ?