High Frequency MOSFET Gate Drivers: Technologies and Applications
This book describes high frequency power MOSFET gate driver technologies, including gate drivers for GaN HEMTs, which have great potential in the next generation of switching power converters. Gate drivers serve as a critical role between control and power devices. In recent years, there has been a trend to increase the switching frequency beyond multi-MHz in switching power converters to reduce the passive components and significantly improve power density. However, this results in high switching loss and gate driver loss in power MOSFETs. The novel approach in this book is the proposed Current Source Gate Driver (CSD) including different topologies, control and applications. The CSD can reduce the switching transition time and switching loss significantly, and recover high frequency gate driver loss compared to conventional voltage gate drivers. The basic idea can also be extended to other power devices to improve high frequency switching performance such as SiC MOSFET and IGBT. Topics covered in the book include the state-of-the-art of power MOSFET drive techniques, the switching loss model, current source gate drivers (CSDs), resonant gate drivers, adaptive gate drivers and GaN HEMT gate drivers. The book is essential reading for design engineers, researchers and advanced students working in switching power supplies and in power electronics generally.
Inspec keywords: insulated gate bipolar transistors; HEMT circuits; constant current sources; gallium compounds; power MOSFET; silicon compounds; driver circuits; switching convertors
Other keywords: switching-transition time; switching power supplies; power devices; IGBT; high-frequency power MOSFET gate driver technologies; adaptive gate drivers; switching-loss model; resonant gate drivers; power electronics field; power density; state-of-the-art power MOSFET drive technique; voltage gate drivers; multiMHz; high-switching loss; current source gate drivers; passive components; GaN; next generation switching-power converters; switching frequency; SiC MOSFET; gate-driver loss; SiC; GaN HEMT gate drivers; CSDs
Subjects: Power electronics, supply and supervisory circuits; Power semiconductor devices; Insulated gate field effect transistors
- Book DOI: 10.1049/PBCS033E
- Chapter DOI: 10.1049/PBCS033E
- ISBN: 9781785613654
- e-ISBN: 9781785613661
- Page count: 300
- Format: PDF
-
Front Matter
- + Show details - Hide details
-
p.
(1)
-
1 Introduction
- + Show details - Hide details
-
p.
1
–12
(12)
Power MOSFETs are popular in numerous high-frequency power converters applications extensively. With the high-frequency trend of power converters, the high-frequency switching loss and gate drive loss need to be minimized, which causes serious challenge on advanced high-speed gate driver technology since the gate drivers serve as a critical role between the control and power devices. This book focuses on the gate driver topic systematically providing the fundamental knowledge of high-frequency gate driver technologies.
-
2 Fundamentals of current source driver
- + Show details - Hide details
-
p.
13
–43
(31)
Resonant gate drivers were originally developed to recover part of MOSFET gatedrive loss when operating at high switching frequency. Most of investigations are generally emphasizing gate energy savings by the resonant driver and concentrating on the drive topologies, but ignore the potential switching loss savings that are much more dominant in MHz switching power converter. The idea of the CSDs is to build strong gate-drive current during the switching transition to realize quick turn-on and turn-off transition and reduce high-frequency switching loss and gate-drive loss in power MOSFETs. The switching loss characteristics and behavior in a high-frequency synchronous buck VR is investigated and the parasitic inductances act as a current snubber at turn on to reduce turn-on loss, but prolong the turn-off time and increase turn-off loss.
-
3 Continuous current source driver
- + Show details - Hide details
-
p.
45
–101
(57)
This chapter presents a two-channel current source driver (CSD) with the continuous current, which can provide two symmetrical drive signals for driving two metal oxide semiconductor field-effect transistors (MOSFETs). The proposed drive circuit can recover most of the driving energy. It can also reduce the switching loss significantly. The proposed CSD can be used to drive the synchronous rectifier (SR) in a current doubler or full-wave rectifier. It can also be used to drive the primary MOSFETs in push-pull converters.
-
4 Discontinuous current source drivers
- + Show details - Hide details
-
p.
103
–158
(56)
This chapter presents different discontinuous current source drivers (CSDs) for the power metal oxide semiconductor field-effect transistors (MOSFETs). These drivers aim to reduce switching loss by providing a near constant gate charging and discharging currents to switch quickly. Furthermore, they can recover a portion of the QV gate energy otherwise lost in conventional voltage source drivers (VSDs).
-
5 Adaptive current source drivers
- + Show details - Hide details
-
p.
159
–187
(29)
Compared to the previous CSDs, the adaptive-drive current and drive voltage can be realized to optimize the switching loss reduction and the drive loss reduction at different load currents. It should be noted that the adaptive concept is suitable for both the continuous and discontinuous CSDs regardless of the drive-circuit topologies. The linear regulator can be used to achieve the function of the adaptive voltage and drive current in a cost-effective manner.
-
6 Resonant gate drivers
- + Show details - Hide details
-
p.
189
–230
(42)
The forward recovery of the diodes causes poor performance and high conduction loss in the multi-MHz resonant converters. A simple and efficient self-driven RGD is presented. A control stage comprised of a shutdown branch and an auxiliary switch is introduced to the RGD to block the circulating current and the lowimpedance path in the drive circuit, so that the gate voltage can achieve fast shutdown and buildup under ON-OFF operation to ensure fast transient response. Moreover, the proposed RGD generates a tunable d.c. bias to increase the peak gate voltage and extend the conduction time with the optimal RDS(on), so that the average RDS(on) and the associated conduction loss in the SR FET can be reduced. It also provides precise switching timing for the SR to minimize the body diode conduction loss. An isolated RGD for two MOSFETs in one bridge-leg is presented. The proposed RGD can provide two complementary drive signals to drive two MOSFETs, which can be used to drive the HB leg in FB converters. Moreover, with the negative drive voltage capability, the proposed RGD ensures high reliability in the FB converters over the previously proposed RGDs.
-
7 eGaN HEMTs gate drivers
- + Show details - Hide details
-
p.
231
–272
(42)
A three-level driving circuit is proposed for eGaN control HEMTs with multi-MHz. The mid-level voltage reduces the reverse conduction loss before ZVS turn-on interval by reducing the reverse conduction voltage since that the source-to-drain voltage decreases when the gate voltage increases. The driving circuit layout and driving resistance selection are investigated to quantitatively analyze the negative gate bias requirement to prevent the false turn-on. The proposed driving circuit can reduce the high reverse conduction loss using the constructed positive gate bias, while achieve desired dv/dt immunity. The proposed driving circuit is applied to a 7 MHz isolated resonant SEPIC converter. With 24 V input and 5 V/10 W output, the driving circuit improves the efficiency of 0.7% (from 72.7% without the mid-level voltage to 73.4% with the mid-level voltage) over the conventional driving circuit.
-
Back Matter
- + Show details - Hide details
-
p.
(1)