10 November 2011

CISSOID releases HADES high-temperature, high-reliability isolated gate driver for high-density power converters

Fabless high-temperature semiconductor firm CISSOID of Mont-Saint-Guibert, Belgium has launched HADES, the first isolated gate driver solution designed to drive high-temperature power transistors, specifically (but not exclusively) silicon carbide (SiC) and gallium nitride (GaN) fast-switching devices.

With HADES, it is claimed, system engineers can develop power converters that are five times smaller and lighter than before, with better efficiency, and get power converters able to operate in a high-temperature ambient, if required. No matter what the ambient temperature is, the system’s life-time will be an order of magnitude longer than traditional solutions, it is reckoned.

HADES has been designed to drive SiC power transistors, which have low switching losses. It can switch them at high frequencies, which allows passive and magnetic components to be smaller and lighter. Furthermore, due to its ability to sustain high temperatures, HADES can be located next to the power transistors, which reduces parasitic capacitances and inductances, further improving the associated losses and delays in the system.

HADES is a reference design and an evaluation board delivered with full documentation. It can drive two SiC MOSFET power switches on a DC bus voltage up to 1200V. The reference design is scalable up to +/-20A gate current, while the evaluation board features +/-4A. A specific variant of board for normally-on JEFTs will also be available, and other types of switching devices (normally-on/off JFETs, BJTs and IGBTs) can be supported with minor changes.

As an example, HADES’ operation and performance were demonstrated in a 3kW Buck DC-DC converter, driving SiC MOSFETs, at 175°C ambient and switching at 150kHz, with rise times of less than 25ns. In these operating conditions, HADES, which has been designed for high dV/dt immunity (50kV/μs) and IC junction temperatures up to 225°C, runs with comfortable safety margins, says CISSOID.

In terms of efficiency, the combination of HADES with the newest SiC switches in advanced power converter topologies should bring efficiencies in excess of 98%, even at switching frequencies above 100kHz.

The HADES gate driver suits high-power converters such as motor drives, battery chargers and power distribution used in applications like railways, aircraft, renewable energy and hybrid/electric vehicles (HEV). It delivers high power density, simplified cooling and high reliability. The fast-switching ability of HADES, plus the fact that it can operate reliably at the same temperature as the switches (200°C junction and above), suits the new generation of intelligent power modules (IPM), says CISSOID.

HADES is built from CISSOID’s chipset CHT-THEMIS, CHT-ATLAS and CHT-RHEA. With its on-board isolated power supply based on CISSOID’s PWM controller CHT-MAGMA and derived from STROMBOLI technology, HADES requires a single +12V supply. All HADES’ active components are guaranteed for normal operation over the full temperature range og -55°C to +225°C. The magnetic isolation of the power supply also sustains reliably high temperatures, as opposed to optocouplers.

On-board protection functions include under voltage lockout (UVLO) and desaturation detection, which monitors the drain-to-source voltage of the power transistor to detect over-currents. The board also implements an active Miller clamping function, which prevents parasitic turn-on due to the Miller capacitor of the power switch.

The evaluation kit (EVK-HADES) is available now, priced at €7500.

Tags: CISSOID SiC switches SiC GaN switches

Visit: www.cissoid.com