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Buck DC-DC converter ICs, with internal MOSFET and freewheeling diode ???

Question asked by esm. on Mar 11, 2012
Latest reply on Feb 24, 2014 by LucaV

Hi.

I am looking for a buck converter IC available in a small SMD package like SOT-23 (or other small one) to a power supply with these parameters:

 

Vin = 16 to 30VDC

Vout = 4.4VDC

Iout = 250mA

 

The maximum output peak current is also 250mA. The 4,4V rail will be used to supply voltage to a constant current supply (to a Li-Ion battery charge management IC). If possible, a higher output current capability would be better, but 250mA is enough for me.

 

It would be much better a buck converter IC who meet the parameters above and doesn't require the use an external MOSFET and also not require an external freewheeling diode. I didn't found.

 

I'm using TPS63000 from Texas Instruments in some designs. It is a buck-boost converter that doesn't need an external MOSFET nor an external freewheeling diode when operates in buck mode.

 

I have many 1A SMD inductors with values from 4.7uH to 68uH. I just need to define which IC to be used. If don't find an IC who meet the parameters above, I will need to use a LM2596-ADJ buck converter from National Semiconductors to do the buck conversion, but it requires much more PCB space than the IC I am looking for.

 

Somebody know some good ICs to meet the parameters above?

Preferentially, ICs that doesn't require external MOSFET, freewheeling diode and is availabe in a small SMD package like SOT-23.

 

Or some other suggestions of ICs with bigger size package that doesn't require external MOSFET nor a freewheeling diode ????

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