LT1683 - Slew Rate Controlled Ultralow Noise Push-Pull DC/DC Controller

The LT1683 is a switching regulator controller designed to lower conducted and radiated electromagnetic interference (EMI). Ultralow noise and EMI are achieved by controlling the voltage and current slew rates of external N-channel MOSFET switches. Current and voltage slew rates can be independently set to optimize harmonic content of the switching waveforms vs efficiency. The LT1683 can reduce high frequency harmonic power by as much as 40dB with only minor losses in efficiency.

The LT1683 utilizes a dual output (push-pull) current mode architecture optimized for low noise topologies. The IC includes gate drivers and all necessary oscillator, control and protection circuitry. Unique error amp circuitry can regulate both positive and negative voltages. The oscillator may be synchronized to an external clock for more accurate placement of switching harmonics.

Protection features include gate drive lockout for low VIN, opposite gate lockout, soft-start, output current limit, short-circuit current limiting, gate drive overvoltage clamp and input supply undervoltage lockout.

Features
  • Greatly Reduced Conducted and Radiated EMI
  • Low Switching Harmonic Content
  • Independent Control of Output Switch Voltage and Current Slew Rates
  • Greatly Reduced Need for External Filters
  • Dual N-Channel MOSFET Drivers
  • 20kHz to 250kHz Oscillator Frequency
  • Easily Synchronized to External Clock
  • Regulates Positive and Negative Voltages
  • Easier Layout Than with Conventional Switchers
Typical Application

Applications
  • Power Supplies for Noise Sensitive Communication Equipment
  • EMI Compliant Offline Power Supplies
  • Precision Instrumentation Systems
  • Isolated Supplies for Industrial Automation
  • Medical Instruments
  • Data Acquisition Systems
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT1683EG#PBFSSOP-20E$5.62$4.75
LT1683EG#TRPBFSSOP-20E$4.85
LT1683IG#PBFSSOP-20I$7.34$6.20
LT1683IG#TRPBFSSOP-20I$6.30
Demo Boards
Part NumberDescriptionPrice
DC477ALT1683EG | Low Noise/EMI Switching Power Supply, 36V to 72Vin, 5Vout @ 2A$125.00
Datasheet
Application Note
Reliability Data
LT Journal
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R303 Reliability Data
Feb 2001 Reduce EMI with Ultralow Noise 48V to 5V, 10W DC/DC Converter
Sep 2001 Two New Switching Regulators Deliver Both Power and Ultralow Noise
LT1683 Footprints and Symbols