MC34063 is an integrated circuit which has all the essential components to make a DC-DC switching voltage regulator.
There are other popular switching regulators in the market. And the mc34063 IC is not the very best. But this chip is cheap.
As you can see from the block diagram. This chip contains an AND gate, an SR latch, two transistors, A 1.25V reference voltage and an op-amp configured as a comparator.
You can just choose any value of the component and think they will work.
There are very basic calculations which you need to perform in sequential order. The calculations are given in the datasheet.
You need to calculate in this particular sequence only.
- ton/toff
- (ton + toff)
- toff
- ton
- CT
- Ipk(switch)
- Rsc
- L(min)
- Co
You can also take the help of an online calculator for mc34063
http://www.nomad.ee/micros/mc34063a/
or you can create a spreadsheet.
You must read the SLVA252B Application of the MC34063 Switching Regulator
By following you can create the cheapest switching power supply.
There are a few considerations with this integrated circuit.
There is a lot of switching noise. So you will need a bigger capacitor if you want to dampen those noise signals.
If you want to reduce the size of the inductor used. Then you will need to use a higher switching frequency.
You need to remember that the L(min) you have selected is for a particular base frequency. The maximum frequency will be set up according to the load connected to it. And the maximum frequency of the oscillator is 100KHz according to the datasheet.
Leave a Reply