Tobias Georg Tolle

A detailed analysis of a resonant gate driver for PWM applications

Gate drivers generate significant losses, especially at high frequencies. While conventional solutions dissipate all the energy, resonant gate drivers partly recover it. A resonant gate driver is studied in detail with the emphasis on PWM operation. Compared to other resonant drivers, the investigated driver combines simplicity, fast switching and loss reduction. Advantages and limits are discussed using a mathematical model and a prototype.

Switching loss contributions of synchronous rectifiers in VRM applications

For the synchronous buck converter used in VRM applications, one major contributor to switching losses is reverse recovery. These losses however cannot directly be measured because capacitive current and several other phenomena superimpose the mere reverse recovery. The paper describes how to calculate the capacitive part of the drain current and how to de-embed the channel current out of the total drain current. This can show the size of Q/sub rr/ and reveal effects such as gate bouncing and avalanche breakdown.

De-embedding of reverse recovery losses in fast switching VRM applications

For the synchronous buck converter used in VRM applications, one major contributor to switching losses is reverse recovery. These losses however cannot directly be measured because capacitive current and several other phenomena superimpose the mere reverse recovery. The paper describes how calculate the capacitive part of the drain current and how to de-embed the channel current out of the total drain current. This can show the size of Q/sub rr/ and reveal effects such as gate bouncing and avalanche breakdown.

PCS layout inductance modeling based on a time domain measurement approach

This paper presents a time domain measurement method to estimate the parasitic inductance of a Printed Circuit Board (PCB) layout. It is based on a lumped element model. The proposed measurement technique is also used for measuring the Equivalent Series Inductance (ESL) of devices such as low ohmic MOSFETs and high current shunt resistors. The PCB layout of a half bridge circuit is characterised as an application example.