7.5-100V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator - LM5018


7.5-100V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator



The LM5018 is a 100-V, 300-mA synchronous step-down regulator with integrated high-side and low-side MOSFETs. The constant-on-time (COT) control scheme employed in the LM5018 device requires no loop compensation, provides excellent transient response, and enables very low step-down ratios. The on-time varies inversely with the input voltage resulting in nearly constant frequency over the input voltage range. A high-voltage startup regulator provides bias power for internal operation of the IC and for integrated gate drivers.

A peak current limit circuit protects against overload conditions. The undervoltage lockout (UVLO) circuit allows the input undervoltage threshold and hysteresis to be independently programmed. Other protection features include thermal shutdown and bias supply undervoltage lockout.

The LM5018 device is available in WSON-8 and SO PowerPAD-8 plastic packages.


  • Wide 7.5- to 100-V Input Range
  • Integrated 300-mA High-Side and
    Low-Side Switches
  • No Schottky Required
  • Constant On-time Control
  • No Loop Compensation Required
  • Ultra-Fast Transient Response
  • Nearly Constant Operating Frequency
  • Intelligent Peak Current Limit
  • Adjustable Output Voltage From 1.225 V
  • Precision 2% Feedback Reference
  • Frequency Adjustable to 1 MHz
  • Adjustable Undervoltage Lockout
  • Remote Shutdown
  • Thermal Shutdown
  • Packages:
    • WSON-8
    • SO PowerPAD™-8

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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
Approx. Price (US$)
LM5018 LM25011 LM5017 LM5165
7.5    6    7.5    3   
100    42    100    65   
1.25    2.51    1.25    1.23   
90    40    90    65   
0.3    2    0.65    0.15   
1    1    1    1   
50    50    50    50   
1000    2000    1000    600   
1.75    1.2    1.75    0.01   
Synchronous Rectification
UVLO Adjustable   
Adjustable Current Limit    Synchronous Rectification
UVLO Adjustable   
Adjustable Current Limit
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
Constant on-time (COT)    Constant on-time (COT)    Constant on-time (COT)    Constant on-time (COT)   
90    99    90    100   
-40 to 125    -40 to 125    -40 to 125    -40 to 150   
Catalog    Catalog    Catalog    Catalog   
MSOP-PowerPAD    SO PowerPAD
1.40 | 1ku    0.95 | 1ku    1.57 | 1ku    1.35 | 1ku   

WEBENCH® Designer LM5018

  Min   Max Range
Vin  V 9.00 to 100.00V
Vout  V 1.25 to 90.00V
Iout  A ≤ 0.3A
Ambient Temp  °C ≤ 100°C
Isolated Output