Voltage Regulator. LM2576 Datasheet

LM2576 Regulator. Datasheet pdf. Equivalent

LM2576 Datasheet
Recommendation LM2576 Datasheet
Part LM2576
Description 52kHz Simple 3A Buck Voltage Regulator
Feature LM2576; LM2576 Micrel LM2576 52kHz Simple 3A Buck Voltage Regulator General Description The LM2576 series.
Manufacture Micrel Semiconductor
Datasheet
Download LM2576 Datasheet




Micrel Semiconductor LM2576
LM2576
LM2576
Micrel, Inc.
52kHz Simple 3A Buck Regulator
General Description
The LM2576 series of monolithic integrated circuits provide
all the active functions for a step-down (buck) switching
regulator. Fixed versions are available with a 3.3V, 5V, or 12V
fixed output. Adjustable versions have an output voltage
range from 1.23V to 37V. Both versions are capable of driving
a 3A load with excellent line and load regulation.
These regulators are simple to use because they require a
minimum number of external components and include internal
frequency compensation and a fixed-frequency oscillator.
The LM2576 series offers a high efficiency replacement for
popular three-terminal adjustable linear regulators. It
substantially reduces the size of the heat sink, and in many
cases no heat sink is required.
A standard series of inductors available from several different
manufacturers are ideal for use with the LM2576 series. This
feature greatly simplifies the design of switch-mode power
supplies.
The feedback voltage is guaranteed to ±2% tolerance for
adjustable versions, and the output voltage is guaranteed to
±3% for fixed versions, within specified input voltages and
output load conditions. The oscillator frequency is guaranteed
to ±10%. External shutdown is included, featuring less than
200µA standby current. The output switch includes cycle-by-
cycle current limiting and thermal shutdown for full protection
under fault conditions.
Features
• 3.3V, 5V, 12V, and adjustable output versions
• Voltage over specified line and load conditions:
Fixed version: ±3% max. output voltage
Adjustable version: ±2% max. feedback voltage
• Guaranteed 3A output current
• Wide input voltage range:
4V to 40V
• Wide output voltage range
1.23V to 37V
• Requires only 4 external components
• 52kHz fixed frequency internal oscillator
• Low power standby mode IQ typically < 200µA
• 80% efficiency (adjustable version typically > 80%)
• Uses readily available standard inductors
• Thermal shutdown and current limit protection
• 100% electrical thermal limit burn-in
Applications
• Simple high-efficiency step-down (buck) regulator
• Efficient pre-regulator for linear regulators
• On-card switching regulators
• Positive to negative converter (inverting Buck-Boost)
• Isolated Flyback Converter using minimum number of
external components
• Negative Boost Converter
Typical Applications
7V40V
Unregulated
DC Input 1
4 Feedback
+VIN LM2575-5.0 Output L1
+5V, 1A
Regulated
Output
+
CIN
100µF
3 52
Gnd On/Off
330µH
D1
1N5822
+
COUT
330µF
Note: Pin numbers are for TO-220 Package
Fixed Regulator in Typical Application
7V40V
Unregulated
DC Input
1
+VIN
LM2575
+
CIN
100µF
35
Gnd On/Off
4 Feedback
Output L1
2 330µH
D1
1N5822
+
COUT
330µF
+5V, 1A
Regulated
Output
R2 3.09k
R1 1k
Note: Pin numbers are for TO-220 Package
( )VOUT = 1.23
1
+
R2
R1
Adjustable Regulator in Fixed Output Application
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
August 2005
1 M9999-082605-B



