LTC1871 - Wide Input Range, No RSENSE Current Mode Boost, Flyback and SEPIC Controller

Features

  • High Efficiency (No Sense Resistor Required)
  • Wide Input Voltage Range: 2.5V to 36V
  • Current Mode Control Provides Excellent Transient Response
  • High Maximum Duty Cycle (92% Typ)
  • ±2% RUN Pin Threshold with 100mV Hysteresis
  • ±1% Internal Voltage Reference
  • Micropower Shutdown: IQ = 10μA
  • Programmable Operating Frequency (50kHz to 1MHz) with One External Resistor
  • Synchronizable to an External Clock Up to 1.3 × fOSC
  • User-Controlled Pulse Skip or Burst Mode® Operation
  • Internal 5.2V Low Dropout Voltage Regulator
  • Output Overvoltage Protection
  • Capable of Operating with a Sense Resistor for High Output Voltage Applications
  • Small 10-Lead MSOP Package

Typical Application

LTC1871 Typical Application
LTC1871 Typical Application

Description

The LTC1871 is a wide input range, current mode, boost, flyback or SEPIC controller that drives an N-channel power MOSFET and requires very few external components. Intended for low to medium power applications, it eliminates the need for a current sense resistor by utilizing the power MOSFET’s on-resistance, thereby maximizing efficiency.

The IC’s operating frequency can be set with an external resistor over a 50kHz to 1MHz range, and can be synchronized to an external clock using the MODE/SYNC pin. Burst Mode operation at light loads, a low minimum operating supply voltage of 2.5V and a low shutdown quiescent current of 10μA make the LTC1871 ideally suited for battery-operated systems.

For applications requiring constant frequency operation, Burst Mode operation can be defeated using the MODE/ SYNC pin. Higher output voltage boost, SEPIC and flyback applications are possible with the LTC1871 by connecting the SENSE pin to a resistor in the source of the power MOSFET.

The LTC1871 is available in the 10-lead MSOP package.

  Vin Range INTVcc Features
LTC1871 2.5V to 36V 5.2V -
LTC1871-1 2.5V to 36V 5.2V Lower Burst Mode Threshold (0.195V vs. 0.3V)
LTC1871-7 6V to 36V 7V Drives 6V Gate N-Channel MOSFETs

Packaging

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

MS-10

LTC1871 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LTC1871EMS MSOP 10 E $3.14 $2.65 View
LTC1871EMS#PBF MSOP 10 E $3.14 $2.65 View
LTC1871EMS#TR MSOP 10 E $2.71 View
LTC1871EMS#TRPBF MSOP 10 E $2.71 View
LTC1871EMS-1#PBF MSOP 10 E $3.14 $2.65 View
LTC1871EMS-1#TRPBF MSOP 10 E $2.71 View
LTC1871EMS-7 MSOP 10 E $3.14 $2.65 View
LTC1871EMS-7#PBF MSOP 10 E $3.14 $2.65 View
LTC1871EMS-7#TR MSOP 10 E $2.71 View
LTC1871EMS-7#TRPBF MSOP 10 E $2.71 View
LTC1871HMS MSOP 10 H $4.83 $3.38 View
LTC1871HMS#PBF MSOP 10 H $4.83 $3.38 View
LTC1871HMS#TRPBF MSOP 10 H $3.44 View
LTC1871IMS MSOP 10 I $4.38 $3.05 View
LTC1871IMS#PBF MSOP 10 I $4.38 $3.05 View
LTC1871IMS#TR MSOP 10 I $3.11 View
LTC1871IMS#TRPBF MSOP 10 I $3.11 View
LTC1871IMS-1#PBF MSOP 10 I $4.38 $3.05 View
LTC1871IMS-1#TRPBF MSOP 10 I $3.11 View
LTC1871IMS-7 MSOP 10 I $4.38 $3.05 View
LTC1871IMS-7#PBF MSOP 10 I $4.38 $3.05 View
LTC1871IMS-7#TR MSOP 10 I $3.11 View
LTC1871IMS-7#TRPBF MSOP 10 I $3.11 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
DC414A LTC1871EMS | High Efficiency Boost Converter, 3.3V Input, 5.0Vout @ 7Amp $125.00
DC415A LTC1871EMS | High Efficiency SEPIC Converter, 5V-15V Input, 12Vout @ 2Amp $125.00
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Applications

  • Telecom Power Supplies
  • Portable Electronic Equipment

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Design Tools

LTspiceIV

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Models for the following parts are available in LTspice IV:
LTC1871
LTC1871-1
LTC1871-7

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