The LT1680 is a high power, current mode switching power supply controller optimized for boost topologies. The IC drives N-channel MOSFET switches for DC/DC converters in applications up to 60V input. A high current gate drive output handles up to 10,000pF gate capacitance, enabling the construction of high power DC/DC converters. Current sense common mode range up to 60V allows current sensing to be referenced to the input supply, eliminating the need for sense blanking circuits. The LT1680 incorporates programmable average current limiting allowing accurate limiting of DC current in the magnetics, independent of ripple current. User adjustable slope compensation provides stable operation at duty cycles up to 90%. The LT1680 operating frequency is programmable and can be synchronized up to 200kHz. Minimum off-time operation provides switch protection. The IC also incorporates a soft start feature that is gated by both shutdown and undervoltage lockout conditions.
The LT1680 is a high‑power, current‑mode switching controller designed for boost topologies up to 60 V input. It features programmable average current limiting, a 5 V reference output capable of 10 mA, and a synchronizable oscillator up to 200 kHz.
The document provides detailed electrical characteristics, pin descriptions, typical performance curves, package dimensions for both PDIP and SOIC versions, and example circuits for 5 V‑to‑48 V boost converters.
| Maximum Input Voltage | 60 V |
|---|---|
| Maximum Oscillator Frequency | 200 kHz |
| 5 V Reference Output Current | 10 mA |
| Gate Drive Capacitance | 10,000 pF |
The controller can operate up to 200 kHz.
The falling threshold is about 9 V and the rising threshold about 9.35 V, with a hysteresis of roughly 350 mV.
The device is available in 16‑lead packages.
The bandgap reference is 1.25 V.