Hi,
I have constructed a DC-DC step-down converter using the MC34063. The circuit I use is very similar to the one shown here:
My circuit does not have the Zener, output side LED and input side protection diodes (TVS1 and D2 in the circuit). The rest of the circuit is quite similar.
The operating conditions for my circuit are as follows:
Vin : 10V to 30V. Vout : 5V Iout: 250mA
I tested the circuit at:
Vin: 10V, Vout: 5.3V, Iout: 250mA
I observe that the MC34063 is heating. I am unable to say whether this heating is acceptable.
You could help me by answering these questions:
- Is there an accurate/thumb-rule method of _measuring_ the amount of power dissipated in an IC (MC34063 in this case).
- Categorically confirm or deny that the MC34063 is likely to heat at the test conditions (Vin: 10V, Vout: 5.3V, Iout: 250mA).
- Methods to reduce the power dissipation in the MC34063 at these test conditions.
- Is the heating really a problem?
I realise that some of these questions are open-ended, but it would be great to get some tips from the experts. Thanks a lot for your time.
Thanks, Anand