OUT

ISO5451

ISO5451

www.ti.com

SLLSEO1B – JUNE 2015 – REVISED DECEMBER 2015

9 Detailed Description

9.1 Overview

The ISO5451 is an isolated gate driver for IGBTs and MOSFETs. Input CMOS logic and output power stage are

The IO circuitry on the input side interfaces with a micro controller and consists of gate drive control and RESET

(RST) inputs, READY (RDY) and FAULT (FLT) alarm outputs. The power stage consists of power transistors to

supply 2.5-A pull-up and 5-A pull-down currents to drive the capacitive load of the external power transistors, as

well as DESAT detection circuitry to monitor IGBT collector-emitter overvoltage under short circuit events. The

capacitive isolation core consists of transmit circuitry to couple signals across the capacitive isolation barrier, and

receive circuitry to convert the resulting low-swing signals into CMOS levels. The ISO5451 also contains under

voltage lockout circuitry to prevent insufficient gate drive to the external IGBT, and active output pull-down

feature which ensures that the gate-driver output is held low, if the output supply voltage is absent. The ISO5451

also has an active Miller clamp which can be used to prevent parasitic turn-on of the external power transistor,

due to Miller effect, for unipolar supply operation.

9.2 Functional Block Diagram

Copyright © 2015, Texas Instruments Incorporated

Submit Documentation Feedback

15

Product Folder Links: ISO5451