LM25118 (ACTIVE)

3-42V Wide Vin, Current Mode Non-Synchronous Buck-Boost Controller

 

Description

The LM25118 wide voltage range Buck-Boost switching regulator controller features all of the functions necessary to implement a high-performance, cost-efficient Buck-Boost regulator using a minimum of external components. The Buck-Boost topology maintains output voltage regulation when the input voltage is either less than or greater than the output voltage making it especially suitable for automotive applications. The LM25118 operates as a buck regulator while the input voltage is sufficiently greater than the regulated output voltage and gradually transitions to the buck-boost mode as the input voltage approaches the output. This dual-mode approach maintains regulation over a wide range of input voltages with optimal conversion efficiency in the buck mode and a glitch-free output during mode transitions. This easy-to-use controller includes drivers for the high-side buck MOSFET and the low-side boost MOSFET. The control method of the regulator is based upon current mode control using an emulated current ramp. Emulated current mode control reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable control of the very small duty cycles necessary in high input voltage applications. Additional protection features include current limit, thermal shutdown, and an enable input. The device is available in a power-enhanced, 20-pin HTSSOP package featuring an exposed die attach pad to aid thermal dissipation.

Features

  • Input Voltage Operating Range From 3 V to 42 V
  • Emulated Peak Current Mode Control
  • Smooth Transition Between Step-Down and Step-Up Modes
  • Switching Frequency Programmable to 500 KHz
  • Oscillator Synchronization Capability
  • Internal High Voltage Bias Regulator
  • Integrated High and Low-Side Gate Drivers
  • Programmable Soft-Start Time
  • Ultra-Low Shutdown Current
  • Enable Input
  • Wide Bandwidth Error Amplifier
  • 1.5% Feedback Reference Accuracy
  • Thermal Shutdown
  • Package: 20-Pin HTSSOP (Exposed Pad)
  • Create a Custom Design Using the LM25118 With the WEBENCH® Power Designer

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Parametrics Compare all products in Buck/Boost or Inverting Controller (External Switch)

 
Topology
Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Switch Current Limit (Min) (A)
Duty Cycle (Max) (%)
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Features
Iout (Max) (A)
Operating Temperature Range (C)
Rating
Package Group
LM25118 LM25118-Q1 LM5118 LM5118-Q1 LM5175 LM5175-Q1 LM5176
Buck/Boost    Buck/Boost    Buck/Boost    Buck/Boost    Buck/Boost    Buck/Boost    Buck/Boost   
3    3    3    3    3.5    3.5    4   
42    42    75    75    42    42    55   
1.23    1.23    1.23    1.23    0.8    0.8    0.8   
38    38    70    70    55    55    55   
4    4    4    4    20    20    20   
98    98    98    98    100    100    100   
50    50    50    50    100    100    100   
500    500    500    500    600    600    600   
4.5    4.5    4.5    4.5    1.65    1.65    1.65   
Enable
Frequency Synchronization   
Enable
Frequency Synchronization   
Enable
Frequency Synchronization   
Enable
Frequency Synchronization   
Adjustable Current Limit
Enable
Frequency Synchronization
Power Good
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
Adjustable Current Limit
Enable
Frequency Synchronization
Power Good
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
Adjustable Current Limit
Enable
Frequency Synchronization
Power Good
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
10    10    10    10    20    20     
-40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125   
Catalog    Automotive    Catalog    Automotive    Catalog    Automotive    Catalog   
HTSSOP    HTSSOP    HTSSOP    HTSSOP    HTSSOP
VQFN   
HTSSOP    HTSSOP   

Other qualified versions of LM25118

Version Part Number Definition
Automotive LM25118-Q1 Q100 devices qualified for high-reliability automotive applications targeting zero defects
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WEBENCH® Designer LM25118

  Min   Max Range
Vin  V 3.0 to 42.0V
Vout  V 1.23 to 38V
Iout  A ≤ 10A
Ambient Temp  °C -40 to 125°C


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