AME, Inc.

6

High Power BiPolar Linear LDO

AME1505

1. Output voltage adjustment

Like most regulators, the AME1505 regulates the out-

put by comparing the output voltage to an internally gen-

erated reference voltage. On the adjustable version, the

V

ADJ. The voltage ratio formed by R1 and R2 should be

set to conduct 10mA (minimum output load). The output

voltage is given by the following equation:

V

) + I

On fixed versions of AME1505, the voltage divider is

factory-preset internally.

n Application Description

R2

R1

2. Current limit protection

AME1505 is protected against overload conditions. Cur-

rent protection is triggered at typical 7.5A.

3. Stability and load regulation

AME1505 requires a capacitor from V

provide compensation feedback to the internal gain stage.

This is to ensure stability at the output terminal. Typi-

cally, a 10

µF tantalum or 50µF aluminum electrolytic is

sufficient.

(Note: It is important that the ESR for this capacitor does not ex-

ceed 0.5

Ω.)

The output capacitor dose not have a theoretical upper

limit and increasing its value will increase stability. C

OUT

= 100

µF or more is typical for high current regulator de-

sign.

For the adjustable version, the best load regulation is

accomplished when the top of the resistor divider (R1) is

connected directly to the output pin of the AME1505.

When so connected, R

ratio.

For fixed output versions, the top of R1 is internally

connected to the output. The ground pin can be connected

to low side of the load to eliminate ground loop errors.

V

R2

R1

) + I

ADJ

V

REF

I

ADJ

V

IN

V

OUT

R1

R2

C

1

SENSE

V

POWER

OUT

V

CONTROL

R1

R2

R

L

R

P

Parasitic

Line Resistance

Connect

R2 to load

(Connect R1 to case)

SENSE

ADJ

V

POWER

OUT

V

CONTROL

V

POWER

V

CONTROL