AP1519
300KHz, 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.1.0 Oct 5, 2004
1/9
Features
- Adjustable version output voltage range, 0.8V to
18V+4%
- 300KHz +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 Pb-Free 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 AP1519 is monolithic IC designed for a
step-down DC/DC converter, and own the ability of
driving a 2A load without additional transistor. It
saves board space. The external shutdown function
can be controlled by logic level and then come into
standby mode. The internal compensation makes
feedback control having 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 occurs and
V
FB
is down below 0.5V, the switching frequency
will be reduced. The AP1519 series operates at a
switching frequency of 300KHz thus allows 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 chips 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
AP1519
300KHz, 2A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Oct 5, 2004
2/9
Ordering Information
Package
S: SOP-8L
AP1519 X X
Packing
Blank : Tube
A : Taping
Block Diagram
Current
Source
bias
0.8V
Reference
2.5V
Regulator
300kHz
OSC.
Start
up
+
+
_
+
_
Thermal
Shutdown
Pre-driver
Comp
Comp
Gnd
Output
V
IN
SD
FB
220mV
200mV
2A
Switch
+
_
_
Amp
Comp
Frequecy
compen-
sation
AP1519
300KHz, 2A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Oct 5, 2004
3/9
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. I
LOAD
= 0.5A
Symbol
Parameter
Conditions
Min.
Typ.
Max.
Unit
-50
I
B
Feedback bias current
V
FB
=0.8V
(Adjustable version only)
-10
-100
nA
255 300 345
F
OSC
Oscillator
frequency
220 345
KHz
F
SCP
Oscillator frequency of
short circuit protect
When current limit occurred
and V
FB
< 0.5V, Ta=25
o
C
10 30 50 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
AP1519
300KHz, 2A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Oct 5, 2004
4/9
Electrical Characteristics (Continued)
Sym.
Parameter
Conditions
Typ.
Limit
Unit
FB
V
Output
Feedback
5V < V
IN
< 22V
0.2A < I
LOAD
< 2A
0.8
0.784/0.768
0.816/0.832
V
V
MIN
V
MAX
Efficiency
V
OUT
programmed for 3V
V
IN
= 12V, I
LOAD
=2A
75
%
Efficiency
V
OUT
programmed for 3.3V
V
IN
= 12V, I
LOAD
=2A
76
%
Efficiency
V
OUT
programmed for 5V
V
IN
= 12V, I
LOAD
=2A
81
%
AP1519
Efficiency
V
OUT
programmed for 12V
V
IN
= 16V, I
LOAD
= 2A
90
%
Specifications with boldface type are for full operating temperature range, the other type are for T
J
=25ēC.
AP1519
300KHz, 2A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Oct 5, 2004
5/9
Typical Application Circuit
(1) Normal Circuit
1
2
8
4
3
12V
DC Input
Cin
Capacitor
FB
SD
D1
Schottky
Diode
Vin
Gnd
Output
AP1519
Co
Capacitor
Inductor
L1
22uH
1V/2A
Output Load
Gnd
Gnd
Gnd
5
6
7
R1 250
R2 1K
Vout = V
FB
×
(1
+
R2
R1
)
(2) Delay Start Circuit
1
2
8
4
3
12V
DC Input
Cin
Capacitor
FB
SD
D1
Schottky
Diode
Vin
Gnd
Output
AP1519
Co
Capacitor
Inductor
L1
22uH
1V/2A
Output Load
Gnd
Gnd
Gnd
5
6
7
R1 250
R2 1K
C
DELAY
0.1uF
10K
R
DELAY
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