LM3485

ACTIVE

4.5-35V, Hysteretic Non-Synchronous PFET Buck Controller

Top

Product details

Parameters

Vin (Min) (V) 4.5 Vin (Max) (V) 35 Vout (Min) (V) 1.242 Vout (Max) (V) 35 Iout (Max) (A) 4 Iq (Typ) (uA) 250 Switching frequency (Min) (kHz) 50 Switching frequency (Max) (kHz) 1000 Features Enable Operating temperature range (C) -40 to 125 Regulated outputs (#) 1 Number of Phases 1 Rating Catalog open-in-new Find other Buck controllers (external switch)

Package | Pins | Size

VSSOP (DGK) 8 15 mm² 3 x 4.9 open-in-new Find other Buck controllers (external switch)

Features

  • Easy-to-Use Control Methodology
  • No Control-Loop Compensation Required
  • 4.5-V to 35-V Wide Input Range
  • 1.242-V to VIN Adjustable Output Range
  • High Efficiency 93%
  • ±1.3% (±2% Over Temp) Internal Reference
  • 100% Duty Cycle
  • Maximum Operating Frequency > 1 MHz
  • Current Limit Protection
open-in-new Find other Buck controllers (external switch)

Description

The LM3485 is a high-efficiency PFET switching regulator controller that can be used to quickly and easily develop a small, low-cost, switching buck regulator for a wide range of applications. The hysteretic control architecture provides for simple design without any control-loop stability concerns using a wide variety of external components. The PFET architecture also allows for low component count as well as ultralow dropout, 100% duty cycle operation. Another benefit is high efficiency operation at light loads without an increase in output ripple.

Current limit protection is provided by measuring the voltage across the RDS(ON) of the PFET, thus eliminating the need for a sense resistor. The cycle-by-cycle current limit can be adjusted with a single resistor, ensuring safe operation over a range of output currents.

open-in-new Find other Buck controllers (external switch)
Download

Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 6
Type Title Date
* Datasheet LM3485 Hysteretic PFET Buck Controller datasheet (Rev. H) Dec. 28, 2015
Selection guide Power Management Guide 2018 (Rev. R) Jun. 25, 2018
Selection guide Control-Mode Quick Reference Guide (Rev. A) Sep. 14, 2017
Application note Reduce buck-converter EMI and voltage stress by minimizing inductive parasitics Jul. 21, 2016
User guide AN-1227 LM3485 Evaluation Board (Rev. B) Apr. 25, 2013
User guide AN-1392 LM3485 LED Demo Board (Rev. B) Apr. 25, 2013

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

EVALUATION BOARD Download
document-generic User guide
25
Description

Hysteretic PFET Buck Controller

Features
  • Easy to use control methodology
  • No control loop compensation required
  • 4.5V to 35V wide input range
  • 1.242V to VIN adjustable output range
  • High efficiency 93%
  • +1.3% ( +2% over temp) internal reference
  • 100% duty cycle
  • Maximum operating frequency > 1MHz
  • Current limit protection
  • MSOP-8

Applications:

  • Set-Top Box
  • (...)
EVALUATION BOARD Download
document-generic User guide
25
Description

The LM3485 LED driver board is a buck regulator derived controlled current source designed to drive high power, high brightness LEDs (HBLEDs) such as the Luxeon™ Emitter at dissipations of 1W to 5W. The board can accept an input voltage ranging from 5V to 30V and can control the output current (...)

Design tools & simulation

SIMULATION MODEL Download
SNVM296.ZIP (44 KB) - PSpice Model
SIMULATION MODEL Download
SNVM716.ZIP (2 KB) - PSpice Model
SIMULATION TOOL Download
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — 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 (...)
Features
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)

CAD/CAE symbols

Package Pins Download
VSSOP (DGK) 8 View options

Ordering & quality

Information included:
  • RoHS
  • REACH
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring

Recommended products may have parameters, evaluation modules or reference designs related to this TI product.

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​

Videos