11
Applications Information
On-Resistance and Derating Curves
The Output On-Resistance, R
(ON)
, speci ed in this data
sheet, is the resistance measured across the output
contact when a pulsed current signal (Io = 120 mA) is
applied to the output pins. The use of a pulsed signal
(≤ 30 ms) implies that each junction temperature is
equal to the ambient and case temperatures. The
steady-state resistance, Rss, on the other hand, is the
value of the resistance measured across the output
contact when a DC current signal is applied to the
output pins for a duration su cient to reach thermal
equilibrium. Rss includes the e ects of the temperature
rise in the device.
Figure 2. Maximum Output Current Rating vs Ambient Temperature
(ASSR-4111-001E)
Figure 1. Maximum Output Current Rating vs Ambient Temperature
(ASSR-4110-003E)
Figure 1, 2, 3 and 4 specify the maximum average
output current allowable for a given ambient tem-
perature. The maximum allowable output current and
power dissipation are related by the expression Rss =
Po(max)/(Io(max))
2
from which Rss can be calculated.
Staying within the safe area assures that the steady
state MOSFET junction temperature remains less than
125°C.
Turn On Time and Turn O Time Variation
The ASSR-41xx Series exhibits a very fast turn on and
turn o time. Both the turn on and turn o time can
be adjusted by choosing proper forward current as
depicted in Figures 11 and 13. The changes of the turn
on and turn o time with ambient temperature are also
shown in Figures 12 and 14.
Figure 4. Maximum Output Current Rating vs Ambient Temperature,
ASSR-4120-002E
Figure 3. Maximum Output Current Rating vs Ambient Temperature
(ASSR-4111-001E) DC Connection
I
O
- OUTPUT CURRENT - A
0
0.04
0.08
0.12
-40 -20 0 20 40 60 80 100
T
A
- TEMPERATURE - °C
I
F
= 10mA, 4-Layer Board
Safe
Operating
Area
0
0.04
0.08
0.12
-40 -20 0 20 40 60 80 100
I
F
= 10mA, 4-Layer Board
Safe
Operating
Area
T
A
- TEMPERATURE - °C
I
O
- OUTPUT CURRENT - A
0
0.04
0.08
0.12
0.16
0.20
0.24
-40 -20 0 20 40 60 80 100
Safe
Operating
Area
I
F
= 10mA, 4-Layer Board
T
A
- TEMPERATURE - °C
I
O
- OUTPUT CURRENT - A
0
0.04
0.08
0.12
-40 -20 0 20 40 60 80 100
I
F
= 10mA, 4-Layer Board
1-Channel
2-Channel
Safe
Operating
Area
T
A
- TEMPERATURE - °C
I
O
- OUTPUT CURRENT - A