ZSLS7025 Datasheet

© 2016 Integrated Device Technology, Inc.

15

April 20, 2016

(

)

OFF

ON

t

t

1

f

+

=

(

)

CS

DS(ON)

L

IN_AVG

IN

1

RIPPLE

ON

R

R

R

I

V

)

L

(I

t

+

+

×

−

×

≈

(

)

AVG

_

IN

PEAK

_

IN

RIPPLE

I

I

2

I

−

×

=

(

)

IN

L

IN_AVG

D

OUT

1

RIPPLE

OFF

V

R

I

V

V

L

I

t

−

×

+

+

×

≈

η

1

V

V

1

R

I

D

R

I

P

OUT

IN

DS(ON)

2

IN_AVG

Q1

DS(ON)

2

IN_AVG

DISS

×













−

×

×

≈

×

×

≈

(8)

The ripple current in the inductor can be calculated with equation (9).

(9)

(10)

Where

in Ω

in Ω (see manufacturer's specifications)

(11)

Where

If not, the converter cannot output the required current.

The recommended switching frequency is 20kHz < f < 200kHz. Lower than 20KHz will cause audio noise of the

2.10

DC Power Loss

(12)

Where