Anachip AP1503SLA 300khz, 2.5a pwm buck dc/dc converter Datasheet

AP1503
300Khz, 2.5A PWM Buck DC/DC Converter
„ Features
„ General Description
- Output voltage: 3.3V
- 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: 2.5A
- SOP-7L packages
- Low power standby mode
- Built-in switching transistor on chip
The AP1503 series are monolithic ICs designed for
step-down DC/DC converters, and own the ability
of driving a 2.5A load without additional transistor
components. 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 external compensation makes feedback
control have good line and load regulation.
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. The AP1503 series operates at a
switching frequency of 300KHz thus allowing
smaller sized filter components than what would be
needed with lower frequency switching regulators.
Other features include a guaranteed +2% 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. The packages are available in a standard
SOP-7 lead package.
„ Applications
- Simple High-efficiency step-down regulator
- On-card switching regulators
- Positive to negative converter
- DSL Modems
- Portable Computers
- Regulated Wall Adapters
- Distributed Power
„ Pin Assignment
„ Pin Descriptions
Name
SOP7 with Heat Sink
VIN
1
VB
2
SD
3
FB
4
7
VO
6
GND
VIN
Operating voltage input
VB
Boost pin
SD
ON/OFF Shutdown
FB
Output voltage feedback control
COMP
5
COMP
Description
GND
VO
Compensation pin
Ground
Switching output
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 Sep. 29, 2004
1/5
AP1503
300Khz, 2.5A PWM Buck DC/DC Converter
„ Ordering Information
AP1503 XX X X X
Output version
-33 : 3.3V
Package
Lead Free
Packing
S : SOP-7L
Blank : Normal
L : Lead Free Package
Blank : Tube
A : Taping
„ Block Diagram
SD
VIN
200mV
Current
Source
bias
1.235V
Reference
2.5V
Regulator
220mV
Start
up
+
Comp
_
_
Comp
+
VB
+
Amp
_
Frequecy
compensation
_
FB
Comp
+
Pre-driver
3A
Switch
VO
300kHz
OSC.
Thermal
Shutdown
GND
COMP
Anachip Corp.
www.anachip.com.tw
Rev 1.0 Sep. 29, 2004
2/5
AP1503
300Khz, 2.5A PWM Buck DC/DC Converter
„ Absolute Maximum Ratings
Symbol
VCC
VSD
VFB
VOUT
PD
TST
TOP
VOP
Parameter
Supply Voltage
ON/OFF Pin input voltage
Feedback Pin voltage
Output voltage to Ground
Power dissipation
Storage temperature
Operating temperature
Operating voltage
Rating
+26
-0.3 to +25
-0.3 to +25
-1
Internally limited
-65 to +150
-40 to +125
+7 to +40
Unit
V
V
V
V
W
o
C
o
C
V
„ Electrical Characteristics (All Output Voltage Versions)
Unless otherwise specified, VIN=12V for 3.3V, 5V, ILOAD = 0.5A
Symbol
Parameter
FOSC
Oscillator frequency
VSAT
Saturation voltage
DC
Max. Duty Cycle (ON)
Min. Duty cycle (OFF)
ICL
Current limit
IL
VC
VB
IB
IQ
ISTBY
VIL
VIH
IH
IL
ΘJC
ΘJA
Output
leakage
Output = -1 current
Output = 0
Conditions
Min.
Typ.
Max.
255
300
345
230
ISW=2A
VB=VIN+2.5V.
VFB=0V force driver on
VFB=6V force driver off
Peak current
No outside circuit
VFB=0 force driver on
no outside circuit
VFB=6V force driver off
VIN=24V
COMP Min SW threshold Duty Cycle=0%,FB=3.5V
2A ISW threshold
Min VB above switch
ISW=2A
ISW=1A
Boost current
ISW=2A
Quiescent Current
VFB=6 force driver off
Standby Quiescent
ON/OFF pin=5V
Current
VIN=24V
Low (regulator ON)
ON/OFF pin logic input
threshold voltage
High (regulator OFF)
ON/OFF pin logic input
VLOGIC=2.5V (OFF)
current
ON/OFF pin input current VLOGIC=0.5V (ON)
Thermal Resistance
SOP-7L Junction to case
Thermal Resistance
Junction to
With copper area of
SOP-7L
2
ambient
approximately 0.5 in
Anachip Corp.
www.anachip.com.tw
0.4
360
0.5
0.6
Unit
KHz
V
90
0
3
3.25
0.04
0.8
2.6
120
130
5
80
2.0
1.3
%
3.5
A
4
-1
uA
-1
mA
V
3
V
mA
140
10
150
200
0.6
mA
uA
V
-0.1
-1
uA
20
o
50
o
C/W
C/W
Rev 1.0 Sep. 29, 2004
3/5
AP1503
300Khz, 2.5A PWM Buck DC/DC Converter
„ Electrical Characteristics (Continued)
Symbol
Parameter
Conditions
Typ.
Limit
Unit
VOUT
Output voltage
7V < VIN < 24V
0.2A < ILOAD < 2.5A
3.3
3.23/3.2
3.37/3.4
V
VMIN
VMAX
η
Efficiency
VIN = 12V, ILOAD=2A
79
AP1503-3.3V
%
Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC.
„ Typical Application Circuit
FB
7V
DC Input
Vin
AP1503
-33
1
5
3
Cin
Capacitor
VB
2
4
SD
7
CB
VO
D2
3.3V/2.5A
Schottky Diode
Output Load
L1
Inductor
6
COMP GND
D1
Schottky Diode
Co
Capacitor
CC
Anachip Corp.
www.anachip.com.tw
Rev 1.0 Sep. 29, 2004
4/5
AP1503
300Khz, 2.5A PWM Buck DC/DC Converter
„
Marking Information
( Top View )
7
5
Logo
Output Type
33 : 3.3V
AP1503 XX
Blank: normal
L: Lead Free Package
YY WW X X
1
ID code: internal
Xth week: 01~52
Year: "01" = 2001
"02" = 2002
4
~
„ Package Information
Package Type: SOP-7L
C2
C3
B1 B2
A
E
C1
C
e
D
β
F
Symbol
A
B1
B2
C
C1
C2
C3
D
E
e
F
β
Dimensions In Millimeters
Min.
5.79
3.83
3.78
4.80
1.57
0.32
1.17
0.19
0.48
1.35
Nom.
5.99
3.91
3.86
4.87
1.67
0.4
1.27
0.22
1.04REF
0.68
1.45
7o
Dimensions In Inches
Max.
6.19
3.99
3.94
4.94
1.77
0.48
1.37
0.25
Min.
0.228
0.151
0.149
0.189
0.062
0.013
0.046
0.007
0.88
1.55
0.019
0.053
Anachip Corp.
www.anachip.com.tw
Nom.
0.236
0.154
0.152
0.192
0.066
0.016
0.050
0.009
0.041REF
0.027
0.057
7o
Max.
0.244
0.157
0.155
0.194
0.070
0.019
0.054
0.010
0.035
0.061
Rev 1.0 Sep. 29, 2004
5/5
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