The LT3511 is a high voltage monolithic switching regulator specifically designed for the isolated flyback topology. No third winding or opto-isolator is required for regulation as the part senses output voltage directly from the primary-side flyback waveform. The device integrates a 240mA, 150V power switch, high voltage circuitry, and control into a high voltage 16-lead MSOP package with four leads removed. The LT3511 operates from an input voltage range of 4.5V to 100V and delivers up to 2.5W of isolated output power. Two external resistors and the transformer turns ratio easily set the output voltage. Off-the-shelf transformers are available for several applications. The high level of integration and the use of boundary mode operation results in a simple, clean, tightly regulated application solution to the traditionally tough problem of isolated power delivery.
The LT3511 is a monolithic high‑voltage switching regulator designed for isolated flyback topologies. It operates from a 4.5 V to 100 V input range and delivers up to 2.5 W of isolated output power while eliminating the need for an opto‑isolator or a third transformer winding.
The document provides detailed electrical characteristics, pin descriptions, block diagrams, operation principles, and package information for the 16‑lead MSOP package, enabling designers to implement the device in telecom, auxiliary, industrial, automotive and medical power supplies.
| Input Voltage Range | 4.5 V to 100 V |
|---|---|
| Maximum Switching Frequency | 650 kHz |
| Maximum Current Limit | 240 mA (typical) |
| Quiescent Current (Not Switching) | 3.5 mA |
| Operating Temperature Range | -40 °C to 150 °C |
The LT3511 operates from 4.5 V up to 100 V input.
The device can switch at up to 650 kHz.
It is supplied in a 16‑lead plastic MSOP package.
EN/UVLO is the Enable/Undervoltage Lockout pin used to start up and shut down the LT3511.