Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com
PIN CONNECTIONS
3.0A Step Down Switching voltage Regulator LM2576
Adjustable & Fix Output
Pin Connection
Ordering Information
Devices Package Temp.
LM2576T-X TO-220
-40 °C to 125 °C
LM2576S-X TO-263
-40°C to 125 °C
LM2576J-X LPDD
-40°C to 125 °C
X= Output Voltage (X=3.3V, 5.0V, 12V, 15V or Blank for Adjustable)
Consult factory for other fixed voltages.
Description
The Bay Linear LM2576 contains fixed and adjustable
switching voltage regulators that require a minimum of
external components. All circuitry necessary to build a
buck-switching regulator is included.
The LM2576 is available in 3.3V; 5V, 12V & 15V fixed
voltages, or an adjustable version with an output voltage
range from 1.23V to 37V. The guaranteed accuracy for
specified input and load conditions is ±4%.
The LM2576 can supply 3A with an excellent load and
line regulation. Protection such as cycle-by-cycle
current limiting or thermal shutdown has been designed.
In standby mode, the current consumption has been
minimized (200µA).
For 1A step-down switching regulators refer to B2575
data sheets
Features
• Guaranteed 3A Output Current
• High Efficiency
• Wide Input Voltage, up to 40V
• 3.3V, 5V, 12V, 15V and Adjustable Output
Versions
• Thermal Shutdown and Current Limit
Protection
• Requires only 4 External Components
• Low Power Standby Mode < 200µA Typical
• Shutdown Capability (Standby Mode)
• 52kHz Fixed Frequency Internal Oscillator
• Uses Standard Inductors
• Pin-to-Pin Compatible with LM2576
Applications
• Efficient Pre-Regulator for Linear Regulators
• On-card Switching Regulators
• Positive to Negative Converter (Buck-Boost)
• Simple High-efficiency Step-down (Buck)
•
Portable Instruments
TO-263-5 Package
Top View
45
BAY
B2576
GND
V
OUT
V
IN
1)
3)
4)
5)
FB
ON/OFF
2)
123
TO-220-5 Package
Top View
GND
V
OUT
V
IN
1)
3)
4)
5)
2)
FB
ON/OFF
54321
BAY
B2576
Bay Linear
Inspire the Linear Power
Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com
LM2576
Absolute Maximum Rating
Parameter Symbol Value Unit
Maximum Input Voltage VIN 45 V
Power Dissipation PO Internally Limited W
Off Pin Input Voltage -0.3V<V<VIN
Output Voltage -1 V
Supply Voltage 40 V
Operating Junction
Temperature Range
Control Section
Power Transistor
TJ
-40<TJ<85
Storage Temperature Range TSTG -65 to 150
Lead Temperature (Soldering 10
Sec.) TLEAD 260
°C
ELECTRICAL CHARACTERISTICS TA = 25°C VIN = 12V, ILOAD= 100mA unless otherwise specified.
Boldface type applies over full Operating Temperature Range.
Parameter Conditions LM2576
Typ Min Max
Units
Ad
j
ustable Re
g
ulators
(
Note 3
)(
Note 8
)
VIN = 12V, ILOAD = 0.5A, VOUT = 5V 1.230 1.217 1.243 V
Output Voltage (VOUT) 0.5A ≤ ILOAD ≤ 3A, 6V≤ VIN ≤ 40V, VOUT
=5V
1.230
1.230
1.193
1.180
1.267
1.280 V
Efficiency (Note 7) VIN = 12V, ILOAD = 3A, VOUT = 5V 82 %
3.3V Version (Note 3)(Note 9)
VIN = 12V, ILOAD = 0.5A, VOUT = 3.3V 3.3 3.234 3.366 V
Output Voltage (VOUT) 0.5A ≤ ILOAD
≤
3A, 6V
≤
VIN
≤
40V,
VOUT = 3.3V
3.3
3.3
3.168
3.135
3.432
3.465 V
Efficiency VIN = 12V, ILOAD = 3A 75 %
5V Version (Note 3)(Note 9)
VIN = 12V, ILOAD = 0.5A, VOUT = 5V 5.0 4.900 5.100 V
Output Voltage (VOUT) 0.5A ≤ ILOAD
≤
3A, 8V
≤
VIN
≤
40V,
VOUT = 5V
5.0
5.0
4.800
4.750
5.200
5.250 V
Efficiency (Note 7) VIN = 12V, ILOAD = 3A, VOUT = 5V 82 %
12V Version (Note 3)(Note 9)
VIN = 25V, ILOAD = 0.5A, VOUT = 12V 12 11.760 12.240 V
Output Voltage (VOUT) 0.5A ≤ ILOAD
≤
3A, 15V
≤
VIN
≤
40V,
VOUT = 12V
12
12
11.520
11.400
12.480
12.600 V
Efficiency (Note 7) VIN = 25V, ILOAD = 3A 88 %
15V Version(Note 3)(Note 9)
VIN = 30V, ILOAD = 0.5A, VOUT = 15V 15 14.700 15.300 V
Output Voltage (VOUT) 0.5A ≤ ILOAD ≤ 3A, 18V ≤ VIN ≤ 40V,
VOUT = 15V
15
15
14.400
14.250
15.600
15.750 V
Efficiency (Note 7) VIN = 30V, ILOAD = 3A 88 %
Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com
LM2576
ELECTRICAL CHARACTERISTICS TA = 25°C VIN = 12V, ILOAD= 100mA unless otherwise specified.
