TIGER ELECTRONIC CO.,LTD
LM2576 Series
Description
The LM2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching
regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V,
5V, 12V, 15V, and an adjustable output versions. Requiring a minimum number of external components, these regulators are simple to
use and include internal frequency compensation and a fixed-frequency oscillator. The LM2576 series offers a
high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in some
cases no heat sink is required. A standard series of inductors optimized for use with the LM2576 are available from several different
manufacturers. This feature greatly simplifies the design of switch-mode power supplies. Other features include a guaranteed ± 4%
tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External
shutdown is included, featuring 50µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as
thermal shutdown for full protection under fault conditions.
Note:
Features
•
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•
•
•
•
•
•
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Applications
•
•
•
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3.3V, 5V, 12V, 15V, and adjustable output versions
Adjustable version output voltage range
1.23V to 37V (57V for HV version) ± 4% max over line
and load conditions
Guaranteed 3A output current
Wide input voltage range, 40V up to 60V for HV
version
Requires only 4 external components
52 kHz fixed frequency oscillator
TTL shutdown capability, low power standby mode
High efficiency
Uses readily available standard inductors
Thermal shutdown and current limit protection
Simple high-efficiency step-down (buck) regulator
Efficient pre-regulator for linear regulators
On-card switching regulators
Positive to negative converter (Buck-Boost)
Typical application
Figure 1.(Fixed Output Voltage Versions)
7V - 40V
(60V for HV)
UNREGULATED
DC INPUT
+V
IN
1
LM2576/
LM2576HV-
5.0
3
+
GND
C
IN
FEEDBACK
4
L1
OUTPUT
2
100
H
5 ON/OFF
D1
1N5822
+
C
OUT
1000
F
+5V
REGULATED
OUTPUT
3A
LOAD
TIGER ELECTRONICS CO.,LTD
1
LM2576 Series
Block Diagram
V
IN
UNREGULATED
DC INPUT
C
IN
FEED-
BACK
1
+
INTERNAL
REGULATOR
ON/OFF
5
ON/OFF
4
R2
FIXED GAIN
ERROR AMP
R1
1.0k
+
-
COMPARATOR
DRIVER
3 AMP
SWITCH
OUTPUT
2
3
+
-
L1
V
OUT
+
D1
C
OUT
1.23V
52kHZ
BAND-GAP
REFERENCE OSCILLATOR
RESET
THERMAL
SHUTDOWN
CURRENT
LIMIT
GND
L
O
A
D
3.3V, R2 =1.7K
5V, R2 = 3.1K
12V, R2 = 8.84K
15V, R2 =11.3K
For ADJ, Version
R1 = Open, R2 =0Ω
Ordering information
Temperature
Range
-25°C
≤
T
A
≤
75°C
Output Voltage, V
3.3
LM2576SX-3.3
5.0
LM2576SX-5.0
12
LM2576SX-12
15
LM2576SX-15
ADJ
LM2576SX-ADJ
TO-263
Package Type
LM2576HVS-3.3 LM2576HVS-5.0 LM2576HVS-12 LM2576HVS-15 LM2576HVS-ADJ
LM2576T-3.3
LM2576T-5.0
LM2576T-12
LM2576T-15
LM2576T-ADJ
TO-220
LM2576HVT-3.3 LM2576HVT-5.0 LM2576HVT-12
LM2576HVT-15 LM2576HVT-ADJ
TIGER ELECTRONICS CO.,LTD
2
LM2576 Series
Absolute Maximum Ratings
(Note 1)
Parameter
Maximum Supply Voltage
LM2576
LM2576HV
ON/OFF Pin Input Voltage
Output Voltage to Ground (Steady State)
Power Dissipation
Storage Temperature Range
Maximum Junction Temperature
Minimum ESD Rating (C= 100pF, R = 1.5 kΩ)
Lead Temperature (Soldering, 10 Seconds)
Maximum
45
63
-0.3V
≤
V
≤
+V
IN
-1
Internally Limited
-65 to +150
150
2
260
Units
V
V
W
°C
°C
kV
°C
Operating Ratings
Parameter
Temperature Range
LM2576/LM2576HV
Supply Voltage
Value
-40
≤
T
J
≤
+125
40
60
Units
°C
V
LM2576
LM2576HV
Electrical Characteristics LM2576 -3.3,LM2576HV-3.3
Specifications with standard type face are for T
J
= 25°C, and those with
boldface type
apply over full Operating Temperature Range.
