Output Power Calculation

By making the above assumptions for inductance and

peak current the output power can be determined by:

drop.

Where

≅1.7us (internally set by ZXSC310)

and

and

Where

Operating frequency can be derived by:

Capacitor selection

For pulsed operation, as in the maximum battery life

solution, no capacitors are required at the output to the

LED. For rectified operation, as in the maximum

brightness solution, a small value ceramic capacitor is

required, typically 2.2uF.

Generally an input capacitor is not required, but a small

ceramic capacitor may be added to aid EMC, typically

470nF to 1uF.

(notes)

ZXSC310

ISSUE 3 - SEPTEMBER 2007

11

SEMICO NDUC TORS

()

II

VV

T

L

MIN

PK

OUT

IN

OFF

=−

−×

()

F

TT

ON

OFF

=

+

1

I

II

AV

PK

MIN

=

+

2

()

T

TV

V

V

ON

OFF

OUT

IN

IN

=

−

PV

V

I

T

TT

OUT

OUT

IN

AV

OFF

ON

OFF

=−

×

×

+

()