Boldface type applies over full Operating Temperature Range.
Parameters Conditions
Typ
LM2576
Min
Max Units
Adjustable Regulator
Feedback Bias Current VOUT = 5V 50 100
500 nA
Fixed and Adjustable Regulators
Oscillator Frequency 52 47
42
58
63 kHz
Saturation Voltage IOUT = 0.5A, (Note 4) 1.4 1.8
2.0 V
Max Duty Cycle (Note 5) 98 93 %
Current Limit Peak Current, tON≤ 3µs, (Note 4) 5.8 4.2
3.5
6.9
7.5 A
Output Leakage Current VIN, (Note 6), Output = 0V
(Note 6 ), Output = -1V
7.5 2
30 mA
Quiescent Current (Note 6) 5 10 mA
Standby Quiescent Current ON/OFF Pin = 5V (OFF) 50 200 µA
Thermal Resistance
T,U package, Junction to Ambient,
(Note 7)
T,U package, Junction to case
65
2
°C/W
ON/OFF Control, Fixed & Adjustable Regulators (Note 8) (Note9)
OFF Input Level VOUT = 0V 1.4 2.2
2.4 V
ON Input Level VOUT = 15V or 5V 1.2 1.0
0.8 V
OFF Logic Current ON/OFF Pin = 5V (OFF) 4 30 µA
ON Logic Current ON/OFF Pin = 0V (ON) 0.01 10 µA
Note 1: Absolute Maxium Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate test conditions for which the device s
intended to be functional, but do not guarantee specific performance limits. For quaranteed specifications and test conditions see the Electrical Characteristics.
Note 2: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100%
production tested. All limits at temperature extremes are guaranteed via testing.
Note 3: External components such as the diode, inductor and capacitor can affect the system performance.
Note 4: Output (pin 2) sourcing current. No diode, inductor, or capacitor connected to input.
Note 5: Feedback (pin 4) removed from output and connected to 0V.
Note 6: Feedback (pin 4) removed from output and connected to 12V to force the output transistor OFF.
Note 7: Junction to ambient thermal resistance with approximately 1 square inches of PC board cooper surrounding the leads.
Note 8: Test circuit refers to figure 2.
Note 9: Test circuit refers to figure 3.
Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com
LM2576
Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com
LM2576
Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com
LM2576
Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com
LM2576
Advance Information- These data sheets contain descriptions of products that are in development. The specifications are based on the engineering calculations,
computer simulations and/ or initial prototype evaluation.
Preliminary Information- These data sheets contain minimum and maximum specifications that are based on the initial device characterizations. These limits are
subject to change upon the completion of the full characterization over the specified temperature and supply voltage ranges.
The application circuit examples are only to explain the representative applications of the devices and are not intended to guarantee any circuit
design or permit any industrial property right to other rights to execute. Bay Linear takes no responsibility for any problems related to any
industrial property right resulting from the use of the contents shown in the data book. Typical parameters can and do vary in different
applications. Customer’s technical experts must validate all operating parameters including “ Typical” for each customer application.
LIFE SUPPORT AND NUCLEAR POLICY
Bay Linear products are not authorized for and should not be used within life support systems which are intended for surgical
implants into the body to support or sustain life, in aircraft, space equipment, submarine, or nuclear facility applications without
the specific written consent of Bay Linear President.
