11
Application Information
On-Resistance and Derating Curves
The Output On-Resistance, R
(ON),
specied in this data
sheet, is the resistance measured across the output con-
tact when a pulse current signal (lo=200mA) is applied
to the output pins. The use of a pulsed signal (≤30ms)
implies that each junction temperature is equal to the
ambient and case temperatures. The steady-state resis-
tance, Rss, on the other hand, is the value of resistance
measured across the output contact when a DC current
signal is applied to the output pins for a duration suf-
cient to reach thermal equilibrium. Rss includes the ef-
fects of the temperature rise in the device.
Figure 1, 2, 3 and 4 specify the maximum average out-
put current allowable for a given ambient temperature.
The maximum allowable output current and power dis-
sipation are related by the expression Rss = Po(max)/
(lo(max))
2
from which Rss can be calculated. Staying
within the safe area assures that the steady state MOS-
FET junction temperature remains less than 125 °C.
T
A
- TEMPERATURE - ˚C
I
O
- OUTPUT CURRENT - A
T
A
- TEMPERATURE - ˚C
I
O
- OUTPUT CURRENT - A I
O
- OUTPUT CURRENT - A
I
O
- OUTPUT CURRENT - A
T
A
- TEMPERATURE - ˚C T
A
- TEMPERATURE - ˚C
0
0.05
0.1
0.15
0.2
0
0.05
0.1
0.15
0.2
0
0.05
0.1
0.15
0.2
-40 -20 0 20 40 60 80 100
-40 -20 0 20 40 60 80 100 -40 -20 0 20 40 60 80 100
-40 -20 0 20 40 60 80 100
Safe
Operating
Area
I
F
= 10mA, 4-Layer Board I
F
= 10mA, 4-Layer Board
I
F
= 10mA, 4-Layer Board I
F
= 10mA, 4-Layer Board
Safe
Operating
Area
1-Channel & 2-Channel
Safe
Operating
Area
0
0.1
0.2
0.3
0.4
0.5
Safe
Operating
Area
Figure 1. Maximum Output Current Rating vs Ambient Temperature
(ASSR-1218-003E)
Figure 2. Maximum Output Current Rating vs Ambient Temperature
(ASSR-1219-001E)
Figure 3. Maximum Output Current Rating vs Ambient Temperature
(ASSR-1219-001E DC Connection)
Figure 4. Maximum Output Current Rating vs Ambient Temperature
(ASSR-1228-002E)