Voltage regulation

[personman]

Dave,

I would love to see a blog on voltage regulation.  Methods, set ups, and appropriate choice per application including if/when no regulation is required.

For instance cap selection for say a 7805, when are zener diodes appropriate/not appropriate, other methods, ect.

Love the blog, I look forward to each release.

Thank you for your time. 

[djsb]

Hi,
I've had problems before with a regulator oscillating because of (my) poor PCB layout and also incorrect decoupling. I t would be nice to have some tips on this.
Also how do you design a power supply WITHOUT a regulator i.e for a high powered audio amplifier.
Any thoughts.

David.

[gbowne1]

This would be a good point to talk about good and bad PCB design.  Everyone could learn a few things from a nice blog on PCB design tips.  I also could benefit from one about Voltage Regulation because that's been one of my demons too.  I've too often not had the right part in hand when I really needed a better Voltage Regulator.

I have used the 7805 and 7809 with pretty good success.

Greg

[Simon]

with linear regulators like the 7805 you want input and output decoupling capacitors as close to the regulator as possible, not much mystery to it

[Neilm]

For tips on how to layout PCBs go to http://www.compliance-club.com/ and look for past articles by Keith Armstrong. This is mostly aimed for EMC compliance and high speed signals but the basics are there.

Neil

[DJPhil]

I know this thread has been dead a while, but I found a resource I thought might help if someone searches for it later on.

NEC has an excellent usage manual for 3 terminal regulators that I stumbled on looking for a datasheet.

Here's a copy of the table of contents to help show what it covers.

1. INTRODUCTION
2. BASIC STRUCTURE OF A POWER SUPPLY IC
   2.1 Structure of a Bipolar IC
   2.2 About Power Supply IC Equivalent Circuits
3. BASIC CIRCUITS OF A POWER SUPPLY IC
   3.1 Basic Circuits
   3.2 Operating Principles of Adjustable Output Types
   3.3 Operating Principles of Low Saturation Types
4. POWER SUPPLY IC APPLICATION CIRCUITS
   4.1 Typical Circuit Connection
   4.2 Application Circuit Set
5. PRECAUTIONS ON APPLICATION
   5.1 Shorting Input Pins and Ground Pins
   5.2 Floating Ground Pins
   5.3 Applying Transient Voltage to Input Pins
   5.4 Reverse Bias Between Output Pin and GND Pin
   5.5 Precautions Related to Low Saturation Types
   5.6 Thinking on Various Protection Circuits
6. POWER SUPPLY IC DATA SHEET APPEARANCE AND DESIGN METHODS
   6.1 Absolute Maximum Ratings
   6.2 Recommended Operating Conditions
   6.3 Electrical Specifications
   6.4 Design Methods

I know it doesn't really deal with the primary issue in this thread (seems to be pcb layout and decoupling), but perhaps someone will find it useful.