AN3399

Voltage regulation circuit schematics

Doc ID 018824 Rev 2

5/24

1

Voltage regulation circuit schematics

1.1

Regulation with external PNP without current limitation

Figure 1.

Voltage regulation with external PNP

The Figure 1 is an example of recommended circuit for voltage regulation with external

transistor. As a reference voltage source was used 5V1 voltage regulator of L99PM62GXP.

Parameters of circuit at Figure 1 are:

●

Output voltage = 5.0 V

●

●

protection).

The output voltage is possible set by change of R1 and R2 value. In case of R3 = R4 the U3

is possible express from equation:

Important requirement is to ensure the voltage on OP_- and OP_+ inputs is bellow 3 V.

U

3

U

5V1

R

4

R

3

R

4

+

---------------------



R

1

R

2

+

R

2

--------------------- V



+

=