Revision 1.8

14 - 20

AS3833

Datasheet - D e t a i l e d D e s c r i p t i o n

8.4.1

Setting the output voltage

Figure 16. Vout setting

According to the requirements of the LED strings, the output voltage Vout is adjusted by the internal power supply feedback

between:

and

Once Vout_min and Vout_max is known the external resistors can be caluclated:

Note:

The overall resistance should be in the range of 100k

Ω to 200kΩ to avoid any noise issues. Keep FB-line as short as possible.

V

OUTmin

V

R

fb

1

R

fb

2

----------

+









=

V

OUTmax

V

R

fb

1

R

fb

2

----------

+









255

µA R

fb

1

⋅

+

=

R

fb

1

V

OUTmax

V

OUTmin

–

(

)

255

µA

-------------------------------------------------------

=

(EQ 7)

R

fb

2

V

V

OUTmin

V

fb

–

(

)

----------------------------------------

=

(EQ 8)