AP1509
150KHz, 2A PWM Buck DC/DC Converter
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev. 0.1 Nov 27, 2003
1/8
Features
- Output voltage: 3.3V, 5V, 12V and adjustable
output version
- Adjustable version output voltage range, 1.23V to
18V+4%
- 150KHz +15% fixed switching frequency
- Voltage mode non-synchronous PWM control
- Thermal-shutdown and current-limit protection
- ON/OFF shutdown control input
- Operating voltage can be up to 22V
- Output load current: 2A
- SOP-8L packages
- Low power standby mode
- Built-in switching transistor on chip
Applications
- Simple High-efficiency step-down regulator
- On-card switching regulators
- Positive to negative converter
General Description
The AP1509 series are monolithic IC designed for a
step-down DC/DC converter, and own the ability of
driving a 2A load without additional transistor
component. Due to reducing the number of external
component, the board space can be saved easily.
The external shutdown function can be controlled
by logic level and then come into standby mode.
The internal compensation makes feedback control
have good line and load regulation without external
design. Regarding protected function, thermal
shutdown is to prevent over temperature operating
from damage, and current limit is against over
current operating of the output switch. If current
limit function occurred and V
FB
is down to 0.5V
below, the switching frequency will be reduced.
The AP1509 series operates at a switching
frequency of 150KHz thus allowing smaller sized
filter components than what would be needed with
lower frequency switching regulators. Other
features include a guaranteed +4% tolerance on
output voltage under specified input voltage and
output load conditions, and +15% on the oscillator
frequency. The output version included fixed 3.3V,
5V, 12V, and an adjustable type. The packages are
available in a standard 8-lead SOP-8 package.
Pin Assignments
Output
FB
SD
GND
GND
GND
GND
1
3
2
4
8
6
7
5
SOP-8L
(Top View)
V
IN
Pin Descriptions
Name
Description
V
IN
Operating voltage input
Output Switching
output
GND Ground
FB Output
voltage
feedback
control
SD ON/OFF
Shutdown
AP1509
150KHz, 2A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.0.1 Nov 27, 2003
2/8
Ordering Information
Package
S: SOP-8L
Output version
AP1509 XX X X X
Packing
Blank : Tube
A : Taping
Blank : Adjustable
-33 : 3.3V
-50 : 5.0V
-12 : 12V
Lead Free
Blank : Normal
L : Lead Free Package
Block Diagram
Current
Source
bias
1.235V
Reference
2.5V
Regulator
150kHz
OSC.
Start
up
+
+
_
+
_
Thermal
Limit
Pre-driver
Comp
Comp
Gnd
Output
V
IN
SD
FB
220mV
200mV
2A
Switch
+
_
_
Amp
Comp
Frequecy
compen-
sation
AP1509
150KHz, 2A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.0.1 Nov 27, 2003
3/8
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
V
CC
Supply
Voltage
+24
V
V
SD
ON/OFF Pin input voltage
-0.3 to +18
V
V
FB
Feedback Pin voltage
-0.3 to +18
V
V
OUT
Output voltage to Ground
-1
V
P
D
Power dissipation
Internally limited
W
T
ST
Storage temperature
-65 to +150
o
C
T
OP
Operating temperature
-40 to +125
o
C
V
OP
Operating voltage
+4.5 to +22
V
Electrical Characteristics (All Output Voltage Versions)
Unless otherwise specified, V
IN
=12V for 3.3V, 5V, adjustable version and V
IN
=18V for the 12V version. I
LOAD
= 0.5A
Symbol
Parameter
Conditions
Min.
Typ.
Max.
