See igbt operation discussion and diagrams, Theory of operation, Insulated gate bipolar transistor (igbt) operation – Lincoln Electric INVERTEC SVM199-A User Manual
Page 39: A. passive b. active
THEORY OF OPERATION
E-7
E-7
INVERTEC® V450-PRO
INSULATED GATE BIPOLAR
TRANSISTOR (IGBT)
OPERATION
An IGBT is a type of transistor. IGBT are semiconduc-
tors well suited for high frequency switching and high
current applications.
Example A in Figure E.6 shows an IGBT in passive
mode. There is no gate signal, zero volts relative to the
source, and therefore, no current flow. The drain termi-
nal of the IGBT may be connected to a voltage supply;
but since there is no conduction, the circuit will not sup-
ply current to components connected to the source.
The circuit is turned OFF like a light switch.
FIGURE E.6 - IGBT OPERATION
Example B shows the IGBT in an active mode. When
the gate signals a positive DC voltage relative to the
source, is applied to the gate terminal of the IGBT, it is
capable of conducting current. A voltage supply con-
nected to the drain terminal will allow the IGBT to con-
duct and supply current to the circuit components cou-
pled to the source. Current will flow through the con-
ducting IGBT to downstream components as long as
the positive gate signal is present. This is similar to
turning ON a light switch.
DRAIN
SOURCE
GATE
A. PASSIVE
B. ACTIVE
BODY REGION
DRAIN DRIFT REGION
BUFFER LAYER
INJECTING LAYER
DRAIN
SOURCE
GATE
BODY REGION
DRAIN DRIFT REGION
BUFFER LAYER
INJECTING LAYER
n+
n+
P
n-
n+
P+
n+
n+
P
n-
n+
P+
POSITIVE
VOLTAGE
APPLIED
DRAIN
SOURCE
GATE
A. PASSIVE
B. ACTIVE
BODY REGION
DRAIN DRIFT REGION
BUFFER LAYER
INJECTING LAYER
DRAIN
SOURCE
GATE
BODY REGION
DRAIN DRIFT REGION
BUFFER LAYER
INJECTING LAYER
n+
n+
P
n-
n+
P+
n+
n+
P
n-
n+
P+
POSITIVE
VOLTAGE
APPLIED