Good news! LM78XX now availabe as switch mode regulators

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Boncuk

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Hi All,

this is really good news!

LM78XX have been used for many years and for many applications.

Especially supplying low voltage circuits up to 1A they have become "workhorses" for everyone.

The bitter pill: The higher the difference between input and output voltage the bigger the problems because of of heat dissipation.

The K78XX series is just equivalent to the LM78XX series, with a larger body, but pin pitch being the same (2.54mm=1/10").

The maximum efficiency is given as high as 97%.

Here is a data sheet.

Enjoy!

Boncuk
 

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WOW
it is a great news. Now we need to search who could sell us at various locations in retail-- houses like Farnel, RS Components , Mouser, Hendrikson, etc
 
Here's some similar products that have been available for some time...

**broken link removed** (1 amp version)
**broken link removed** (1 1/2 amp version)
**broken link removed** (2 amp version)

These are available at Digikey...
 
Last edited:
There sure are a lot of similarities between the "V" part and the "K" part datasheet. Even the wording seems identical.
I like how easy it is to generate negative voltages but I don't like the cost: $7.00 vs $0.50 is steep.
 
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I have recently used the MORNSUN brand of voltage regulators and so far they are working quite well, price is a little steep but gives a little extra peace of mind.
 
What is this spec actually?

I did not know they existed.

jbeng said:
Here's some similar products that have been available for some time...

**broken link removed** (1 amp version)
Click to expand...

From the specs in the data sheet, what does this means:?

short circuit input power 0.5 1.8 W
 
atferrari said:
I did not know they existed.



From the specs in the data sheet, what does this means:?

short circuit input power 0.5 1.8 W
Click to expand...

I figure the maximum power dissipation (nominal 0.5W and max. 1.8W) is meant for a shorted output.
 
Jaguarjoe said:
I like how easy it is to generate negative voltages but I don't like the cost: $7.00 vs $0.50 is steep.
Click to expand...

Considering no need for a heat sink, thus resulting in a smaller PCB the cost aren't as high as the pure chip.

Further, ICs are produced and calculated to reach the break even point quickly.

After the first 5 mio have been sold the price will certainly be reduced.

Boncuk
 
Hi,

Sometimes a switcher is the only way to go. This makes it simpler in those cases where the output is fixed. Next i'd like to see a variable output version, that would really kick it up
 
Hi,

Thanks for the link, that looks interesting too.
I was really referring to the kind of regulator where we have an input, an output, and an adjustment terminal where the external circuit can adjust the output by adjusting the adjust terminal
(ie feedback terminal).
 
you can try **broken link removed** from X-ON for 23 cents. Up to 1.8A 3v to 40v input DC to DC converter.
 
colin55 said:
you can try **broken link removed** from X-ON for 23 cents. Up to 1.8A 3v to 40v input DC to DC converter.
Click to expand...

I think your missing the point here. These include all of the passives so it's as simple as a regulator for a hobbyist. The part you are showing is a standard DC/DC IC which requires all the passives, inductor, resistor, diode...
 
Here is the BOM for external parts needed with the AP34063:

resistors: Rsc=0.11Ω, R1=trimpot 25K, R2=36K
capacitors: C1(Vin)=470µF/35-40V, Cr=470pF, C2(Co)=470µF/16V, C3(Vout)=100µF
diodes: D1=B240
inductors: L1=100µH, L2=1.0µH

Since there is no double part needed.

And the winner is: Colin55

Winning price: 99 herrings

What you have to put in for external components increases the required PCB area by the factor 4 to 5.

Boncuk
 
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That is not true. The only extra component is an inductor. I have the circuit working for the past 5 years - so don't tell me what is needed.
 
i think smd34063 or similar modern switchers can be managed within the space used by the models quoted by boncuk. perhaps collins concept need not increase the board space. basically let us realize the fixed voltage versions and they could be home-brew cheaper than cost of item suggested by boncuk.

@dirtylude,
if the component suggested by boncuk is checked, it would also have all these components and , it would also be called generic DC-DC converter, but bulk made by a company.
thus we should not bother to use 5 to 6 components, and home-brew one.

@collins55,
34063 cant work as DC Dc converter, without other components.
just one inductor cant make it up.
If you had made one, please publish, as it is not indicated in any datasheets and cant be logically apt.
 
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colin55 said:
That is not true. The only extra component is an inductor. I have the circuit working for the past 5 years - so don't tell me what is needed.
Click to expand...

You are a strange dude. I'm not certain if you intentionally try to cause confusion or not. Why wouldn't you just tell use how that is done rather than keeping it a secret? I've not seen a switcher that doesn't need a diode with its inductor but if you have a secret method for bypassing all of these components, let us know.

...and again, still not the point. I have no problem using a standard switcher with its components, but there are a lot of people that just want something with minimal pincount they can plug into a breadboard with a couple capacitors, which is what this thread is about. Personally I wouldn't pay $7 for that convenience, but others would.
 
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