Buck Converter for preventing Cold Cranking

Gencay Akyuz

Other Parts Discussed in Thread: LMR43620, LM5149

Is there any DC-DC buck converter IC that gives output voltage directly from input voltage while cold cranking occurs and how high currents can go?

over 2 years ago

+1 Marshall_Beck over 2 years ago

TI__Mastermind 35210 points

Hello,

The vast majority of available buck regulators are NMOS based, with bootstrap capacitor needing to be charged periodically, hence, an approximate 98-100% duty cycle.

The device can support full load current down to its minimum input voltage.

LM63635 and LMR43620 are example buck to consider for off-battery applications.

0 Gencay Akyuz over 2 years ago in reply to Marshall_Beck

Intellectual 305 points

Hello,

For my application LM5149 seems to be more suitable. In the product datasheet, it states Vout=Vin when Vin < 5.2V in typical application. Under this condition, can I get full load current? Can this IC be used to supply the circuit during cold crank down to 3.5V?

0 Marshall_Beck over 2 years ago in reply to Gencay Akyuz

TI__Mastermind 35210 points

Hello Gencay,

The device can support full load current and the device will continue to regulate at ~100% duty cycle if Vin remains above 3.5V.

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Buck Converter for preventing Cold Cranking