Voltage Regulator. LM2576 Datasheet

LM2576 Regulator. Datasheet pdf. Equivalent

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



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



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





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