MTD20N06HDL ON Semiconductor, MTD20N06HDL Datasheet - Page 5

• Manufacturer Part Number: MTD20N06HDL
• Description: Power Mosfet 20 Amps, 60 Volts, Logic Level
• 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 10. 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
12
10
8
6
4
2
0
Figure 8. Gate−To−Source and Drain−To−Source
0
Q1
2
Voltage versus Total Charge
Q3
4
Q
V
G
DS
, TOTAL GATE CHARGE (nC)
6
rr
QT
and low Q
Q2
8
DRAIN−TO−SOURCE DIODE CHARACTERISTICS
20
16
12
8
4
0
10
0.5
Figure 10. Diode Forward Voltage versus Current
RR
V
T
GS
J
specifications to
= 25°C
12
RR
0.55
V
= 0 V
GS
, as shown in
I
T
V
D
J
SD
= 20 A
= 25°C
14
0.6
, SOURCE−TO−DRAIN VOLTAGE (Volts)
http://onsemi.com
rr
, due
16
0.65
60
50
40
30
20
10
0
5
0.7
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.
1000
Compared to ON Semiconductor standard cell density
100
10
0.75
1
1
V
I
V
T
D
J
DD
GS
= 20 A
= 25°C
b
0.8
/t
= 30 V
= 5 V
Figure 9. Resistive Switching Time
a
Variation versus Gate Resistance
serves as a good indicator of recovery
0.9
t
t
d(on)
d(off)
rr
R
G
), have less stored charge and a softer
t
t
r
f
, GATE RESISTANCE (Ohms)
0.95
10
b
is an uncontrollable
a
is directly
100