LTC1871-7 Series

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

Catalog

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

Part	Voltage - Supply (Vcc/Vdd) [Min]	Voltage - Supply (Vcc/Vdd) [Max]	Package / Case	Package / Case [x]	Package / Case [x]	Mounting Type	Topology	Duty Cycle (Max) [Max]	Function	Supplier Device Package	Output Configuration	Control Features	Output Type	Operating Temperature [Min]	Operating Temperature [Max]	Frequency - Switching [Min]	Frequency - Switching [Max]	Number of Outputs	Output Phases
Analog Devices LTC1871IMS#TRPBF	2.5 V	36 V	10-MSOP 10-TFSOP	3 mm	0.118 in	Surface Mount	Boost Flyback SEPIC	92 %	Step-Up Step-Up/Step-Down	10-MSOP	Positive or Negative	Enable Frequency Control	Transistor Driver	-40 °C	125 ¯C	50 kHz	1 MHz	1	1
Analog Devices LTC1871IMS-7	6 V	36 V	10-MSOP 10-TFSOP	3 mm	0.118 in	Surface Mount	Boost Flyback SEPIC	92 %	Step-Up Step-Up/Step-Down	10-MSOP	Positive	Enable Frequency Control	Transistor Driver	-40 °C	125 ¯C	50 kHz	1 MHz	1	1
Analog Devices LTC1871EMS-7#TRPBF	6 V	36 V	10-MSOP 10-TFSOP	3 mm	0.118 in	Surface Mount	Boost Flyback SEPIC	92 %	Step-Up Step-Up/Step-Down	10-MSOP	Positive	Enable Frequency Control	Transistor Driver	-40 °C	85 °C	50 kHz	1 MHz	1	1
Analog Devices LTC1871EMS-1#TRPBF	2.5 V	36 V	10-MSOP 10-TFSOP	3 mm	0.118 in	Surface Mount	Boost Flyback SEPIC	92 %	Step-Up Step-Up/Step-Down	10-MSOP	Positive or Negative	Enable Frequency Control	Transistor Driver	-40 °C	85 °C	50 kHz	1 MHz	1	1
Analog Devices LTC1871EMS#TRPBF	2.5 V	36 V	10-MSOP 10-TFSOP	3 mm	0.118 in	Surface Mount	Boost Flyback SEPIC	92 %	Step-Up Step-Up/Step-Down	10-MSOP	Positive or Negative	Enable Frequency Control	Transistor Driver	-40 °C	85 °C	50 kHz	1 MHz	1	1

Catalog

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

Key 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

• 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

Description

The LTC1871-1 is a wide input range, current mode, boost, flyback or SEPIC controller that drives an Nchannel 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.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.The LTC1871-1 differs from the LTC1871 by having a lower pulse skip threshold, making it ideal for applications requiring constant frequency operation at light loads. The lower pulse skip threshold also helps maintain constant frequency operation in applications with a wide input voltage range. For applications requiring primary-to-secondary side isolation, please refer to the LTC1871 datasheet.The LTC1871-1 is available in the 10-lead MSOP package.Vin RangeINTVccFeaturesLTC18712.5V to 36V5.2V-LTC1871-12.5V to 36V5.2VLower Burst Mode Threshold (0.195V vs. 0.3V)LTC1871-76V to 36V7VDrives 6V Gate N-Channel MOSFETsLTC1871X2.5V to 36V5.2V175°C Junction Temp, 100% Tested at 175°CApplicationsTelecom Power SuppliesPortable Electronic Equipment