4.5V to 42V, 3A Step-Down DC/DC Switching Regulator - LM25576

LM25576 (ACTIVE)

4.5V to 42V, 3A Step-Down DC/DC Switching Regulator


Recommended alternative parts

  • LM43603  - The device has SIMILAR FUNCTIONALITY but is not functionally equivalent to the compared device.   Synchronous 36V, 3A Regulator - Higher efficiency, Low Quiescent Current, Smaller Solution Size


The LM25576 is an easy to use SIMPLE SWITCHER® buck regulator which allows design engineers to design and optimize a robust power supply using a minimum set of components. Operating with an input voltage range of 6 - 42V, the LM25576 delivers 3A of continuous output current with an integrated 170mΩ N-Channel MOSFET. The regulator utilizes an Emulated Current Mode architecture which provides inherent line regulation, tight load transient response, and ease of loop compensation without the usual limitation of low-duty cycles associated with current mode regulators. The operating frequency is adjustable from 50kHz to 1MHz to allow optimization of size and efficiency. To reduce EMI, a frequency synchronization pin allows multiple IC’s from the LM(2)557x family to self-synchronize or to synchronize to an external clock. The LM25576 ensures robustness with cycle-by-cycle current limit, short-circuit protection, thermal shut-down, and remote shut-down. The device is available in a power enhanced HTSSOP-20 package featuring an exposed die attach pad for thermal dissipation. The LM25576 is supported by the full suite of WEBENCH On-Line design tools.


  • LM25576-Q1 is an Automotive Grade Product that is AEC-Q100 Grade 1 Qualified (−40°C to + 125°C Operating Junction Temperature)
  • Integrated 42V, 170mΩ N-channel MOSFET
  • Ultra-Wide Input Voltage Range from 6V to 42V
  • Adjustable Output Voltage as Low as 1.225V
  • 1.5% Feedback Reference Accuracy
  • Operating Frequency Adjustable Between 50kHz and 1MHz with Single Resistor
  • Master or Slave Frequency Synchronization
  • Adjustable Soft-Start
  • Emulated Current Mode Control Architecture
  • Wide Bandwidth Error Amplifier
  • Built-in Protection
  • Automotive Grade Product Datasheet that is AEC-Q100 Grade 0 Qualified is Available Upon Request.
    • (−40°C to + 150°C Operating Junction Temperature)


  • HTSSOP-20EP (Exposed Pad)

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Parametrics Compare all products in Buck Converter (Integrated Switch)

Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Regulated Outputs (#)
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Special Features
Control Mode
Duty Cycle (Max) (%)
Operating Temperature Range (C)
Package Group
LM25576 LM25574 LM25575 LM43603
6    6    6    3.5   
42    42    42    36   
1.23    1.23    1.23    1   
40    40    40    28   
3    0.5    1.5    3   
1    1    1    1   
50    50    50    200   
1000    1000    1000    2200   
1    1    1    0.027   
Frequency Synchronization    Frequency Synchronization    Frequency Synchronization    Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Synchronous Rectification
Current Mode    Current Mode    Current Mode    Current Mode   
95    95    95    99   
-40 to 125    -40 to 125    -40 to 125    -40 to 125   
Catalog    Catalog    Catalog    Catalog   

Other qualified versions of LM25576

Version Part Number Definition
Automotive LM25576-Q1 Q100 devices qualified for high-reliability automotive applications targeting zero defects

WEBENCH® Designer LM25576

  Min   Max Range
Vin  V 6.0 to 42.0V
Vout  V 1.225 to 42V
Iout  A 3A
Ambient Temp  °C -40 to 125°C
Product Option