Diodes AP1509 - Manual (Page 2)

AP1509
150KHz, 2A PWM BUCK DC/DC CONVERTER
AP1509
Document number: DS31016 Rev. 4 - 2
2 of 13
www.diodes.com
June 2010
© Diodes Incorporated
Typical Application Circuit
(1) Fixed Type Circuit
1 2
8 4
3
12V
DC Input
C
IN
Capacitor
FB
SD
D1
Schottky Diode
V IN
GND
Output AP1509-
33
Co
Capacitor
Inductor
L1
47uH
3.3V/2A
Output Load
GND GND GND
5 6 7
(2) Adjustable Type Circuit
1 2
8 4
3
12V
DC Input
C
IN
Capacitor
FB
SD
D1
Schottky
Diode
V
IN
GND
Output
AP1509
Co
Capacitor
Inductor
L1
39uH
2.5V/2A
Output Load
GND GND GND
5 6 7
R1 1K R2 1K
V
OUT
= V
FB
×
(1 +
R2
R1
)
V
FB
= 1.23V
R2 = 1K ~ 3K
(3) Delay Start Circuit
1 2
8 4
3
12V
DC Input
C
IN
Capacitor
FB
SD
D1
Schottky
Diode
V
IN
GND
Output
AP1509
Co
Capacitor
Inductor
L1
39uH
2.5V/2A
Output Load
GND GND GND
5 6 7
R1 1K R2 1K
C
DELAY
0.1uF
10K
R
DELAY