POWER SEMICONDUCTOR SYSTEMS I

Author: Ales Havel

E-mail: ales.havel@vsb.cz

Phone number: 4287

Headquarters: E227

Web page: http://homen.vsb.cz/~hav278/

Presentation contents

Power semiconductor devices Power diode Thyristors

GTO thyristor IGCT thyristor MCT

Power transistors Bipolar transistor (BJT) MOSFET IGBT

Main types of converters

Power diode

Single P-N junction creates a diode that has two terminals: an anode (A) and a cathode (K).

Diode structure and symbol

Power diode

Steady State V-I Characteristic of a Diode

Power diode

Dynamic parameters Dynamic parameters relate to fast

transition from ON to OFF states Not only speed of transition between the

two states is important, but also changes in the diode voltage and current during the transition should be taken into account.

Power diode

Transient V-I Characteristic of a Diode

Power diode

Main requirements: reverse voltage Ur as high as possible voltage drop UF as low as possible turn-off speed as high as possible Qrr (reverse recovery charge) as low as

possible

Thyristor

Thyristor (SCR – Semiconductor Controlled Rectifier) is a controlled semiconductor device of 4-layer PNPN structure with 3 PN junctions.

Thyristor schematic symbol and structure

Thyristor

Steady-State V-I Characteristic of a Thyristor

Thyristor

Transient V-I Characteristics of a Thyristor

Thyristor

Switching conditions: To turn-on:

UA = UD > 0 (forward blocking state) Bring sufficiently high current IG into the gate

To turn-off: The forward current has to stop flowing A control electrode cannot effect thyristor turn-

off The IL current (latching current – min. value

to turn on) The IH current (holding current – min. value

to stay open)

GTO thyristor

GTO Thyristor schematic symbol and structure

GTO thyristor (Gate Turn-Off thyristor) is a semiconductor device built on the same principle as traditional thyristor. The difference is in the case that the GTO could be turned of by the negative gate current.

MCT thyristor

MOS Controlled Thyristor (MCT) is voltage controlled fully controllable thyristor.

The MCT is similar in operation with GTO thyristor, but it has voltage controlled insulated gate.

It has two MOSFETs in its equivalent circuit. One is responsible for turn-on and the another is responsible for turn-off.

Transistors

BJT transistor

A Bipolar (Junction) Transistor (BJT) is a three-terminal electronic device constructed of doped semiconductor material and may be used in amplifying or switching applications. Bipolar transistors are so named because their operation involves both electrons and holes.

The BJT has three terminals, corresponding to the three layers of semiconductor – an emitter, a base, and a collector.

Schematic mark

BJT transistor

Main principle of the BJT transistor

BaseCollector

Emitter Switching the BJT transistor

BJT transistor

Static characteristicsOutputTransfer

Input Reverse

MOSFET transistor

A Power MOSFET is a specific type of metal oxide semiconductor field-effect transistor that has been designed to handle large amounts of power.

N-Channel P-ChannelD

eple

tion

mod

eE

nh

ance

men

t m

ode

MOSFET transistor

Switching MOSFET

MOSFET transistor

Static characteristic MOSFET

Lineararea Saturation area

IGBT transistor

The Insulated Gate Bipolar Transistor (IGBT) is a minority-carrier device with high input impedance and large bipolar current-carrying capability.

Symbol and equivalent circuit model of an IGBT

IGBT tranzistor

Switching IGBT

IGBT tranzistor

Absolute maximum ratings

IGBT tranzistor

Electrical characteristic

IGBT

Thermal characteristic

IGBT

The IGBT is suitable for many applications in power electronics, especially in Pulse Width Modulated (PWM) servo and three-phase drives requiring high dynamic range control and low noise.

It also can be used in Uninterruptible Power Supplies (UPS), Switched-Mode Power Supplies (SMPS), and other power circuits requiring high switching repetition rates.

IGBT improves dynamic performance and efficiency and reduced the level of audible noise. It is equally suitable in resonant-mode converter circuits.

Optimized IGBT is available for both low conduction losses and low switching losses.

Comparison of power semiconductor devices

Power converters A power semiconductor converter is an

electrical device for converting electrical energy.

Thank You for your attention