Voltage Regulator Requirements

[Leethal]

I would like a voltage regulator, preferably a LDO PMOS type but one that works at higher voltages and currents such as 5A and 30V. The requirement is to bring a 33.6V battery down to 30V (as it is too high for the equipment it is powering) till such a time that it has discharged enough (30V) that it no longer requires regulation possibly at this point the PMOS is fully on and therefore using little power.

I have seen the general block diagram with voltage reference, divider and error amplifier however none of these seem to be where VGate is up around 30V somewhere.

Is this possible and where would I make a start designing such a circuit?

 

[tpetar]

Switched:

LM2587T-ADJ
LM2678T-ADJ/NOPB
LM2679T-ADJNOPB
LT1071CTPBF
LT1071HVCTPBF
.
.
.
LT1084IT Vout max 28,5V

 

[Leethal]

I should have stated a Linear regulator

 

[tpetar]

Try LM338K linear regulator, its not LDO.

 

[Leethal]

Thanks Tepar. I was tring to avoid much power loss as the battery drops below the 30V regulated setting by having a very low resistance PMOS turned hard on below this point.