AP1513
PWM Control 2A Step-Down Converter
Features
- Input voltage: 3.6V to 18V.
- Output voltage: 0.8V to V
CC
.
- Duty ratio: 0% to 100% PWM control
- Oscillation frequency: 300KHz typ.
- Soft-start, Current limit, Enable function
- Thermal Shutdown function
- Built-in internal SW P-channel MOS
- SOP-8L
Pb-Free
Package.
General Description
AP1513 consists of step-down switching regulator
with PWM control. These devices include a reference
voltage source, oscillation circuit, error amplifier,
internal PMOS and etc.
AP1513 provides low-ripple power, high efficiency,
and excellent transient characteristics. The PWM
control circuit is able to vary the duty ratio linearly
from 0 up to 100%. This converter also contains an
error amplifier circuit as well as a soft-start circuit that
prevents overshoot at startup. An enable function,
an over current protect function and a short circuit
protect function are built inside, and when OCP or
SCP happens, the operation frequency will be
reduced from 300KHz to 30KHz. Also, an internal
compensation block is built in to minimum external
component count.
With the addition of an internal P-channel Power MOS,
a coil, capacitors, and a diode connected externally,
these ICs can function as step-down switching
regulators. They serve as ideal power supply units for
portable devices when coupled with the SOP–8L
mini-package, providing such outstanding features as
low current consumption. Since this converter can
accommodate an input voltage up to 18V, it is also
suitable for the operation via an AC adapter.
Applications
- PC Motherboard
- LCD Monitor
- Graphic Card
- DVD-Video Player
- Telecom Equipment
- ADSL Modem
- Printer and other Peripheral Equipment
- Microprocessor core supply
- Networking power supply
Pin Assignments
Pin Descriptions
Name
FB
Pin
Description
1 Feedback pin.
Power-off pin
H: Normal operation
(Step-down operation)
2
L: Step-down operation
stopped
(All circuits deactivated)
Add an external resistor to set
3
max output current.
4 IC power supply pin
Switch Pin. Connect external
inductor/diode here. Minimize
5、6
trace area at this pin to reduce
EMI.
7、8 GND Pin
FB 1
EN 2
AP1513
OCSET 3
V
CC
4
8
7
6
5
Vss
Vss
Output
Output
EN
OCSET
V
CC
Output
V
SS
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. 1.3 Nov 17, 2005
1/7
AP1513
PWM Control 2A Step-Down Converter
Electrical Characteristics
(V
IN
= 12V, T
a
=25
°C
, unless otherwise specified)
Symbol
V
IN
V
FB
I
FB
I
SW
I
SSS
Parameter
Input Voltage
Feedback Voltage
Feedback Bias Current
Switch Current
Current Consumption
During Power Off
Conditions
--
I
OUT
=0.1A
I
OUT
=0.1A
--
V
EN
=0V
V
IN
=5V~18V
I
OUT
=0.1 to 2A
Measure waveform at SW pin
Measure waveform at SW pin
Evaluate oscillation at SW pin
Evaluate oscillation stop at SW pin
--
--
--
--
V
IN
=5V, V
FB
=0V
V
IN
=12V, V
FB
=0V
V
IN
=12V, V
OUT
= 5V
I
OUT
=2A
Min.
3.6
0.784
-
2.5
-
-
-
240
10
2.0
-
-
-
75
0.3
-
-
-
-
Typ.
-
0.8
0.1
-
10
1
0.2
300
-
-
-
20
-10
90
2
110
70
92
65
Max.
18
0.816
0.5
-
-
2
0.5
400
-
-
0.8
-
-
105
5
150
100
-
-
o
Unit
V
V
µA
A
µA
%
%
KHz
KHz
V
µA
µA
µA
ms
mΩ
%
C/W
∆V
OUT
Line Regulation
/V
OUT
∆V
OUT
Load Regulation
/V
OUT
f
OSC
Oscillation Frequency
Frequency of Current Limit
f
OSC1
or Short Circuit Protect
V
SH
EN Pin Input Voltage
V
SL
EN Pin Input Leakage
I
SH
Current
I
SL
I
OCSET
OCSET Pin Bias Current
T
SS
Soft-Start Time
R
DSON
Internal MOSFET Rdson
EFFI
θ
JA
Efficiency
Thermal Resistance
Junction-to-Ambient
Typical Application Circuit
V
IN
R
OCSET
C
OCSET
3K
Option
C
IN
470uF
CVcc
0.1uF
R
EN
100K
C
EN
0.1uF
OCSET
EN
V
SS
D1
R
B
1.3K
Vcc
L1
Output
33uH
C
C
Optional
FB
R
A
6.8K
V
OUT
=5V/2A
AP1513
+
C
+
C
OUT
470uF
-
-
0.1uF
Note: V
OUT
= V
FB
x (1+R
A
/R
B
)
R
B
=0.7K~5K ohm
V
OUT
L1 Value
V
IN
=12V, I
MAX
=2A
2.5V
3.3V
22uH
27uH
5V
33uH
Anachip Corp.
www.anachip.com.tw
3/7
Rev. 1.3
Nov 17, 2005
Embedded System
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