Good switching regulators?

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Folks,

Does anyone make any good, fully integrated switching regulators for moderate power (in the 50 to 150mA range)? I like the efficiency of switchers, but I really like the simplicity of a standard linear + a couple of decoupling caps solution.

Anyone know of anything out there that might be nice to try out?

Thanks!

Clint

 

Clint

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There are many to try :)

Please tell us:

Input voltage and current
Output voltage and current

oddbudman

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oddbudman,

Quote:
Input voltage and current
Output voltage and current

Is like you asking for the efficiency percentage.

The OP has to tell us just the needed:
1. Output Power
2. Output Current
3. Output Ripple Voltage
4. Input Voltage (min to max)
5. Input maximum Current
5. If input-output isolation is needed

Michael.

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Altium Designer

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I like the lm2575 stuff, one of the cheaper switchers available and has the FET integrated

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Sorry I wasn't more specific. This was more of a general question, not a specific question about a specific project, so I can only give a range of the kinds of things I have wanted a good switcher for in the past.

1. Output Power - say 3.3V * 100mA, or 350mW or so
2. Output Current - 100mA will cover the majority of these cases
3. Output Ripple Voltage - Very good question. I tend to not pay much attention to ripple unless I am dealing with analog. I know. Bad design and planning on my part!
4. Input Voltage (min to max) - 4.5V to 24V (MAYBE 36V on occasion)
5. Input maximum Current - Usually a LOT more than I need, say 500mA available.
5. If input-output isolation is needed - No. Isolation is usually provided by step down transformer.

As for efficiency, I don't have any small battery power devices in mind, so super high efficiency isn't needed. Just about any switcher is going to be way more efficient than a linear regulator, especially with higher input voltages.

And thanks for the leads so far. I'll take a look at then and see how they stack up.

And as a newbie here, I have to ask: What the heck does "OP" stand for? Or do I not want to know?! --- Never mind! "Original Poster".

 

Clint

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Yes it means the ORIGINAL POSTER.

Now... You are talking busines. You couldn't be more specific.

Texas instruments has a big range of step down converters.

I have used the TPS5430 which has a 5V Output / up to 3A, but I am sure there are lower current adjustable versions of Step Down Converters.

National Semi. also has Step Down Converters.

A most known ic is the 34063 DC/DC converter.

Michael.

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Linear Technology has a lot of nice switchers, with a few special types like constant current types, or ones to drive push pull transformers.

There are literally thousands of types to choose from, from lots of manufacturers (TI, NS, LT, Maxim, Sipex, Onsemi, Analog Devices come to mind).

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Also with Linear Technology you can download their free SWCad software and design and simulate your switcher. It helps a lot when you need to zero in on a specific inductor spec and noise filtering. I have not use it but TI has a free spice as well. National Semiconductor has online Simple Switcher design help.

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If you don't want to mess around with all of the issues in determining the best inductor, saturation current, AC loss, DCR, Thermal properties, SFR, as well as the issues with layout that can cause instability, commonmode and differential mode noise, high ripple, etc, a company called Enpirion offers a power system on a chip or PowerSoC. It is a complete DCDC solution, just add input and output caps and your done! and by the way in about 25% the footprint of other DCDCs, with low noise and low ripple. As small and easy as a linear with the efficiency of a switcher.

DCDC DUDE

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DCDCDUDE wrote:
If you don't want to mess around with all of the issues in determining the best inductor, saturation current, AC loss, DCR, Thermal properties, SFR, as well as the issues with layout that can cause instability, commonmode and differential mode noise, high ripple, etc, a company called Enpirion offers a power system on a chip or PowerSoC. It is a complete DCDC solution, just add input and output caps and your done! and by the way in about 25% the footprint of other DCDCs, with low noise and low ripple. As small and easy as a linear with the efficiency of a switcher.

DCDC DUDE

Those Enpirion chips look NICE. They are exactly what I have wanted: a single chip solution to providing the power I need. There are only two issues I see with them:
1) They have a very limited input voltage
2) I can't get them through my "normal" sources (aka: Digikey and Mouser). Where do you get these little beasties?

Alwelch,

I have built a prototype switcher that can take up to 40VAC input and provides a 1A - 5V regulated output using a LM2595. I used there design software to fine tune the components. It is all SMD and it works great. The design software is very nice and easy to use. Unfortunately, the inductor is huge compared to the regulator (and it isn't exactly small), so it ends up taking up quite a bit of space.

That little experiment is one reason I wanted to see if I could find (with help!) something with integrated inductors and much smaller. Of course, I only need 100mA for most of my projects, so that should help shrink it down a bit.

 

Clint

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Clint, You should be able to use tiny inductors if you select a high frequency switcher. Coilcraft and others offer tiny inductors. I have not seen the Empiriron chips. If you select a canned supply make sure you have more than enough current for any future design additions or you could run out of current.

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I've just ordered some Fairchild FAN2002 buck converters for use with FPGAs and XMOS chips - 1A output in a tiny 3mm x 3mm package.

Leon Heller G1HSM

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Thanks Gents. The info here has helped me to do better filtering at Digikey to narrow things down to what will work. It does look like shooting for very high switching freqs can definitely get the inductor down to standard SMD sizes with the current ranges I need.

Now I just need to decide which way I really want to go and build a prototype or two (I'm leaning to a 100mA small supply for "normal" stuff and a 1A larger supply for designs that are going to need a bit more). Once they are designed and tested, it will be easy to integrate them into future projects.

 

Clint

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You can get Enpirion from Mouser.

Their 1A DCDC is in a 3x3 with inductor.

500mA is in 2.5x2.25

Dude