firefarzad
Junior Member level 1
Hello!
I have designed a circuit for a specific job, I used a LM2576 for regulating input voltage to 4.3V and a PIC18F4550 for doing the work!
if I supply the circuit with a 12V DC source, it works Fine!
but if I use a 17V PV panel, it works 10times faster!!!! and all the time synchronizing will fail.
I don't know why this happen? I used a 12MHz external crystal, and 2 capacitor 22p pulling down the crystal pins as always,
I have also tried internal crystal, but no difference!
Please help me with this unwanted overclocking!
I have designed a circuit for a specific job, I used a LM2576 for regulating input voltage to 4.3V and a PIC18F4550 for doing the work!
if I supply the circuit with a 12V DC source, it works Fine!
but if I use a 17V PV panel, it works 10times faster!!!! and all the time synchronizing will fail.
I don't know why this happen? I used a 12MHz external crystal, and 2 capacitor 22p pulling down the crystal pins as always,
I have also tried internal crystal, but no difference!
Please help me with this unwanted overclocking!