Micrel Semiconductor LM2576
LM2576
Micrel, Inc.
Ordering Information
Part Number
Standard
RoHS Compliant**
LM2576BT*
LM2576WT*
LM2576-3.3BTLM2576-3.3WT
LM2576-5.0BTLM2576-5.0WT
LM2576-12BTLM2576-12WT
LM2576BU*
LM2576WU*
LM2576-3.3BU LM2576-3.3WU
LM2576-5.0BU LM2576-5.0WU
LM2576-12BU LM2576-12WU
Range
40°C to +85°C
40°C to +85°C
40°C to +85°C
40°C to +85°C
40°C to +85°C
40°C to +85°C
40°C to +85°C
40°C to +85°C
* Adjustable output regulators.
**RoHS compliant with "hot-melting solder" exemption.
Contact factory for bent or staggered leads option.
Temperature
Package
TO-220-5
TO-220-5
TO-220-5
TO-220-5
TO-263-5
TO-263-5
TO-263-5
TO-263-5
Pin Configurations
5-LEAD TO-220 (T)
GND
5- ON/OFF
4- FEEDBACK
3- GROUND
2- OUTPUT
1- VIN
5-LEAD TO-263 (U)
GND
5- ON/OFF
4- FEEDBACK
3- GROUND
2- OUTPUT
1- VIN
M9999-082605-B
2
August 2005



Micrel Semiconductor LM2576
LM2576
Absolute Maximum Ratings (Note 1)
Maximum Supply Voltage
ON/OFF Pin Input Voltage
Output Voltage to Ground (Steady State)
Power Dissipation
Storage Temperature Range
Minimum ESD Rating
C = 100pF, R = 1.5k
FB Pin
Lead Temperature (soldering, 10 sec.)
Maximum Junction Temperature
45V
0.3V V +40V
1V
Internally Limited
65°C to +150°C
2 kV
1 kV
260°C
150°C
Operating Ratings
Temperature Range
Supply Voltage
Micrel, Inc.
40°C TJ +125°C
40V
Electrical Characteristics Specifications with standard typeface are for TJ = 25°C, and those with boldface type apply
over full Operating Temperature Range. Unless otherwise specified, VIN = 12V, and ILOAD = 500mA.
LM2576
Symbol Parameter
Conditions
Typ Limit
(Note 2)
Units
(Limits)
SYSTEM PARAMETERS, ADJUSTABLE REGULATORS (Note 3) Test Circuit Figure 1
VOUT
Feedback Voltage
VIN = 12V , ILOAD = 0.5A
VOUT = 5V
1.230
1.217
1.243
V
V(min)
V(max)
VOUT
Feedback Voltage
LM2576
0.5A ILOAD 3A, 8V VIN 40V
VOUT = 5V
1.230
1.193/1.180
1.267/1.280
V
V(min)
V(max)
η Efficiency
VIN = 12V, ILOAD = 3A, VOUT = 5V
SYSTEM PARAMETERS, 3.3V REGULATORS (Note 3) Test Circuit Figure 1
82
%
VOUT
Output Voltage
VIN = 12V , ILOAD = 0.5A
VOUT = 3.3V
3.3
3.234
3.366
V
V(min)
V(max)
VOUT
Output Voltage
LM2576-3.3
0.5A ILOAD 3A, 6V VIN 40V
VOUT = 3.3V
3.3
3.168/3.135
3.432/3.465
V
V(min)
V(max)
η Efficiency
VIN = 12V, ILOAD = 3A
SYSTEM PARAMETERS, 5V REGULATORS (Note 3) Test Circuit Figure 1
75
%
VOUT
Output Voltage
VIN = 12V , ILOAD = 0.5A
VOUT = 5V
5.0
4.900
5.100
V
V(min)
V(max)
VOUT
Output Voltage
LM2576-5.0
0.5A ILOAD 3A, 8V VIN 40V
VOUT = 5V
5.0
4.800/4.750
5.200/5.250
V
V(min)
V(max)
η Efficiency
VIN = 12V, ILOAD = 3A
SYSTEM PARAMETERS, 12V REGULATORS (Note 3) Test Circuit Figure 1
82
%
VOUT
Output Voltage
VIN = 25V , ILOAD = 0.5A
VOUT = 12V
12
11.760
12.240
V
V(min)
V(max)
VOUT
Output Voltage
LMLM2576-12
0.5A ILOAD 3A, 15V VIN 40V
VOUT = 12V
12
11.520/11.400
12.480/12.600
V
V(min)
V(max)
η Efficiency
VIN = 25V, ILOAD = 3A
88
%
August 2005
3 M9999-082605-B







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