MMDF2C03HD ON Semiconductor, MMDF2C03HD Datasheet - Page 7

• Manufacturer Part Number: MMDF2C03HD
• Description: Power MOSFET
• Manufacturer: ON Semiconductor

are very important in systems using it as a freewheeling or
commutating diode. Of particular interest are the reverse
recovery characteristics which play a major role in
determining switching losses, radiated noise, EMI and RFI.
the body diode itself. The body diode is a minority carrier
device, therefore it has a finite reverse recovery time, t
to the storage of minority carrier charge, Q
the typical reverse recovery wave form of Figure 15. It is this
stored charge that, when cleared from the diode, passes
through a potential and defines an energy loss. Obviously,
repeatedly forcing the diode through reverse recovery
further increases switching losses. Therefore, one would
like a diode with short t
minimize these losses.
amount of radiated noise, voltage spikes, and current
ringing. The mechanisms at work are finite irremovable
circuit parasitic inductances and capacitances acted upon by
The switching characteristics of a MOSFET body diode
System switching losses are largely due to the nature of
The abruptness of diode reverse recovery effects the
3.0
2.5
2.0
1.5
1.0
0.5
0
0.5
Figure 10. Diode Forward Voltage versus Current
T
V
J
GS
= 25°C
0.55
= 0 V
V
SD
, SOURCE−TO−DRAIN VOLTAGE (VOLTS)
0.6
rr
N−Channel
0.65
and low Q
DRAIN−TO−SOURCE DIODE CHARACTERISTICS
0.7
RR
0.75
specifications to
RR
, as shown in
0.8
http://onsemi.com
MMDF2C03HD
rr
, due
0.85
7
high di/dts. The diode’s negative di/dt during t
controlled by the device clearing the stored charge.
However, the positive di/dt during t
diode characteristic and is usually the culprit that induces
current ringing. Therefore, when comparing diodes, the
ratio of t
abruptness and thus gives a comparative estimate of
probable noise generated. A ratio of 1 is considered ideal and
values less than 0.5 are considered snappy.
low voltage MOSFETs, high cell density MOSFET diodes
are faster (shorter t
reverse recovery characteristic. The softness advantage of
the high cell density diode means they can be forced through
reverse recovery at a higher di/dt than a standard cell
MOSFET diode without increasing the current ringing or the
noise generated. In addition, power dissipation incurred
from switching the diode will be less due to the shorter
recovery time and lower switching losses.
1.6
1.2
0.8
0.4
Compared to ON Semiconductor standard cell density
2
0
0.5
Figure 10. Diode Forward Voltage versus Current
T
V
J
GS
= 25°C
0.7
b
= 0 V
/t
V
a
SD
serves as a good indicator of recovery
, SOURCE−TO−DRAIN VOLTAGE (VOLTS)
0.9
rr
), have less stored charge and a softer
1.1
P−Channel
1.3
b
is an uncontrollable
1.5
a
1.7
is directly
1.9