Discrete 1.5 to 1.35 voltage regulator

[tgq]

Hello
I am looking for a (simple) discrete LDO voltage regulator from 1.5 to 1.35V
Any help ?
Thanks

 

[Dominik Przyborowski]

Check here

 

[BradtheRad]

An led is its own voltage regulator. Use a potentiometer to 'dial' your desired reference voltage.

For the led, you can substitute a string of 2 or 3 diodes.

 

[Audioguru]

Diodes and LEDs are thermometers. Do you want the voltage to change when the temperature changes or as they warm up?
Transistors too. An IC voltage reference or regulator is designed to have no thermal problems.

 

[asdf44]

Shunt topology (less efficient): LMV431

 

[tgq]

Check here

thanks i know these integrted LDO
But my question was about discrete solution

 

[erikl]

Check **broken link removed**.

Or let me G00GLE that for you ;-)

 

[Dominik Przyborowski]

It will be very hard to find opamp working with 1.5V supply.

If You really need LDO working with 1.5V supply with 1.35V of output, You should use bandgap reference (~1.25V) and make an error amp on emitter degenerated NPN BJTs

 

[BigBoss]

If a proper transistor is biased and placed in series, its VCE(sat) will already be 0.1-0.25 V,I think it's enough ..
2 Resistors and 1 silicon transistor..

 

[erikl]

It will be very hard to find opamp working with 1.5V supply.

True, but there are some.

 

[tgq]

thanks i know these integrted LDO
But my question was about discrete solution

I know how to google and i didnt find a discrete solution
OPAMP is not discrete

 

[BradtheRad]

This is a simple series regulator.

The reference is an led and diode stacked inline. The diode is added to raise the reference by 0.6V. This is needed because 0.6V is dropped across the bias-emitter junction.



Values need to be adjusted to suit.