With the most limited of parts I want to be able to create a circuit that can power my PIC, but also protect it and the other components. I require my circuit to operate as far down as 7v, be able to bad connections for a slipt second without the PIC resetting, current and voltage protection. 7805 was what I was first using but found this limiting and not ideal. I am working with small SMD devices and small is the word
The supply voltage is from 0v to 17v, spikes can go up to 27v, then a zener will clamp it. I had been looking at using a transistor with a zener on the base to control the voltage for the PIC. I don't require much power to run the PIC, most of the other circuit will run off the high voltage rail of 9 to 17v.
I had seen some use of a mosfet, with the ability to turn off if the polls are reveresed thus protecting the circuit which I thought was good, as well as acting as a current limiting device.
Any ideas anyone ? I don't want to look at exspensive IC solutions, I feel there must be a way of using a few discrets to do the same job.
The supply voltage is from 0v to 17v, spikes can go up to 27v, then a zener will clamp it. I had been looking at using a transistor with a zener on the base to control the voltage for the PIC. I don't require much power to run the PIC, most of the other circuit will run off the high voltage rail of 9 to 17v.
I had seen some use of a mosfet, with the ability to turn off if the polls are reveresed thus protecting the circuit which I thought was good, as well as acting as a current limiting device.
Any ideas anyone ? I don't want to look at exspensive IC solutions, I feel there must be a way of using a few discrets to do the same job.