Diode regulator VS IC regulator.

[Rembrant]

As the title suggests, I am interested in the differences between these two types of regulators.
I can see advantages to using a diode based regulator if high current is needed also if you don't have the 3v overhead an IC regulator would require. One disadvantage would be possible temp stability issues.

IC regulators can easily be used with a high power transistor if the extra current is required.

Aside from those things, I don't really have a grasp on the regulation properties of the two types.

There must be some inherent advantage with the IC regulators, because everyone seems to be using them.

[peranders]

Diode regulator, never heard of. Can you explain?

[mastodon]

Originally Posted by Rembrant

As the title suggests, I am interested in the differences between these two types of regulators.
I can see advantages to using a diode based regulator if high current is needed also if you don't have the 3v overhead an IC regulator would require. One disadvantage would be possible temp stability issues.

You mean a simple shunt regulator using zeners?

Anyway, concerning the voltage drop: note that you always need some drop just to maintain regulation.

[DF96]

A zener diode is a shunt regulator. It will need to consume a certain minimum current in order to regulate. There must be a resistor in series with the supply so that the current can drop the voltage. Shunt regulators waste power.

Most ICs are series regulators. They still waste power, but less than a shunt regulator. They are more complex, and may have a non-trivial output impedance which may or may not cause stability problems. They may be temperature-compensated so more stable than a simple shunt regulator.

[martin clark]

'non trivial output impedance' This is true. But the effective output impedance for simple shunt regulators, like zeners or diodes, is pretty horrific - at least two orders of magnitude worse than even the most basic simple 3-pin reg (in the audio band)

[twest820]

Originally Posted by Rembrant

I can see advantages to using a diode based regulator if high current is needed also if you don't have the 3v overhead an IC regulator would require.

3V implies a standard linear regulator with moderate ripple and zener regulation implies a low current load, in which case there are any number of low current LDOs that would work. Micrel's uCap line is a good starting point; relatively low cost, simple stablity requirements, good range of input and output voltages, and compact on the board.