DESCRIPTION
The LTC®1871-1 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. It eliminates the need for a current sense resistor by utilizing the power MOSFET’s on-resistance, thereby maximizing efficiency. Higher output voltage applications are possible with the LTC1871-1 by connecting the SENSE pin to a resistor in the source of the power MOSFET.

FEATURES
■ High Effi ciency (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
■ Ultra Low Pulse Skip Threshold for Wide Input
   Range Applications
■ 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

APPLICATIONS
■ Telecom Power Supplies
■ Portable Electronic Equipment