LM2670: Current adjust pin

Abed Meguenni

Part Number: LM2670
Other Parts Discussed in Thread: LM2673, LM2676, LM22676, , LM2678

Hi,

Currently i'm trying to find an alternative to the LM2676 because we can't found any stock. I have found the LM2673, the features seems similar (Voltage, Efficiency, Operating temperature, Body size...) except the pin configuration.

For the LM2676 the pin 5 is NC while the pin 5 of the LM2673 is for Current Adjust. What happen if i left the Current adjust pin NC ?

Best Regards,

Abed

over 3 years ago

0 Frank De Stasi over 3 years ago

TI__Guru 73645 points

Hello

You will need to place a resistor on the Ilimit pin to provide a finite current limit for the device; it can not be left open.

You may want to look at the LM22676 family of devices; they are also pin compatible.

Thanks

0 Abed Meguenni over 3 years ago in reply to Frank De Stasi

Prodigy 10 points

Hi Frank,

Thanks for the quick response about LM2673. Concerning the LM22676 :

- The oscillator frequency and the Junction to ambient thermal resistance aren't the same

Do you have something with same features and pin compatible ?

Regards,

Abed

0 Frank De Stasi over 3 years ago in reply to Abed Meguenni

TI__Guru 73645 points

Hello

If you are looking for an exact drop-in replacement, without changing components or PCB, then your choices would be LM2670, LM2676, or LM2678.

The LM2678 is a 5A device that should cover your current requirements; at least until you can procure the correct device.

At most you may need to replace the inductor to withstand the larger current of the LM2678.

Otherwise you would need to move to the LM226xx family of devices.

Thanks

0 Abed Meguenni over 3 years ago in reply to Frank De Stasi

Prodigy 10 points

Hi,

I have decided to go on the LM2670, seems equivalent except that it has a SYNC pin. So if i let the SYNC pin NC it will work as LM2676 ?

Thanks,

Abed

0 Frank De Stasi over 3 years ago in reply to Abed Meguenni

TI__Guru 73645 points

Hello

That should be OK.

Thanks

Power management

Power management forum

LM2670: Current adjust pin