Reinhard Herzer

Method for electrical detection of bond wire lift-off for power semiconductors

A novel approach is presented for detecting bond wire lift-off in power semiconductor devices while they are in operation. The aim is to improve the reliability of power electronic systems. The method comprises a specific bond assembly and an integrated subcircuit as part of the gate driver, and serves to detect bond wire lift-off in parallel switched power devices, a typical end-of-life phenomenon encountered in modules, which results in loss of contact and therefore of controllability. The former is detected and the system is prevented from going abruptly into failure mode, so that the destruction of devices is safely avoided.

600V SOI gate drive HVIC for medium power applications operating up to 200/spl deg/C

The design, functionality and measurements of a fully integrated 600V SOI gate drive IC are presented. The seven-channel HVIC is aimed at three-phase systems for low power and medium power applications. Dielectric device isolation and detailed circuit design ensure operation up to a temperature of 200/spl deg/C. Robust signal processing has been given highest attention at all design stages. A dedicated signal reconstruction topology is presented to provide maximum immunity against parasitic coupling from the power plane. The measurements confirming the safe operation of the IC are given.

Application of carrier lifetime control by irradiation to 1.2kV NPT IGBTs

Device simulation, based on an extended recombination model and previously determined recombination center parameters, serves as design tool for carrier-lifetime controlled, state-of-the-art 1.2kV NPT IGBTs. Homogenous and local recombination center profiles are considered. The sensitivity of important device characteristics to the type of the recombination center profile is investigated in simulation and experiment. A possible application, the improvement of reverse leakage properties of reverse blocking capable NPT IGBTs, is discussed.

Analysis of dynamic impatt oscillations caused by radiation induced deep centers

The occurrence of high-frequency impatt oscillations is related to the presence of charged deep donor-states as generated by irradiation processes for carrier-lifetime control. This effect is well-known in electron-radiated devices. Device simulation predicts a similar effect in locally lifetime-controlled helium-radiated devices. The experiment gives an approval of the simulation results but shows some unexpected effects too.

IGBT driver chipset for high power applications

Power electronics systems in the 600 V to 1700 V range are commonly used in motor drive, power supply and power conversion applications. An integrated chipset is presented for application in IGBT high power systems. It has flexible controller ICs on the primary side and strong driver ICs on the secondary side. The whole system is arranged so that pulse transformers provide physical potential separation and the voltage is scalable between 600 V and 1700 V at currents from 20 A up to 3000 A. The option to use opto-couplers and fiber optics instead of pulse transformers extends the chipsets applicability.

IGBT driver chip set with advanced digital signal processing

This article describes a new approach to control and drive electronic power switches (such as IGBTs). It uses two ASICs — one on the primary (control) side of the driver and one on the secondary (power) side of it. Both chips exchange control and status signals with each other across the insulation barrier between both sides. The system on the power side digitizes all analog sensor inputs (such as the temperature, DC-link voltage, VCEsat voltage) and transmits this data and other status information to the control side. The other way round, the primary side sends repetitive and differential control signals to the power side. To achieve the required data rates across the insulation barrier, the characteristics of the physical layer are improved. As a result, this new topology greatly improves the protection of the control (primary and client) side in case of a fatal failure of the power side of the system.

Integrated SOI gate driver for 1200V SiC-FET switches

Novel gate driver ICs for the control of 1200V SiC-JFET and -MOSFET half bridges based on high voltage silicon on insulator (SOI) technology are presented. The driver ICs features an extended gate voltage range of 20V and due to an innovative level shifter concept the output voltage levels for turn-off and turn-on can be changed in a wide voltage range between -20V...0V and 0V...+20V. The two dies of this multi-chip solution are assembled in a tiny cost effective IC package with excellent electrical and thermal properties. The measurement results demonstrate the driver performance at high voltage switching and power inverter operation. The new driver approach supports the market needs for cost efficient gate driver circuits for SiC devices.

High power, high frequency SiC-MOSFET system with outstanding performance, power density and reliability

The paper presents the benefit of an optimized gate drive which can be achieved with a new generation of very low inductive 1200V, 400A SiC-MOSFET half bridge module and a new and adapted gate driver. After presenting the influence of the dead time to the static and dynamic losses of SiC-MOSFET and internal body diode a calculation of the possible output current versus frequency is performed. Finally the results are verified by calorimetrie measurements in a real inverter application.

Fully integrated high voltage high current gate driver for MOSFET-inverters

A new gate driver IC in SOI technology is presented which integrates all primary and secondary side driver functions for a three-phase MOSFET power inverter system and with brake chopper on a single chip. Thanks to the used SOI technology which blocks voltages in both directions an unique property of the IC is the potential separation for each secondary side thus allowing a decoupling from the primary side as known from solutions with galvanic isolation. For control and fault signal transmission advanced level shifter circuits are used. The IC furthermore includes short circuit protection (VDS-monitoring for each switch), operation voltage monitoring and advanced error management with detailed error read-out. The presented static and dynamic measurement results demonstrate the driver performance and the regular operation in the inverter system.

Fully integrated SOI gate driver for control of 1200V IGBT switches in three-level-NPC topology

A novel gate driver for the control of 1200V IGBT switches in Three-Level Neutral Point Clamp (3L-NPC) half bridges based on high voltage silicon on insulator (SOI) technology is presented. The driver features a safety concept dedicated for 3L-NPC applications. The three dies of this multichip solution are assembled in a tiny cost effective IC package with excellent electrical and thermal properties. The measurement results demonstrate the driver performance at high voltage switching and power inverter operation. The new driver approach supports the market needs for cost efficient 3L gate driver circuits.