AS1374

Datasheet - Application In form atio n

www.austriamicrosystems.com/LDOs/AS1374

Revision 1.8

12 - 18

Figure 28. Steady State Heat Flow Equivalent Circuit

Total Thermal Path Resistance:

R

(EQ 6)

(EQ 7)

9.5 Explanation of Steady State Specifications

9.5.1 Line Regulation

Line regulation is defined as the change in output voltage when the input (or line) voltage is changed by a known quantity. It is a measure of the

regulator’s ability to maintain a constant output voltage when the input voltage changes. Line regulation is a measure of the DC open loop gain

of the error amplifier. More generally:

Line Regulation =

and is a pure number

(EQ 8)

available with numerous output voltage trim options.

Line Regulation =

% / V

(EQ 9)

9.5.2 Load Regulation

Load regulation is defined as the change of the output voltage when the load current is changed by a known quantity. It is a measure of the

regulator’s ability to maintain a constant output voltage when the load changes. Load regulation is a measure of the DC closed loop output

resistance of the regulator. More generally:

Load Regulation =

and is units of ohms (

)(EQ 10)

In practise, load regulation is referred to the regulator output voltage in terms of % / mA. This is particularly useful when the same regulator is

available with numerous output voltage trim options.

Load Regulation =

% / mA

(EQ 11)

Junction

Package

PCB/Heatsink

Ambient

Chip

Power

R

R

R

V

OUT

V

IN

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

V

OUT

V

IN

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

100

V

OUT

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



V

OUT

I

OUT

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

V

OUT

I

OUT

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

100

V

OUT

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

