7.5-48V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator - LM25018

LM25018 (ACTIVE)

7.5-48V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator


The LM25018 device is a 48-V, 325-mA synchronous step-down regulator with integrated high-side and low-side MOSFETs. The constant on-time (COT) control scheme employed in the LM25018 device requires no loop compensation, provides excellent transient response, and enables very high 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 LM25018 device is available in WSON-8 and SO Power PAD-8 plastic packages.


  • Wide 7.5-V to 48-V Input Range
  • Integrated 325-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

View more

Parametrics Compare all products in Step-Down (Buck) Converter

Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Switching Frequency (Max) (kHz)
Switch Current Limit (Typ) (A)
Iq (Typ) (mA)
Duty Cycle (Max) (%)
Soft Start
Special Features
Control Mode
Vref Accuracy (Typ) (%)
Operating Temperature Range (C)
Approx. Price (US$)
LM25018 LM25019
7.5     7.5    
48     48    
1.25     1.25    
40     40    
0.3     0.1    
Buck     Buck    
1000     1000    
0.7     0.3    
1.75     1.75    
90     90    
None     None    
Not Needed     Not Needed    
Adjustable UVLO
Synchronous Rectification    
Adjustable UVLO
Synchronous Rectification    
Constant on-time (COT)     Constant on-time (COT)    
2     2    
Catalog     Catalog    
-40 to 125     -40 to 125    
8SO PowerPAD
8SO PowerPAD
1.12 | 1ku     0.81 | 1ku    
    Min   Max   Range  
  Vin V V    9.00 – 48.00V  
  Vout V    1.25 – 48.00V  
  Iout A    ≤ 0.325A  

  Use Isolated Output?     

  Ambient Temp °C    ≤ 100°C  
Footprint BOM Cost Efficiency
'U1 Cb Cbyp Ron Ruv1 Ruv2 L1 Rfbb Rfbt Cff Rseries Cout Cin '
What are WEBENCH® tools?
Click Here