FP7175

This datasheet contains new product information.

Feeling Technology reserves the rights to modify the product specification without notice.

No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.

Rev. 0.63

8/14

Average Current Control

The LED current is detected using a sense resistor at the CS pin. The feedback operates in a fast

current is programmed simply as:

)

Ω

(

R

V

25

.

0

=

)

A

(

I

CS

LED

Otherwise:

)

Ω

(

R

167

.

0

×

)

V

(

V

=

)

A

(

I

CS

DIM

LED

CS

LED

Current

Average Current =

0.25V

0.25V

t

t

The above equations are only valid for continuous conduction of the output inductor. It is a good

practice to design the inductor such that the switching ripple current in it is 25% of its average

peak-to-peak, full load, DC current.

GATE Output

The GATE output of the FP7175 is used to drive an external MOSFET. It is recommended that

the gate charge QG of the external MOSFET be less than 25nC for switching frequencies ≤100kHz and

less than 15nC for switching frequencies >100kHz.