AL1692

Document number: DS39008 Rev. 2 - 2

10 of 15

www.diodes.com

September 2017

© Diodes Incorporated

AL1692

Inductance Selection (L2)

In buck-boost structure, the peak current of the inductance can be calculated as below

_

0

_

2

sin( )

5

sin( )

2

sin( )

REF

PEAK

IN

RMS

IN

RMS

V

I

V

Rd

V

Vo



























Where,

’s RMS value

The AL1692 controls the system operating at boundary conduction mode which results in its operating frequency not being constant. To set the

_

_

2

2

2+

IN

RMS

O

PEAK

IN

RMS

O

MIN

VV

L

I

V

V

f







According to the Faraday

’s Law, the winding number of the inductance can be calculated by:

2

2

PEAK

L

em

LI

N

AB







Where,

_

_

3.3

0.33

10

6

REF

ON

MAX

RT

REF

C

t

V

uA

R









Where

’s reference.

Dimming Control

at the largest conduction angle, the device still has the adjustability to control the output current constant before COMP voltage is adjusted to the

maximum 4V, so for most of the dimmer, the output current is almost the same with the no dimmer condition at the largest conduction angle. If the

conduction angle is decreased, the COMP pin voltage will continue to increase quickly till to the maximum level (typical 4V), the device will output

resistor (R6).

can get the following equation:

__

_

()

2

I N

RMS

ON MAX

PEAK

DIM

V

Sin

t

I

L





