ACT4528

Innovative Power

TM

- 8 -

www.active-semi.com

Copyright

©

2

0

1

5

-2017 Active-Semi, Inc.

Rev 2, 06-Jan-2016

APPLICATIONS INFORMATION

Current Sense Resistor

The traces leading to and from the sense resistor

can be significant error sources. With small value

sense resistors, trace resistance shared with the

load

can

cause

significant

errors.

It

is

recommended to connect the sense resistor pads

directly to the CSP and CSN pins using

“

K

e

l

v

i

n

”

o

r

“

4

-wire

”

c

o

n

n

e

c

t

i

o

n

t

e

c

h

n

i

q

u

e

s

a

s

s

h

o

w

n

b

e

l

o

w

.

Current Limit Setting

If output current hits

current limit, output voltage

drops to keep the current to a constant value.

The following equation calculates the constant

current limit.

Where Rcs is current sense resistor.

P

C

B

L

o

a

d

T

r

a

c

e

K

e

v

i

n

S

e

n

s

e

T

r

a

c

e

s

S

e

n

s

e

R

e

s

i

s

t

o

r

)

(

66

)

(





m

Rcs

mV

A

ILimit

(6)