HELP!!! with MC34063

[olasesi]

i need to step 3.1v-3.7v(input) to 5v (500ma)(output) using mc34063
Already tried different combination of resistors, inductors and capacitors...
also tried values from mc34063 calculator but no good result.....

anyone with help?.......please

specifics will be very much appreciated....
i also need to know how the output current can be varied

thanks in anticipation

 

[ArNvC]

I think there is one such application in the datasheet of the MC34063 itself. However most of the MC34063 utilizes a 12V or a 25V input. I'm not sure in what type of circuit you are using it.

Output current can only be boosted greater than 1.5 A.

 

[olasesi]

I think there is one such application in the datasheet of the MC34063 itself. However most of the MC34063 utilizes a 12V or a 25V input. I'm not sure in what type of circuit you are using it.

Output current can only be boosted greater than 1.5 A.

MC34063 utilizes 3v-40v input
and u can get a maximum current of 1.5A

so it still can be used..cos i require an input voltage of about 3.3v and an output of 5v(500mA or 0.5A)

 

[tpetar]

Try this configuration :






Also you can try MCP1640 but max current is 350mA, soon Microchip will show 500mA variant.
https://www.microchip.com/wwwproducts/devices.aspx?dDocName=en547080

Design is very simple and also there is no mistakes.

**broken link removed**


Up to 96% Typical Efficiency

800 mA Typical Peak Input Current Limit:

IOUT > 100 mA @ 1.2V VIN, 3.3V VOUT
IOUT > 350 mA @ 2.4V VIN, 3.3V VOUT
IOUT > 350 mA @ 3.3V VIN, 5.0V VOUT

Single Cell Input Boost Converter Design
https://ww1.microchip.com/downloads/en/AppNotes/01311a.pdf



:wink:

 

[tpetar]

As one more alternative see LM2731 SOT23-5 with input voltage range 2,7V-14V

 

[neddie]

This should get you going , 3 to 5.3V , add a pot to output to set voltage accurately.
It's just a sim , so you must at least build it to make sure it really works :0)
Use LTSpice. Great package and free. Hope all the files you need are included in the zip.
Cheers
Neddie

 

[tpetar]

There is calculator located here :

**broken link removed**

Also you can see existing EDABoard threads about this IC, there is tons of materials.