I have made a DC-DC converter using a LM2596S-5 regulator. The input is 12 V DC.
I thought PWM converters should have high degree of efficiency (hence low power dissipation), but even with 10mA load the regulator is a bit warm. I can touch it without big problems, but a few degrees warmer and I cannot touch it any more. Estimated somewhere between 50 and 60 deg C.
I have mounted a heat sink to the regulator.
Is this normal?
Diagram of the converter: