DC / DC Switched Step down converters without a self ?

[CerF BleU]

Hi

I want to find a DC / DC Switched Step-down converter without using a
self in the external components ... is it possible ?

thx

 

[Cyrus]

Tell us about what specs converter you want,( DC Input/output voltage &
current )

Cyrus

 

[CerF BleU]

"Cyrus" <CyrusM@fox.net> wrote in message news:<MOkQd.56186$Yu.48798@fed1read01>...

Tell us about what specs converter you want,( DC Input/output voltage &
current )

Cyrus

I want to convert 18V into ~3V. working current of about 0.1 , 0.2 mA
or less and an output current of 1A.
all the converters i found use a self (~20ľH).

is there some converter without a self ?

 

[Roger Hamlett]

"CerF BleU" <christophe.lucarz@gmail.com> wrote in message
news:e2a0b413.0502150227.210458bc@posting.google.com...

Hi

I want to find a DC / DC Switched Step-down converter without using a
self in the external components ... is it possible ?
Have a look at the National semiconductor site, the LM2788. Many

topologies are 'easier' with an inductor, but step-down, is simple to do
using a switched capacitor design like this.

Best Wishes

 

[Rob Gaddi]

Ok, thanks ... but the output current seems to be very low with that
type of converter. Is it possible to find one with 1A for output
current ?

Might be possible, but I'd doubt it. Problem with capacitor charge pump
regulators is that they're not as efficient as true inductive switchers.
Hence you see them get a lot of use at 50mA, 100mA out, but you're not
going to want to use one for heavy drive like a full amp.

So what's your beef with inductors anyhow? Did an RF choke kill your dog?

 

[tof]

"Roger Hamlett" <rogerspamignored@ttelmah.demon.co.uk> wrote in message news:<jVtQd.53$166.3@newsfe2-gui.ntli.net>...

"CerF BleU" <christophe.lucarz@gmail.com> wrote in message
news:e2a0b413.0502150227.210458bc@posting.google.com...
Hi

I want to find a DC / DC Switched Step-down converter without using a
self in the external components ... is it possible ?
Have a look at the National semiconductor site, the LM2788. Many
topologies are 'easier' with an inductor, but step-down, is simple to do
using a switched capacitor design like this.

Best Wishes

Ok, thanks ... but the output current seems to be very low with that
type of converter. Is it possible to find one with 1A for output
current ?