Symbol
Parameter
Conditions
Typ
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Output Voltage
V
IN
=12V, I
LOAD
=0.5A
Circuit of
Figure 2
6V
≤
V
IN
≤
40V, 0.5A
≤
I
LOAD
≤
3A Circuit of
Figure 2
6V
≤
V
IN
≤
60V, 0.5A
≤
I
LOAD
≤
3A Circuit of
Figure 2
V
IN
=12V, I
LOAD
=3A
3.3
3.234
3.366
3.168/3.135
3.432/3.465
3.168/3.135
3.450/3.482
V
V(Min)
V(Max)
V
V(Min)
V(Max)
V
V(Min)
V(Max)
%
LM2576-3.3
LM2576HV-3.3
Limit
(Note 2)
Units
(Limits)
V
OUT
Output Voltage
LM2576
Output Voltage
LM2576HV
Efficiency
3.3
V
OUT
3.3
η
75
Electrical Characteristics LM2576 -5.0, LM2576HV-5.0
Specifications with standard type face are for T
J
= 25°C, and those with
boldface type
apply over full Operating Temperature Range.
Symbol
Parameter
Conditions
Typ
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Output Voltage
V
IN
=12V, I
LOAD
=0.5A
Circuit of
Figure 2
0.5A
≤
I
LOAD
≤
3A,
8V
≤
V
IN
≤
40V
Circuit of
Figure 2
0.5A
≤
I
LOAD
≤
3A,
8V
≤
V
IN
≤
60V
Circuit of
Figure 2
V
IN
=12V, I
LOAD
=3A
5.0
4.900
5.100
4.800/4.750
5.200/5.250
4.800/4.750
5.225/5.275
V
V(Min)
V(Max)
V
V(Min)
V(Max)
V
V(Min)
V(Max)
%
LM2576-5.0
LM2576HV-5.0
Limit
(Note 2)
Units
(Limits)
V
OUT
Output Voltage
LM2576
Output Voltage
LM2576HV
Efficiency
5.0
V
OUT
5.0
η
77
3
TIGER ELECTRONICS CO.,LTD
LM2576 Series
Electrical Characteristics LM2576 -12, LM2576HV-12
Specifications with standard type face are for T
J
= 25°C, and those with
boldface type
apply over full Operating Temperature Range.
Symbol
Parameter
Conditions
LM2576-12
LM2576HV-12
Typ
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Output Voltage
V
IN
=25V, I
LOAD
=0.5A
Circuit of
Figure 2
0.5A
≤
I
LOAD
≤
3A,
15V
≤
V
IN
≤
40V
Circuit of
Figure 2
0.5A
≤
I
LOAD
≤
3A,
15V
≤
V
IN
≤
60V
Circuit of
Figure 2
V
IN
=15V, I
LOAD
=3A
12
11.76
12.24
11.52/11.40
12.48/12.60
11.52/11.40
12.54/12.66
V
V(Min)
V(Max)
V
V(Min)
V(Max)
V
V(Min)
V(Max)
%
Limit(Note
2)
Units
(Limits)
V
OUT
Output Voltage
LM2576
Output Voltage
LM2576HV
Efficiency
12
V
OUT
12
η
88
Electrical Characteristics LM2576 -15, LM2576HV-15
Specifications with standard type face are for T
J
= 25°C, and those with
boldface type
apply over full Operating Temperature Range.
Symbol
Parameter
Conditions
LM2576-15
LM2576HV-15
Typ
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Output Voltage
V
IN
=25, I
LOAD
=0.5A
Circuit of
Figure 2
0.5A
≤
I
LOAD
≤
3A,
18≤ V
IN
≤
40V
Circuit of
Figure 2
0.5A
≤
I
LOAD
≤
3A,
18
≤
V
IN
≤
60V
Circuit of
Figure 2
V
IN
=18V, I
LOAD
=3A
15
14.70
15.30
14.40/14.25
15.60/15.75
14.40/14.25
15.68/15.83
V
V(Min)
V(Max)
V
V(Min)
V(Max)
V
V(Min)
V(Max)
%
Limit
(Note 2)
Units
(Limits)
V
OUT
Output Voltage
LM2576
Output Voltage
LM2576HV
Efficiency
15
V
OUT
15
η
88
Electrical Characteristics LM2576-ADJ, LM2576HV-ADJ
Specifications with standard type face are for T
J
= 25°C, and those with
boldface type
apply over full Operating Temperature Range.
