IGBT driver IC provides protection for inverters and motor drives

September 12, 2016 // By Graham Prophet
Silicon Labs’ Si828x ISOdriver family provides advanced monitoring features for IGBT switches in high-voltage industrial and green energy applications.

The expanded ISOdriver portfolio gains a family of isolated gate drivers designed to protect sensitive insulated-gate bipolar transistor (IGBT) switches in power inverter and motor drive applications. ISOdriver ICs provide isolation of 5 kVrms withstand), integrated features including an optional dc-dc converter, fastest desaturation detection, superior timing characteristics, and noise and transient immunity.

Intended for industrial motor drives, solar inverters, high-voltage power converters, uninterruptable power supplies, and heating, ventilation and air conditioning (HVAC) compressor control, in which systems can be expected to last more than 25 years while operating in harsh environments, isolators can be first points of failure and lifetime-limiting devices in these systems. Traditional optocoupler-based isolators, Silabs asserts, have significant limitations in temperature range, noise immunity and product lifetime. Based on CMOS isolation technology, Si828x gate drivers can operate over a full industrial temperature range, support product lifetimes of up to 100 years, and meet UL, VDE, CQC and CSA standards.

The Si828x family combines isolation, advanced gate driver technology and fast over-current monitoring in a single, cost-effective device designed to protect costly IGBT switches. The defining Si828x feature is a 4A gate driver coupled with desaturation detection to monitor the IGBT for over-current. In that event, the Si828x driver initiates a controlled shutdown of the switch while updating the controller with the fault status, protecting the IGBT and the system. Additional integrated features include split outputs, a Miller clamp to prevent parasitic gate turn-on, and driver power state and fault feedback to the controller.

The Si828x family includes driver versions with an integrated isolated dc-dc converter, which helps developers simplify the layout, reduce component count and board size, and ease the complexity of creating and managing multiple power domains. A single power bus can be routed across the system, eliminating complex spacing concerns. Localizing power supplies to each driver reduces inductance, minimizes noise and removes transients.