I am using MC34063 in step down configuration but the converter switches off every cycle. Following are the calculations and specifications: Vin - 9 to 12V Vout - 5V Imax - 0.3A Rsc - 0.36 ohms L - 47uH 1.6A Ct - 270pf I have tried reducing the current limit resistor value (Rsc), but it didn't help. The usable current is below the designed rated current. I have attached an oscilloscope image showing the output voltage ripple on channel-1 and switching transistor emitter (pin-2 of MC34063A) voltage on channel-2. Note that the transistor switches off completely causing a low frequency ripple in the output voltage which is unnecessary. Kindly help.
Turns out that since it is a switching regulator, it switches OFF completely when the output voltage is more than what it is designed for which is exactly what I don't want. I have shifted my design to MC34166 which is a PWM controlled DC-DC converter and everything seems to be working fine. I am getting an output voltage ripple of 10-15 mV peak to peak @ 5 V o/p and no such 10 Hz ripple.