Zxsc310 – Diodes ZXSC310 User Manual

Page 11

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Output Power Calculation

By making the above assumptions for inductance and
peak current the output power can be determined by:

Note:V

OUT

=output voltage + Schottky rectifier voltage

drop.

Where

T

OFF

≅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

S E M I C O N D U C T O R S

(

)

I

I

V

V

T

L

MIN

PK

OUT

IN

OFF

=

×

(

)

F

T

T

ON

OFF

=

+

1

I

I

I

AV

PK

MIN

=

+

2

(

)

T

T

V

V

V

ON

OFF

OUT

IN

IN

=

P

V

V

I

T

T

T

OUT

OUT

IN

AV

OFF

ON

OFF

=

Ч

Ч

+

(

)

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