The LTC ®1871 is a wide input range, current mode, boost, flyback or SEPIC controller that drives an N-channel power MOSFET and requires very few external compo- nents.
The LTC1871 controller provides a high‑efficiency solution for boost, flyback and SEPIC converters without requiring a sense resistor. It operates over a 2.5 V to 36 V input range, offers a programmable 50 kHz‑1 MHz operating frequency, and includes an internal 5.2 V low‑dropout regulator.
Typical applications include telecom power supplies and portable electronic equipment. The device is supplied in a 10‑lead MSOP package and features a 92 % typical maximum duty cycle, micropower shutdown, and over‑voltage protection.
| Input Voltage Range | 2.5 V to 36 V |
|---|---|
| Maximum Duty Cycle | 92 % typ |
| Shutdown Current | 10 pA |
| Operating Frequency Range | 50 kHz to 1 MHz |
| Internal Regulator Output | 5.2 V |
| Package Type | 10‑Lead MSOP |
| Absolute Maximum Vin | -0.3 V to 36 V |
The controller operates from 2.5 V up to 36 V input.
It uses the MOSFET’s on‑resistance via the SENSE pin to measure current.
The shutdown current is typically about 10 µA.