N
Nicolae Fieraru
- Jan 1, 1970
- 0
Hi All,
I am very frustrated with the PIC16F84A and I don't understand what is going
on. I am trying to control a stepper motor with this chip (it is a circuit
from a book, using Darlington transistors and a hex buffer 4050). I managed
to program the chip fine, I measured the output of the ic. But when I
install it in the circuit, it blows the chip in a matter of seconds or
minutes while I fittle with the circuit and measure some signals. So far I
burned four of them, and they don't come too cheap. I initially presumed
that the stepper motor generates voltage spikes despite the protection
diodes placed on the transistors, but the last chip blew when I was driving
leds instead of the motor coils. When they blow, the oscillator doesn't work
anymore (I am using quartz crystals) and all the ouputs appear to the
programmer as the chip is erased.
Are these chips ultra-ultra-ultrasensitive to electrostatic electricity, to
overloading the outputs, to accidental shortcircuits or what is going on? I
worked for years with TTL and CMOS and analog IC's and I've never blown ic's
in such an easy way.
What are your comments about this matter? Have others experienced the
failure of these chips?
Regards,
Nicolae
I am very frustrated with the PIC16F84A and I don't understand what is going
on. I am trying to control a stepper motor with this chip (it is a circuit
from a book, using Darlington transistors and a hex buffer 4050). I managed
to program the chip fine, I measured the output of the ic. But when I
install it in the circuit, it blows the chip in a matter of seconds or
minutes while I fittle with the circuit and measure some signals. So far I
burned four of them, and they don't come too cheap. I initially presumed
that the stepper motor generates voltage spikes despite the protection
diodes placed on the transistors, but the last chip blew when I was driving
leds instead of the motor coils. When they blow, the oscillator doesn't work
anymore (I am using quartz crystals) and all the ouputs appear to the
programmer as the chip is erased.
Are these chips ultra-ultra-ultrasensitive to electrostatic electricity, to
overloading the outputs, to accidental shortcircuits or what is going on? I
worked for years with TTL and CMOS and analog IC's and I've never blown ic's
in such an easy way.
What are your comments about this matter? Have others experienced the
failure of these chips?
Regards,
Nicolae