# ADM1270 - High voltage input protection device as current limiter

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
Hi,

do you guys know how to use this IC ADM1270 as current limiter?
i need this IC to limit current to 9A

thanks guy

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#### crutschow

Joined Mar 14, 2008
34,442
Suggest you read pages 15, 16, and 17 of the data sheet to learn how to connect it as a current limiter.
If you have any questions after that, get back with us and we'll try to answer them.

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
from what i understand Rsense (connected to Vcc/sense+ and sense - ) is used to limit the current....

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
from what i understand Rsense (connected to Vcc/sense+ and sense - ) is used to limit the current....
i roughly know how to connect as a current limiter but how to compute the value for Rsense?

#### crutschow

Joined Mar 14, 2008
34,442
i roughly know how to connect as a current limiter but how to compute the value for Rsense?
Did you read the section titled "SETTING THE CURRENT LIMIT (ISET)" on page 16?
For example, if you use the default current sense voltage limit (Vlim) of 50mV, then you would need a Rsense of 50mV / 9A = 5.55mΩ.
You can vary Vlim from 12.5 mV to 62.5 mV to adjust the limit current and compensate for the particular Rsense resistor value you may have.

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
Did you read the section titled "SETTING THE CURRENT LIMIT (ISET)" on page 16?
For example, if you use the default current sense voltage limit (Vlim) of 50mV, then you would need a Rsense of 50mV / 9A = 5.55mΩ.
You can vary Vlim from 12.5 mV to 62.5 mV to adjust the limit current and compensate for the particular Rsense resistor value you may have.
yeah i did, but still kinda confuse. Thanks alot, I will read the user guide again

#### crutschow

Joined Mar 14, 2008
34,442
What is this 9A powering?
What is the normal current?

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
What is this 9A powering?
What is the normal current?
What is this 9A powering?
is used to powering a DC motor

What is the normal current?
as in...??

#### #12

Joined Nov 30, 2010
18,224
What is this 9A powering?
is used to powering a DC motor

What is the normal current?
as in...??
What is the normal current the motor uses? Why is this particular motor unable to limit its own current? Billions of motors run properly if only given the right amount of voltage. What makes this one different?