Digital isolator technology in IGBT gate drivers yields performance & lifetime

May 20, 2015 // By Graham Prophet
Analog Devices' ADuM4135 isolated IGBT gate driver can contribute to electric motor energy efficiency, reliability and system-control performance in industrial motor control applications.

Incorporating ADI’s iCoupler digital isolator technology, the ADuM4135 ensures safety and reliability through proven galvanic isolation in a single package while delivering a combination of CMTI (common-mode transient immunity) at 100 kV/µsec and propagation delay of 50 nsec (typical).

This, says ADI, allows users to comply with IE3 and IE4 motor efficiency standards, while employing higher-frequency switching technologies for both motor control and grid-inverters. Safety features include integrated Miller clamping and desaturation detection.

The ADuM4135 gate driver’s low propagation delay and skew allows designers to to minimise dead time between low-side/high-side switching, reducing losses and improving overall system performance. The company comments that with a known, and small, propagation delay, engineers need not over-design and add margins to accommodate the variable delays associated with optocouplers. The CMTI performance and low propagation delay also support new power switch technologies, including SiC and GaN, which can use higher switching frequencies in systems with increased transients. The ADuM4135 is available in a 16-lead, wide-body SOIC package and provides 8-mm creepage and clearance.

Features include;

4A peak drive output capability

Output power device resistance < 1 Ohm

Desaturation protection

Isolated desaturation fault reporting

Soft-shutdown on fault

Miller clamp output with gate sense input

Isolated fault and ready functions

Low propagation delay (50 nsec typical)/ delay skew (15 nsec typical)

In a 16 lead wide-body SOIC, the AduM4135 costs $2.26 (1000)'

Analog Devices;