AIC2511
3A STEP-DOWN PWM CONVERTER
FEATURES
Operating Input Voltage From 4.5V to 24V
3.3V, 5V, 12V and Adjustable Output Version
Adjustable Version Output Voltage Range,
1.2V to 24V
±
4% max Over Line and Load
Regulation
Available in TO-263-5, TO-220-5, TO-220B
and TO-252-5 Package
Requires Only 4 External Components.
150KHz Fixed Constant Frequency
Low Power Standby Mode, I
Q
Typically 80µA
TTL Shutdown Capability.
Current Limit
Protection.
and
Thermal
Shutdown
GENERAL DESCRIPTION
The AIC2511 series are step-down monolithic
PWM converters for delivering 3A at fixed
voltages of 3.3V, 5.0V, 12V and using an
external divider to adjust output voltage from
1.2V to 24V with excellent line and load
regulation.
Switching frequency up to 150KHz is achievable
thus allowing smaller-sized filter components.
Internal current limit and thermal shutdown
circuits provide protection from overloads. The
internal
voltage
precise
accuracy
reference
and
fast
combined
load
with
voltage feedback loop provides optimum output
transient
response.
3A Guaranteed Output Load Current
APPLICATIONS
Fixed Voltage power supply for LCD Monitor
and LCD TV
On-Card Switching regulators
Simple High Efficiency Step-down regulator
TYPICAL APPLICATION CIRCUIT
V
IN
+
C1
5
4
FB
D1
AIC2511
1
IN
OUT
2
L1
C2
+
R1
V
OUT
CF
C1: electrolyte capacitor 470uF
C2: electrolyte capacitor 220uF
CF:refer to table1
D1: SK54
L1:33uH
Analog Integrations Corporation
FFO/NO
GND
3
R2
R1 short, R2 and CF open for fixed version
3A1, No.1 Li-Hsin Rd. I, Science Park, Hsinchu 300, Taiwan
TEL: 886-3-5772500
FAX: 886-3-5772510 www.analog.com.tw
DS-2511G-01 092408
1
AIC2511
ABSOLUTE MAXIMUM RATINGS
Supply Voltage
FB, ON/OFF Pin Input Voltage
Operating Temperature Range
Storage Temperature Range
Junction Temperature
Lead Temperature (Soldering 10sec.)
Thermal Resistance Junction to Case
TO-263-5, TO-220-5, TO-220B
TO-252-5
Thermal Resistance Junction to Ambient
(Assume no ambient airflow, no heatsink)
TO-263-5
TO-220-5, TO-220B
TO-252-5
24V
-0.3V to 24V
-40°C ~ 85°C
-65°C ~ 150°C
125°C
260°C
3°C /W
12.5°C /W
60°C /W
50°C /W
100°C /W
Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
3
AIC2511
ELECTRICAL CHARACTERISTICS
PARAMETER
Input Voltage
Fixed Output Voltage
AIC2511-33 (V
IN
> 4.75V)
AIC2511-50 (V
IN
> 7.0V)
AIC2511-12 (V
IN
> 15V)
FB Reference Voltage
Saturation Voltage
Output Voltage Regulation
Quiescent Current
Shutdown Quiescent Current
FB bias current
Output leakage current
Logic Input High
Logic Input Low
Oscillator Frequency
Output Current Limit
Maximum Duty Cycle
Minimum Duty Cycle
Efficiency
Vo=5V, Io=3A
Internal switch off
ON/OFF= 5V (OFF)
V
FB
=1.3
Vout=-0.9
(Regulator OFF)
(Regulator ON)
130
3.6
100
0
80
150
2.0
0.6
180
5.5
5
80
10
2
(T
A
=25°C, V
IN
=12V for the 3.3V, 5V and
°
Adjustable version and V
IN
=24V for the 12V version.) (Note1)
TEST CONDITIONS
MIN.
4.5
3.168
4.800
11.52
1.193
1.2
TYP.
MAX.
24
3.432
5.200
12.48
1.267
1.4
4
10
200
50
30
UNIT
V
V
V
V
V
V
%
mA
µA
nA
mA
V
V
KHz
A
%
%
%
Note 1:
Specifications are production tested at T
A
=25°C. Specifications over the -40°C to 85°C operating
temperature range are assured by design, characterization and correlation with Statistical Quality
Controls (SQC).
4
AIC2511
TYPICAL PERFORMANCE CHARACTERISTICS
85
80
75
70
65
90
85
VOUT=3.3V version
80
75
70
VOUT=5.0V version
Efficiency (%)
55
50
45
40
35
30
25
20
10
100
1000
Efficiency (%)
60
65
60
55
50
45
40
35
Vin=5V
Vin=12V
Vin=18V
Vin=24V
Vin=12V
Vin=18V
Vin=24V
30
25
10
100
1000
Load current (mA)
Load current (mA)
Fig.1 3.3V version efficiency
95
90
85
80
90
85
Fig.2 5V version efficiency
VOUT=12.0V version
Case Tempearature ( C)
o
80
75
70
65
60
55
50
45
40
35
30
4
8
12
16
Vout=12V
Vout=5.0V
Efficiency (%)
75
70
65
60
55
50
45
10
100
1000
Vout=3.3V
Vin=18V
Vin=24V
I
OUT
=3A
TO-263-5
20
24
Load current (mA)
Input Voltage (V)
Fig.3 12V version efficiency
200
190
Fig.4 Case temperature vs. input voltage
6.8
6.4
6.0
Switching Frequency (kHz)
180
Current Limit (A)
170
160
150
140
130
120
110
100
-60
-40
-20
0
20
o
5.6
5.2
4.8
4.4
4.0
3.6
3.2
40
60
80
100
2.8
-60
-40
-20
0
20
40
60
80
100
T
J
( C)
Fig.5 Switching Frequency vs. Temperature
Current Limit vs. Temperature
Fig.6 Current Limit vs. Temperature
5
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