Product details

Vin (Min) (V) 4.5 Vin (Max) (V) 75 Vout (Min) (V) 1.25 Vout (Max) (V) 75 Iout (Max) (A) 10 Iq (Typ) (uA) 1300 Switching frequency (Min) (kHz) 50 Switching frequency (Max) (kHz) 1000 Features Adjustable Current Limit, Enable, Frequency Synchronization Regulated outputs (#) 1 Number of phases 1 Rating Catalog
Vin (Min) (V) 4.5 Vin (Max) (V) 75 Vout (Min) (V) 1.25 Vout (Max) (V) 75 Iout (Max) (A) 10 Iq (Typ) (uA) 1300 Switching frequency (Min) (kHz) 50 Switching frequency (Max) (kHz) 1000 Features Adjustable Current Limit, Enable, Frequency Synchronization Regulated outputs (#) 1 Number of phases 1 Rating Catalog
HVSSOP (DGN) 8 9 mm² 3 x 3 VSSOP (DGK) 8 15 mm² 3 x 4.9 WSON (NGQ) 8 9 mm² 3 x 3
  • LM5085-Q1 is an Automotive Grade Product that
    is AEC-Q100 Grade 1 Qualified (–40°C to 125°C
    Operating Junction Temperature)
  • Wide 4.5-V to 75-V Input Voltage Range
  • Adjustable Current Limit Using RDS(ON) or a
    Current Sense Resistor
  • Programmable Switching Frequency to 1MHz
  • No Loop Compensation Required
  • Ultra-Fast Transient Response
  • Nearly Constant Operating Frequency with Line
    and Load Variations
  • Adjustable Output Voltage from 1.25 V
  • Precision ±2% Feedback Reference
  • Capable of 100% Duty Cycle Operation
  • Internal Soft-start Timer
  • Integrated High Voltage Bias Regulator
  • Thermal Shutdown
  • Package:
    • HVSSOP-8
    • VSSOP-8
    • WSON-8
  • LM5085-Q1 is an Automotive Grade Product that
    is AEC-Q100 Grade 1 Qualified (–40°C to 125°C
    Operating Junction Temperature)
  • Wide 4.5-V to 75-V Input Voltage Range
  • Adjustable Current Limit Using RDS(ON) or a
    Current Sense Resistor
  • Programmable Switching Frequency to 1MHz
  • No Loop Compensation Required
  • Ultra-Fast Transient Response
  • Nearly Constant Operating Frequency with Line
    and Load Variations
  • Adjustable Output Voltage from 1.25 V
  • Precision ±2% Feedback Reference
  • Capable of 100% Duty Cycle Operation
  • Internal Soft-start Timer
  • Integrated High Voltage Bias Regulator
  • Thermal Shutdown
  • Package:
    • HVSSOP-8
    • VSSOP-8
    • WSON-8

The LM5085 is a high efficiency PFET switching regulator controller that can be used to quickly and easily develop a small, efficient buck regulator for a wide range of applications. This high voltage controller contains a PFET gate driver and a high voltage bias regulator which operates over a wide 4.5-V to 75-V input range. The constant on-time regulation principle requires no loop compensation, simplifies circuit implementation, and results in ultrafast load transient response. The operating frequency remains nearly constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The PFET architecture allows 100% duty cycle operation for a low dropout voltage. Either the RDS(ON) of the PFET or an external sense resistor can be used to sense current for over-current detection.

The LM5085 is a high efficiency PFET switching regulator controller that can be used to quickly and easily develop a small, efficient buck regulator for a wide range of applications. This high voltage controller contains a PFET gate driver and a high voltage bias regulator which operates over a wide 4.5-V to 75-V input range. The constant on-time regulation principle requires no loop compensation, simplifies circuit implementation, and results in ultrafast load transient response. The operating frequency remains nearly constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The PFET architecture allows 100% duty cycle operation for a low dropout voltage. Either the RDS(ON) of the PFET or an external sense resistor can be used to sense current for over-current detection.

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Design & development

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Evaluation board

LM5085EVAL — LM5085 - 75V Wide Vin Constant On-Time PFET Buck Switching Controller Evaluation Module

The LM5085 evaluation board provides the design engineer with a fully functional buck regulator, employing the LM5085 PFET switching controller which uses the constant on-time (COT) operating principle. The evaluation board provides a 5V output over an input range of 5.5V to 55V. The circuit (...)

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Simulation model

LM5085 PSpice Transient Model (Rev. A) LM5085 PSpice Transient Model (Rev. A)

Simulation model

LM5085 PSpice Unencrypted Transient Model (Rev. B) LM5085 PSpice Unencrypted Transient Model (Rev. B)

Simulation model

LM5085 TINA-TI Load Transient Reference Design (Rev. A) LM5085 TINA-TI Load Transient Reference Design (Rev. A)

Simulation model

LM5085 TINA-TI Startup Reference Design (Rev. A) LM5085 TINA-TI Startup Reference Design (Rev. A)

Simulation model

LM5085 TINA-TI Transient Spice Model (Rev. A) LM5085 TINA-TI Transient Spice Model (Rev. A)

Simulation model

LM5085 Unencrypted PSpice Transient Model LM5085 Unencrypted PSpice Transient Model

Simulation tool

PSPICE-FOR-TI PSpice® for TI design and simulation tool

PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Calculation tool

LM25085-5085QUICK-CALC LM(2)5085 Quick Start Calculator

Reference designs

PMP9103 — Low Cost Buck Provides 24V@2A from 32Vin for Wireless Base Station Reference Design

This hysteretic buck converter delivers greater than 97% efficiency, low cost and small area. Additional benefits are very low output ripple voltage and excellent load transient response.
Package Pins Download
HVSSOP (DGN) 8 View options
VSSOP (DGK) 8 View options
WSON (NGQ) 8 View options

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