LT1171 - 100kHz, 5A, 2.5A and 1.25A High Efficiency Switching Regulators

Features

  • Wide Input Voltage Range: 3V to 60V
  • Low Quiescent Current: 6mA
  • Internal 5A Switch
    (2.5A for LT1171, 1.25A for LT1172)
  • Shutdown Mode Draws Only 50μA Supply Current
  • Very Few External Parts Required
  • Self-Protected Against Overloads
  • Operates in Nearly All Switching Topologies
  • Flyback-Regulated Mode Has Fully Floating Outputs
  • Comes in Standard 5-Pin Packages
  • LT1172 Available in 8-Pin MiniDIP and Surface Mount Packages
  • Can Be Externally Synchronized

Typical Application

LT1171 Typical Application
LT1171 Typical Application

Description

The LT®1170/LT1171/LT1172 are monolithic high power switching regulators. They can be operated in all standard switching configurations including buck, boost, flyback, forward, inverting and “Cuk.” A high current, high efficiency switch is included on the die along with all oscillator, control and protection circuitry. Integration of all functions allows the LT1170/LT1171/LT1172 to be built in a standard 5-pin TO-3 or TO-220 power package as well as the 8-pin packages (LT1172). This makes them extremely easy to use and provides “bust proof” operation similar to that obtained with 3-pin linear regulators.

The LT1170/LT1171/LT1172 operate with supply voltages from 3V to 60V, and draw only 6mA quiescent current. They can deliver load power up to 100W with no external power devices. By utilizing current-mode switching techniques, they provide excellent AC and DC load and line regulation.

The LT1170/LT1171/LT1172 have many unique features not found even on the vastly more difficult to use low power control chips presently available. They use adaptive antisat switch drive to allow very wide ranging load currents with no loss in efficiency. An externally activated shutdown mode reduces total supply current to 50μA typically for standby operation.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

N-8, J8, SO-8, SW-16, T5, DD-5

LT1171 Package Drawing
LT1171 Package Drawing
LT1171 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LT1171CQ DD PAK 5 C $6.25 $5.05 View
LT1171CQ#PBF DD PAK 5 C $6.25 $5.05 View
LT1171CQ#TR DD PAK 5 C $5.17 View
LT1171CQ#TRPBF DD PAK 5 C $5.17 View
LT1171CT TO-220 5 C $5.75 $4.60 View
LT1171CT#06PBF TO-220 5 C $5.75 $4.60 View
LT1171CT#PBF TO-220 5 C $5.75 $4.60 View
LT1171HVCQ DD PAK 5 C $7.35 $6.25 View
LT1171HVCQ#PBF DD PAK 5 C $7.35 $6.25 View
LT1171HVCQ#TR DD PAK 5 C $6.37 View
LT1171HVCQ#TRPBF DD PAK 5 C $6.37 View
LT1171HVCT TO-220 5 C $7.50 $6.00 View
LT1171HVCT#30PBF TO-220 5 C $7.95 $6.45 View
LT1171HVCT#PBF TO-220 5 C $7.50 $6.00 View
LT1171HVIQ DD PAK 5 I $8.82 $7.50 View
LT1171HVIQ#PBF DD PAK 5 I $8.82 $7.50 View
LT1171HVIQ#TR DD PAK 5 I $7.62 View
LT1171HVIQ#TRPBF DD PAK 5 I $7.62 View
LT1171HVIT TO-220 5 I $9.00 $7.20 View
LT1171HVIT#PBF TO-220 5 I $9.00 $7.20 View
LT1171IQ DD PAK 5 I $6.10 $5.15 View
LT1171IQ#PBF DD PAK 5 I $6.10 $5.15 View
LT1171IQ#TR DD PAK 5 I $5.27 View
LT1171IQ#TRPBF DD PAK 5 I $5.27 View
LT1171IT TO-220 5 I $7.50 $6.10 View
LT1171IT#PBF TO-220 5 I $7.50 $6.10 View
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC139A-A LT1171CQ | SUBSCRIBER LINE INTERFACE CKT POWER SUPPLY S.M. TRANSFORMER $100.00
DC139A-B LT1171CQ | SUBSCRIBER LINE INTERFACE CKT POWER SUPPLY T.H. TRANSFORMER $100.00
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Click here to view our complete list of demo boards

Applications

  • Logic Supply 5V at 10A
  • 5V Logic to ±15V Op Amp Supply
  • Battery Upconverter
  • Power Inverter (+ to –) or (– to +)
  • Fully Floating Multiple Outputs
USER NOTE:
This data sheet is only intended to provide specifications, graphs, and a general functional description of the LT1170/LT1171/LT1172. Application circuits are included to show the capability of the LT1170/LT1171/LT1172. A complete design manual (AN19) should be obtained to assist in developing new designs. This manual contains a comprehensive discussion of both the LT1070 and the external components used with it, as well as complete formulas for calculating the values of these components. The manual can also be used for the LT1170/LT1171/LT1172 by factoring in the higher frequency. A CAD design program called SwitcherCAD® is also available.

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Simulate

LTspice IV is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. To download LTspice IV and other FREE simulation tools, please visit our Design Simulation page.

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Related models available in LTspice IV
LT1171
LT1171HV

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