LM25117 (ACTIVE)

4.5-42V Wide Vin, Current Mode Synchronous Buck Controller with Tracking

 

Description

The LM25117 is a synchronous buck controller intended for step-down regulator applications from a high voltage or widely varying input supply. The control method is based upon current mode control utilizing an emulated current ramp. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting and ease of loop compensation. The use of an emulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable control of very small duty cycles necessary in high input voltage applications.

The operating frequency is programmable from 50 kHz to 750 kHz. The LM25117 drives external high-side and low-side NMOS power switches with adaptive dead-time control. A user-selectable diode emulation mode enables discontinuous mode operation for improved efficiency at light load conditions. A high voltage bias regulator that allows external bias supply further improves efficiency. The LM25117’s unique analog telemetry feature provides average output current information. Additional features include thermal shutdown, frequency synchronization, hiccup mode current limit and adjustable line undervoltage lockout.

Features

  • LM25117-Q1 is Qualified for Automotive Applications
  • AEC-Q100 Qualified With the Following Results:
    • Device Temperature Grade 1: -40°C to 125°C
      Ambient Operating Temperature Range
  • Emulated Peak Current Mode Control
  • Wide Operating Range from 4.5 V to 42 V
  • Robust 3.3 A Peak Gate Drives
  • Adaptive Dead-time Output Driver Control
  • Free-run or Synchronizable Clock up to 750 kHz
  • Optional Diode Emulation Mode
  • Programmable Output from 0.8 V
  • Precision 1.5% Voltage Reference
  • Analog Current Monitor
  • Programmable Current Limit
  • Hiccup Mode Over Current Protection
  • Programmable Soft-start and Tracking
  • Programmable Line Undervoltage Lockout
  • Programmable Switch-over to External Bias Supply
  • Thermal Shutdown

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Parametrics Compare all products in Buck Controller (External Switch)

 
Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Regulated Outputs (#)
Number of Phases
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Features
Duty Cycle (Max) (%)
Operating Temperature Range (C)
Rating
Package Group
Control Mode
LM25117 LM25116 LM25117-Q1 LM25119 LM25141 LM25145 LM3150 LM5119 TPS40200
4.5    6    4.5    4.5    3.8    6    6    5.5    4.5   
42    42    42    42    42    42    42    65    52   
0.8    1.215    0.8    0.8    1.5    0.8    0.6    0.8    0.7   
41    36    41    41.3    15    40    40    64    46   
20    20    20    40    20    30    12    15    3   
1    1    1    2    1    1    1    2    1   
1    1    1    2    1    1    1    2    1   
50    50    50    50    350    100    200    50    35   
750    1000    750    750    2600    1000    1000    750    500   
4.8    4.6    4.8    6    0.035    1.8    3.5    6    1.5   
Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Synchronous Rectification
Tracking
UVLO Adjustable   
Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Synchronous Rectification   
Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Synchronous Rectification
Tracking
UVLO Adjustable   
Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Synchronous Rectification
UVLO Adjustable   
Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Spread Spectrum
Synchronous Rectification
UVLO Fixed   
Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Synchronous Rectification
Tracking
UVLO Adjustable   
Adjustable Current Limit
Enable
Frequency Synchronization
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Synchronous Rectification
UVLO Adjustable   
Frequency Synchronization   
98    98    98    98    99    99    96    98    90   
-40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 85   
Catalog    Catalog    Automotive    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog   
HTSSOP
WQFN   
HTSSOP    HTSSOP
WQFN   
WQFN    VQFN    VQFN    HTSSOP    WQFN    SOIC
SON   
Current Mode    Current Mode    Current Mode    Current Mode    Current Mode    Voltage Mode    COT with emulated ripple    Current Mode    Voltage Mode   

Other qualified versions of LM25117

Version Part Number Definition
Automotive LM25117-Q1 Q100 devices qualified for high-reliability automotive applications targeting zero defects
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WEBENCH® Designer LM25117

  Min   Max Range
Vin  V 4.5 to 42.0V
Vout  V 0.8 to 41.0V
Iout  A ≤ 17A
Ambient Temp  °C -40 to 125°C


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