LM2574-5.0BN

LM2574-5.0BN Datasheet

LM2574

Part	Datasheet
LM2574-5.0BN	LM2574-5.0BN (pdf)

Related Parts	Information
LM2574-12BN	LM2574-12BN
LM2574-3.3BN	LM2574-3.3BN

PDF Datasheet Preview
LM2574 Micrel LM2574 52kHz Simple 0.5A Buck Regulator Final Information The LM2574 family is a series of easy to use fixed and adjustable 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, 5V, and 12V fixed output versions, 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-bycycle 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. Pin Configuration FB 1 SIG GND 2 ON/OFF 3 PWR GND 4 8* 7 OUTPUT 6* 5 VIN 8-pin DIP N 1 2 FB 3 SIG GND 4 ON/OFF 5 PWR GND 6 7 14 13 * 12 OUTPUT 11 * 10 VIN 9* 8* 14-pin SOIC WM * NC solder to printed circuit for maximum heat transfer • 3.3V, 5V, 12V, and Adjustable Output Versions • Adjustable Version Output 1.23V to 37V ±4% Max. over Line and Load Conditions. • 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 • Simple High-efficiency Step-down Buck Regulator • Efficient Pre-Regulator for Linear Regulators • On-card Switching Regulators • Positive to Negative Converter Buck-Boost Ordering Information Part Number LM2574BN LM2574BWM LM2574-3.3BN LM2574-3.3BWM LM2574-5.0BN LM2574-5.0BWM LM2574-12BN LM2574-12BWM Temp. Range to +85°C to +85°C to +85°C to +85°C to +85°C to +85°C to +85°C to +85°C Package 8-pin Plastic DIP 14-pin Wide SOIC 8-pin Plastic DIP 14-pin Wide SOIC 8-pin Plastic DIP 14-pin Wide SOIC 8-pin Plastic DIP 14-pin Wide SOIC 40V MAX UNREGULATED DC IN CIN 22µF FB VIN LM2574 OUT PWR SIG ON/ GND OFF 330µH REGULATED OUTPUT 0.5A 11DQ05 COUT 220µF Figure Fixed Output Regulator Circuit Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 408 944-0800 • fax + 1 408 944-0970 • August 1999 LM2574 LM2574 Absolute Maximum Ratings Maximum Supply Voltage LM2574 45V OFF Pin Input Voltage V VIN Output Voltage to Ground Steady State Power Dissipation Internally Limited Storage Temperature Range to +150°C Minimum ESD Rating C = 100pF, R = 2kV FB Pin 1kV Lead Temperature soldering, 10 sec. 260°C Maximum Junction Temperature 150°C Micrel Operating Ratings Temperature Range LM2574 40°C TJ +125°C Supply Voltage LM2574 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 = 100mA. Symbol Parameter Condition Min Typ Max Units SYSTEM PARAMETERS, ADJUSTABLE REGULATORS Note 3 Test Circuit Figure 2 VOUT Feedback Voltage Feedback Voltage LM2574 VIN = 12V, ILOAD = 0.1A, VOUT = 5V 0.1A ILOAD 0.5A, VIN 40V, VOUT = 5V Efficiency VIN = 12V, ILOAD = 0.1A, VOUT = 5V SYSTEM PARAMETERS, 3.3V REGULATORS Note 3 Test Circuit Figure 3

PDF Datasheet Preview

LM2574

Micrel

LM2574
52kHz Simple 0.5A Buck Regulator Final Information

The LM2574 family is a series of easy to use fixed and adjustable 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, 5V, and 12V fixed output versions, 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-bycycle 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.

Pin Configuration

FB 1 SIG GND 2

ON/OFF 3 PWR GND 4
8* 7 OUTPUT 6* 5 VIN
8-pin DIP N
*1 *2 FB 3 SIG GND 4 ON/OFF 5 PWR GND 6 *7
14 * 13 * 12 OUTPUT 11 * 10 VIN 9* 8*
14-pin SOIC WM
* NC solder to printed circuit for maximum heat transfer
• 3.3V, 5V, 12V, and Adjustable Output Versions
• Adjustable Version Output 1.23V to 37V ±4% Max. over

Line and Load Conditions.
• 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
• Simple High-efficiency Step-down Buck Regulator
• Efficient Pre-Regulator for Linear Regulators
• On-card Switching Regulators
• Positive to Negative Converter Buck-Boost
Ordering Information

Part Number LM2574BN LM2574BWM LM2574-3.3BN LM2574-3.3BWM LM2574-5.0BN LM2574-5.0BWM LM2574-12BN LM2574-12BWM

Temp. Range to +85°C to +85°C to +85°C to +85°C to +85°C to +85°C to +85°C to +85°C

Package 8-pin Plastic DIP 14-pin Wide SOIC 8-pin Plastic DIP 14-pin Wide SOIC 8-pin Plastic DIP 14-pin Wide SOIC 8-pin Plastic DIP 14-pin Wide SOIC
40V MAX UNREGULATED

DC IN

CIN 22µF

FB VIN

LM2574 OUT

PWR SIG ON/ GND OFF
330µH

REGULATED OUTPUT 0.5A
11DQ05

COUT 220µF

Figure Fixed Output Regulator Circuit

Micrel, Inc.
• 1849 Fortune Drive
• San Jose, CA 95131
• USA
• tel + 1 408 944-0800
• fax + 1 408 944-0970
•

August 1999

LM2574

LM2574

Absolute Maximum Ratings

Maximum Supply Voltage LM2574 45V

OFF Pin Input Voltage V VIN Output Voltage to Ground Steady State Power Dissipation Internally Limited Storage Temperature Range to +150°C Minimum ESD Rating

C = 100pF, R = 2kV FB Pin 1kV Lead Temperature soldering, 10 sec. 260°C Maximum Junction Temperature 150°C

Micrel

Operating Ratings

Temperature Range LM2574 40°C TJ +125°C

Supply Voltage LM2574 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 = 100mA.

Symbol Parameter

Condition

Min Typ Max Units

SYSTEM PARAMETERS, ADJUSTABLE REGULATORS Note 3 Test Circuit Figure 2

VOUT

Feedback Voltage

Feedback Voltage LM2574

VIN = 12V, ILOAD = 0.1A, VOUT = 5V
0.1A ILOAD 0.5A, VIN 40V, VOUT = 5V

Efficiency

VIN = 12V, ILOAD = 0.1A, VOUT = 5V

SYSTEM PARAMETERS, 3.3V REGULATORS Note 3 Test Circuit Figure 3

Notice: we do not provide any warranties that information, datasheets, application notes, circuit diagrams, or software stored on this website are up-to-date or error free. The archived LM2574-5.0BN Datasheet file may be downloaded here without warranties.

Datasheet ID: LM2574-5.0BN 647887