So here is the data sheet for the step up converter I am using:
http://www.sparkfun.com/datasheets/IC/MC34063A.pdf
The circuit I am trying to build is on page 5. I have double and triple checked to make sure everything is connected correctly. For some reason the diagram doesn't have units on some of the components, so here is what I plugged in:
.22 ohm for Rsc. For this, I placed four 1 ohm resistors in parallel. Each resistor has a 1/4 W power rating, is this a problem here? Do I need a higher power rating?
180 ohm for R at pin 8
330 pF for Co
100 pF for cap coming off Vin (12 V) at pin 6.
For the diode, it looks like a zener but the number code is for a Shottkey diode. I am using a Shottkey diode that has a higher voltage and current rating than the one shown.
Also, I am using a 180 uH inductor, not a 170.
First of all, am I assuming the right values for the caps and Rsc? Really wish they listed the units.
Secondly, here is what happened when I turned on the circuit. Vout started at 12 V, and slowly dropped to 0, and the chip started getting really hot. I have plenty of chips to spare, so I am not worried if I burn a couple out. I have replaced the chip, still nothing. Any suggestions?
http://www.sparkfun.com/datasheets/IC/MC34063A.pdf
The circuit I am trying to build is on page 5. I have double and triple checked to make sure everything is connected correctly. For some reason the diagram doesn't have units on some of the components, so here is what I plugged in:
.22 ohm for Rsc. For this, I placed four 1 ohm resistors in parallel. Each resistor has a 1/4 W power rating, is this a problem here? Do I need a higher power rating?
180 ohm for R at pin 8
330 pF for Co
100 pF for cap coming off Vin (12 V) at pin 6.
For the diode, it looks like a zener but the number code is for a Shottkey diode. I am using a Shottkey diode that has a higher voltage and current rating than the one shown.
Also, I am using a 180 uH inductor, not a 170.
First of all, am I assuming the right values for the caps and Rsc? Really wish they listed the units.
Secondly, here is what happened when I turned on the circuit. Vout started at 12 V, and slowly dropped to 0, and the chip started getting really hot. I have plenty of chips to spare, so I am not worried if I burn a couple out. I have replaced the chip, still nothing. Any suggestions?
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