Symbol
Parameter
Conditions
LM2576-ADJ
LM2576HV-ADJ
Typ
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Feedback Voltage
V
IN
=12V, I
LOAD
=0.5A,
V
OUT
=5V
Circuit of
Figure 2
0.5A
≤
I
LOAD
≤
3A , 8V
≤
V
IN
≤
40V V
OUT
=5V
Circuit of
Figure 2
0.5A
≤
I
LOAD
≤
3A, 8V
≤
V
IN
≤
60V, V
OUT
=5V
Circuit of
Figure 2
V
IN
=12V, I
LOAD
=3A, V
OUT
=5V
1.230
1.217
1.243
1.193/1.180
1.267/1.280
1.193/1.180
1.273/1.286
V
V(Min)
V(Max)
V
V(Min)
V(Max)
V
V(Min)
V(Max)
%
Limit(Note
2)
Units
(Limits)
V
OUT
Feedback Voltage
LM2576
Feedback Voltage
LM2576HV
Efficiency
1.230
V
OUT
1.230
η
77
TIGER ELECTRONICS CO.,LTD
4
LM2576 Series
All Output Voltage Versions
Electrical Characteristics
Specifications with standard type face are for T
J
= 25°C, and those with
boldface type
apply over full Operating Temperature Range.
Unless otherwise specified, V
IN
=12V for the 3.3V, 5V, and Adjustable version, V
IN
=25V for the 12V version, and V
IN
=30V for the 15V
version, , I
LOAD
=500mA.
Symbol
Parameter
Conditions
LM2576-XX
LM2576HV-XX
Typ
DEVICE PARAMETERS
I
b
f
O
Feedback Bias Current
Oscillator Frequency
V
OUT
=5V (Adjustable Version Only)
(Note 8)
50
52
100/500
47/42
58/63
1.8/2.0
93
4.2/3.5
6.9/7.5
2
30
10
200
nA
kHz
kHz(Min)
kHz(Max)
V
V(Max)
%
%(Min)
A
A(Min)
A(Max)
mA(Max)
mA
mA(Max)
mA
mA(Max)
µA
µA(Max)
Limit
(Note 2)
Units
(Limits)
V
SAT
DC
I
CL
Saturation Voltage
Max Duty Cycle (ON)
Current Limit
I
OUT
=3A (Note 4)
(Note 5)
(Notes 4, 8)
1.4
98
5.8
I
L
Output Leakage Current
Output = 0V
I
Q
I
STBY
Quiescent Current
Standby Quiescent Current
(Notes 6, 7):
Output = -1V
Output = -1V
7.5
5
50
(Note 6)
___
ON/OFF Pin = 5V (OFF)
___
ON/OFF CONTROL
V
IH
__
ON/OFF Pin
V
IL
Logic Input Level
I
IH
__
ON/OFF Pin Input
Current
I
IL
V
OUT
= 0V
V
OUT
= Nominal Output Voltage
__
ON/OFF Pin = 5V (OFF)
__
ON/OFF Pin = 0V (ON)
1.4
1.2
12
0
2.2/2.4
1.0/0.8
30
10
V(Min)
V(Max)
µA
µA(Max)
µA
µA(Max)
Note
Note
Note
Note
Note
Note
Note
Note
1:
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating
Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits.
For guaranteed specifications and test conditions, see the Electrical Characteristics.
2:
All limits guaranteed at room temperature (standa rd type face) and at temperature extremes (bold
type face).
3:
External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system
performance. When the
LM2576/LM2576HV
is used as shown in the
Figure 2
test circuit, system performance will be a
shown in system parameters section of Electrical Characteristics.
4:
Output pin sourcing current. No diode, inductor or capacitor connected to output.
5:
Feedback pin removed from output and connected to 0V.
6:
Feedback pin removed from output and connected to +12V for the Adjustable, 3.3V, and 5V, versions, and +25V for the 12V
and 15V versions, to force the output transistor OFF.
7:
V
IN
=40V (60V for high voltage version).
8:
The oscillator frequency reduces to approximately 11 kHz in the event of an output short or an overload which causes the
regulated output voltage to drop approximately 40% from the nominal output voltage. This self protections feature lowers the
average power dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%.
TIGER ELECTRONICS CO.,LTD
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