MOSFET with Limited di/dt
Purpose
Dynamic MOSFET model with finite current slopes during turn-on and
turn-off
Library
Electrical / Power Semiconductors
Description
In contrast to the ideal MOSFET model that switches instantaneously, this model
includes drain current transients during switching. Thanks to the continuous current
decay during turn-off, stray inductances may be connected in series with the
device.
This MOSFET model is used to simulate overvoltages produced by parasitic
inductances and the reverse recovery effect of diodes. Due to simplified voltage and
current transient waveforms, the model is not suited for the simulation of switching
losses. The dynamic behavior of this MOSFET model is identical with the one of the
IGBT with limited di/dt.
Note
- Due to the small time-constants introduced by the turn-on and turn-off
transients a stiff solver is recommended for this device model.
- If multiple MOSFETs are connected in series, the off-resistance may not
be infinite.
Parameters
-
Blocking voltage
- Maximum voltage
in volts (V) that under any conditions
should be applied between drain and source.
-
Continuous drain current
- Maximum dc current
in ampere (A) that the
MOSFET can conduct.
-
On-resistance
- The resistance
of the conducting device, in ohms (
). The
default is 0.
-
Off-resistance
- The resistance
of the blocking device, in ohms (
). The
default is inf. If multiple IGBTs are connected in series, the off-resistance must
have a large finite value.
-
Rise time
- Time
in seconds between instants when the drain current has risen
from 10 % to 90 % of the continuous drain current
.
-
Fall time
- Time
in seconds between instants when the drain current has
dropped from 90 % to 10 % of its initial value along an extrapolated straight
line tangent the maximum rate-of-change of the current.
-
Fall time
- Time
in seconds between instants when the drain current has
dropped from 90 % to 10 % of its initial value along an extrapolated straight
line tangent the maximum rate-of-change of the current decay.
-
Stray inductance
- Internal inductance
in henries (H) measured between the
drain and source terminals.
-
Initial current
- The initial current through the component at simulation start, in
amperes (A). The default is 0.
Probe Signals
-
MOSFET voltage
- The voltage measured between drain and source.
-
MOSFET current
- The current through the MOSFET flowing from drain to
source.
-
MOSFET conductivity
- Conduction state of the internal switch. The signal
outputs 0 when the MOSFET is blocking, and 1 when it is conducting.