LM5069: Can the UVLO pin be driven directly from an LVCMOS output?

Gaurav Agrawal

Part Number: LM5069
Other Parts Discussed in Thread: TPS2490, , TPS1663, TPS1653

Hello,

We are replacing TPS2490 in an existing design with LM5069, as TPS2490 is not available in stock with TI.

LM5069 does not have a logic driven enable pin, as in TPS2490. While the datasheet suggests to use an open drain driver on the UVLO pin to achieve this, we wish to minimize the changes in our existing design. Can UVLO pin be directly driven from an LVCMOS 3.3V logic signal (and not be connected to a voltage divider from the Vin pin)? This logic control needs to be supported before/during power ON, as well as during normal operation. A high on the LVCMOS signal should enable the LM5069 device, a low or float should keep it disabled.

Regards

Gaurav

over 1 year ago

0 Rakesh over 1 year ago

TI__Guru* 95791 points

Hi Gaurav,

We can use LVCMOS 3.3V logic signal to drive UVLO pin but floating state should be avoided.

TPS1663, TPS1653 are other alternatives to TPS2490 and LM5069

Best Regards,

Rakesh

0 Gaurav Agrawal over 1 year ago in reply to Rakesh

Intellectual 650 points

Thanks for the immediate reply Rakesh.

So, can I assume that in all such cases where the LVCMOS 3.3V logic is low (or less than 2.5V), the internal 21uA current source will be enabled and the FET will be held low by 2mA pulldown Gate current?

TPS1663, TPS1653 are both not in stock as well. So we would prefer to stick with LM5069. The switched drain load will be around 110uF @ 50V, and I think should be ok with the device.

Regards

Gaurav

0 Rakesh over 1 year ago in reply to Gaurav Agrawal

TI__Guru* 95791 points

Yes Gaurav. Correct.

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LM5069: Can the UVLO pin be driven directly from an LVCMOS output?