Unit
-50
I
B
Feedback bias current
V
FB
=1.3V
(Adjustable version only)
-10
-100
nA
127 150 173
F
OSC
Oscillator
frequency
110 173
KHz
F
SCP
Oscillator frequency of
short circuit protect
When current limit occurred
and V
FB
< 0.5V, Ta=25
o
C
5 15 25
KHz
1.4
V
SAT
Saturation
voltage
I
OUT
=2A
No outside circuit
V
FB
=0V force driver on
1.25
1.5
V
Max. Duty Cycle (ON)
V
FB
=0V force driver on
100
DC
Min. Duty Cycle (OFF)
V
FB
=12V force driver off
0
%
I
CL
Current
limit
Peak current
No outside circuit
V
FB
=0V force driver on
3 A
Output = 0
No outside circuit
V
FB
=12V force driver off
-200
uA
I
L
Output = -1
Output
leakage
current
V
IN
=22V
-5 mA
I
Q
Quiescent
Current
V
FB
=12V force driver off
5
10
mA
150
I
STBY
Standby Quiescent
Current
ON/OFF pin=5V
V
IN
=22V
70
200
uA
V
IL
Low (regulator ON)
-
0.6
V
IH
ON/OFF pin logic input
threshold voltage
High (regulator OFF)
2.0
1.3
-
V
I
H
ON/OFF pin logic input
current
V
LOGIC
=2.5V (OFF)
-0.01
I
L
ON/OFF pin input current V
LOGIC
=0.5V (ON)
-0.1
-1
uA
JC
Thermal Resistance
SOP-8L
Junction to
case
15
o
C/W
JA
Thermal Resistance
With copper area of
approximately 3 in
2
SOP-8L
Junction to
ambient
70
o
C/W
AP1509
150KHz, 2A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.0.1 Nov 27, 2003
4/8
Electrical Characteristics (Continued)
Symbol
Parameter
Conditions
Typ.
Limit
Unit
FB
V
Output
Feedback
4.5V < V
IN
< 22V
0.2A < I
LOAD
< 2A
V
OUT
programmed for
3V
1.23
1.193/1.18
1.267/1.28
V
V
MIN
V
MAX
AP1509-ADJ
Efficiency V
IN
= 12V, I
LOAD
=2A 76
%
OUT
V
Output voltage
4.75V < V
IN
< 22V
0.2A < I
LOAD
< 2A
3.3
3.168/3.135
3.432/3.465
V
V
MIN
V
MAX
AP1509-3.3V
Efficiency V
IN
= 12V, I
LOAD
=2A 78
%
OUT
V
Output voltage
7V < V
IN
< 22V
0.2A < I
LOAD
< 2A
5
4.8/4.75
5.2/5.25
V
V
MIN
V
MAX
AP1509-5V
Efficiency V
IN
= 12V, I
LOAD
=2A 83
%
OUT
V
Output voltage
15V < V
IN
< 22V
0.2A < I
LOAD
< 2A
12
11.52/11.4
12.48/12.6
V
V
MIN
V
MAX
AP1509-12V
Efficiency V
IN
= 15V, I
LOAD
= 2A
90
%
Specifications with boldface type are for full operating temperature range, the other type are for T
J
=25ºC.
Typical Application Circuit
1
2
8
4
3
12V
DC Input
C
in
Capacitor
FB
SD
D1
Schottky Diode
Vin
Gnd
Output
AP1509
-33
Co
Capacitor
Inductor
L1
3.3V/2A
Output Load
Gnd
Gnd
Gnd
5
6
7
AP1509
150KHz, 2A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.0.1 Nov 27, 2003
5/8
Typical Performance Characteristics
AP1509 Efficiency v.s. Temperature
(Vin=12V,Vout=5V,Io=2A)
75
76
77
78
79
80
81
82
83
84
85
86
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (°C)
Efficiency (%)
AP1509 Efficiency v.s. Temperature
(Vin=12V,Vout=3.3V,Io=2A)
73
74
75
76
77
78
79
80
81
-50 -30 -10 10 30
50 70 90 110 130 150
Temperature (TA) (°C)
Efficiency (%)
AP1509 Saturation Voltage v.s. Temperature
(Vcc=12V,Vfb=0V,VSD=0)
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
-50
-25
0
25
50
75
100
125
Temperature (TA)(°C)
Saturation Voltage (V)
2A
1A
0.5A
AP1509 Switch Current Limit v.s. Temperature
(Vcc=12V,Vfb=0V)
3
3.5
4
4.5
5
5.5
-50
-30
-10
10
30
50
70
90
Temperature (TA) (°C)
Switch Current Limit (A)
AP1509 Supply Current v.s. Temperature
(Vcc=12V , No Load ,Von/off =0V(Switch ON) ,Von/off =5V(Switch OFF))
5
6
7
8
9
10
11
12
13
14
15
-50 -30 -10 10
30
50
70
90 110 130 150
Temperature (TA) (°C)
Supply Current (mA)
Switch ON
30
35
40
45
50
55
60
-50 -30 -10 10
30
50
70
90 110 130 150
Temperature (TA) (°C)
Supply Current (uA)
Switch OFF
PDF 
ZIP