MP2492 – 2A, 55V, 100kHz WITH PROGRAMMABLE OUTPUT CURRENT LIMIT

MP2492 Rev. 1.0

www.MonolithicPower.com

9

12/20/2010

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Output Current Sensing

The output current can be sensed through the

DC resistance (DCR) of the inductor, as shown

in Figure 3a.

For more accurate sensing, use a more

accurate sense resistor.

In Figure 3a, the output current limit is set as:

O U T

1 0 0 m V

R b

I

D C R

2 R a

R b

=×

+

Where DCR is the DC resistance of the inductor

winding.

In Figure 3a, it is desirable to keep

S

R a

R b

L 1

C

R a

R b

D C R

×

×=

+

For more accurate sensing, use a more

accurate sense resistor.

In Figure 3b, the output current limit is set as:

O U T

S E N S E

1 0 0 m V

I

R

=

Figure 3—Current Sensing Methods