Switching power supply design using PWM on uC 2

[tommyb82000]

All,

I am trying to design a buck and a boost regulator using the PWM capabilities of a uC. I have picked up several books but they seem to jump around quite a bit. Does any one have any useful resources (links, equations, experiences, etc.) that can help? The buck is to supply 3.3V at ~ 400 mA and the boost is to charge two 33 mF 16V caps to fire into solenoids. I have used OEM cap chargers before that charge up to 1.5kV extremely fast, so I think I coud make one to go from 5.5V to 16V pretty darn fast as well. Your input is greatly appreciated.

 

[Madcow]

Most micro manufacturers have app notes for this.
Alot depends on the application. If you dont need
tight regulation or current limit you can just
set the duty cycle and let it run open loop.
If you need more then start with some of these sites.

http://techtrain.microchip.com/webseminars/Main.aspx

click on the archived seminars. some nice intro stuff.

http://www.smpstech.com/

This site is good for power supply design.

Other sites are:
TI
National
Motorola
Fairchild
IR
ST
Infineon

and just about any major semiconductor manufacture.

 

[OperaHouse]

One of the more interesting designs I have seen was in a wide voltage range device. They monitored the voltage with the uP and adjusted the PWM time on of the port they drove the relay with. Less parts and no heat compared to other designs!