LMZ14203H

Daan Stelma

Other Parts Discussed in Thread: LMZ14203H

When in negative mode, what are the requirements for Vin?

For example, is it possible to get Vout: -15VDC from Vin: 12VDC

and

For example, is it possible to get Vout: -5VDC from Vin: 12VDC

Also in this case what would be the current rating compared to normal operation?

Is there a minimum voltage difference required like the case for possitive operation?

Vin should be Vout +3VDC

0 Frank De Stasi over 8 years ago

You can get +12Vin to -15Vout and +12Vin to -5Vout.

The sum of Vin and the magnitude of Vout must stay within the maximum input voltage of 42V.

The maximum output current will be less than for a buck. It is approximately:

Iout=(ICL-(DI/2))*(Vin/(Vin+Vout))

DI=(1/(Fs*L))*(Vin*Vout/(Vin+Vout))

Use absolute values in Vout and Iout, ICL is the current limit

Vin and Vout can have the same magnitude since it is a buck-boost

0 Daan Stelma over 8 years ago in reply to Frank De Stasi

Thank you,
only L will be unknown since it is a module..
or has to be calculated back from knowing it is 3 amp in possitive operating mode.

0 Frank De Stasi over 8 years ago in reply to Daan Stelma

In the LMZ14203H the L is 10uH

Power management forum