OT: fast switched voltage regulators

[Haible Juergen]

I know this is a very off-topic question, not synth-related,
but I know the synth-diy list is the best source of information
for *any* electronic problem (;->)

All right, I'm looking for a tiny switched power supply chip
with internal power transistors (not more than 1 or 2 Watts
required) with the highest switching frequency available,
and with external control of the output voltage.
Small package (8 pins) would be great.

Who is making the fastest ones ? Over 1MHz is a *must*,
aiming for something like 5MHz or more. 

Any recommendations welcome.
Please answer privately to 
juergen.haible at nbgm.siemens.de

Thanks in advance,

JH.