LM2574-12BN Micrel Inc, LM2574-12BN Datasheet

IC REGULATOR BUCK 0.5A 8-DIP

LM2574-12BN

Manufacturer Part Number
LM2574-12BN
Description
IC REGULATOR BUCK 0.5A 8-DIP
Manufacturer
Micrel Inc
Type
Step-Down (Buck)r
Datasheet

Specifications of LM2574-12BN

Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
12V
Current - Output
500mA
Frequency - Switching
52kHz
Voltage - Input
4.75 ~ 40 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Through Hole
Package / Case
8-DIP (0.300", 7.62mm)
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Power - Output
-

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LM2574-12BN
Manufacturer:
TI
Quantity:
2 000
General Description
The LM2574 family is a series of easy to use fixed and ad-
justable switching voltage regulators. The LM2574 contains
all of the active circuitry necessary to construct a stepdown
(buck) switching regulator and requires a minimum of external
components.
The LM2574 is available in 3.3V and 5V fixed output ver-
sions, or an adjustable version with an output voltage range
of 1.23V to 37V. Output voltage is guaranteed to ±4% for
specified input and load conditions.
The LM2574 can supply 0.5A while maintaining excellent
line and load regulation. The output switch includes cycle-
by-cycle current limiting, as well as thermal shutdown for full
protection under fault conditions.
An external shutdown connection selects operating or standby
modes. Standby current is less than 200µA.
Heat sinks are generally unnecessary due the regulator’s
high efficiency. Adequate heat transfer is usually provided
by soldering all package pins to a printed circuit board.
The LM2574 includes internal frequency compensation and
an internal 52kHz fixed frequency oscillator guaranteed to
±10% of the frequency.
Circuits constructed around the LM2574 use a standard
series of inductors which are available from several different
manufacturers.
All support documentation can be found on Micrel’s web site
at www.micrel.com.
Typical Application
July 2005
LM2574
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
U N R E G U L A T E D
40V MAX
DC IN
22µF
C
Figure 1. Fixed Output Regulator Circuit
IN
V
PWR
GND
IN
LM2574
GND
SIG
OUT
OFF
ON/
1
FB
Features
• 3.3V, 5V, 12V, and adjustable output versions
• Adjustable version output 1.23V to 37V ±4% max. over
• Guaranteed 0.5A output current
• Wide input voltage, up to 40V
• Thermal shutdown and current limit protection
• Requires only 4 external components.
• Shutdown capability (standby mode)
• Low power standby mode < 200µA Typical
• High-efficiency
• 52kHz fixed frequency internal oscillator
• Uses standard inductors
Applications
• Simple high-efficiency step-down (buck) regulator
• Efficient pre-regulator for linear regulators
• On-card switching regulators
• Positive to negative converter (buck-boost)
line and load conditions.
11DQ05
330µH
52kHz Simple 0.5A Buck Regulator
REGULATED
O U T P U T
0.5A
C
220µF
OU T
LM2574
M9999-072805
Micrel, Inc.

Related parts for LM2574-12BN

LM2574-12BN Summary of contents

Page 1

... LM2574 General Description The LM2574 family is a series of easy to use fixed and ad- justable switching voltage regulators. The LM2574 contains all of the active circuitry necessary to construct a stepdown (buck) switching regulator and requires a minimum of external components. The LM2574 is available in 3.3V and 5V fixed output ver- sions adjustable version with an output voltage range of 1.23V to 37V. Output voltage is guaranteed to ± ...

Page 2

... LM2574 Ordering Information Part Number Standard Pb-Free LM2574BN LM2574YN LM2574-3.3BN LM2574-3.3YN LM2574-5.0BN LM2574-5.0YN Pin Configuration PWR GND 4 M9999-072805 Junction Temp. Range Package –40ºC to +85ºC 8-pin Plastic DIP –40ºC to +85ºC 8-pin Plastic DIP –40ºC to +85ºC ...

Page 3

... All limits at temperature extremes are guaranteed via testing. 3. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM2574 is used as shown in Figure 1 test circuit, system performance will be shown in system parameters section of “Electrical Charac- teristics.” ...

Page 4

... OUT OUT ON/OFF = 5V (OFF) ON/OFF = 0V (ON LM2574 330µH (adjustable) OUT PWR SI G ON/ GND GND OFF 11DQ06 Figure 2. Adjustable Regulator Test Circuit LM2574– C 330µ 22µF OUT ON/ GND GND 11DQ06 Figure 3. Fixed Regulator Test Circuit 4 Min Typ 0 0.7 1 ...

Page 5

... LM2574 Typical Characteristics (Circuit of Figure 1) Supply Current 20 Measured at Ground Pin 25˚ OUT = 0. INPUT VOLTAGE ( V) Current Limit 1 25V 1 0.5 0 -75 -50 - 100125 150 TEM PER ATU ˚ Minimum Operating Voltage 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 V OUT = 1.23V 1 100 mA 0.5 0 -75 -50 - 100125150 TEM PER ATU ˚ ...

Page 6

... LM2574 Typical Performance Characteristics (continued) Feedback Voltage -10 -15 -20 -25 -75 -50 - TEM PER ATU ˚ Adjustable version only M9999-072805 Normalized Feedback Voltage vs Duty Cycle 12V 100mA Normalized toT J = 25˚ -10 -15 - 100125150 100 40V 100 Micrel, Inc. July 2005 ...

Page 7

... LM2574 Block Diagrams INTERNAL REGULATOR F EED - 4 BACK FIXED GAIN 3.1k + COM PARAT OR 1. 1.23V BAND-GAP 52 kHz RESET REFERENCE OSCILLATOR SHUTDOWN Note: Pin numbers are for the TO-220 package Fixed Regulator July 2005 ON/OFF ON/OFF 1 F EED - 1/2 AMP 4 BACK SW ITCH DRIVER ...

Page 8

... LM2574 Package Information 0.018 (0.57) MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA + 1 (408) 944-0800 TEL This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. ...

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