Datasheet

AD8236
Rev. 0 | Page 7 of 20
ABSOLUTE MAXIMUM RATINGS
Table 4.
Parameter Rating
Supply Voltage 6 V
Power Dissipation See Figure 3
Output Short-Circuit Current 55 mA
Input Voltage (Common Mode) ±V
S
Differential Input Voltage ±V
S
Storage Temperature Range −65°C to +125°C
Operating Temperature Range −40°C to +125°C
Lead Temperature (Soldering, 10 sec) 300°C
Junction Temperature 140°C
θ
JA
(4-Layer JEDEC Standard Board)
8-Lead MSOP 135°C/W
Package Glass Transition Temperature
8-Lead MSOP 140°C
ESD
Human Body Model 2 kV
Charge Device Model 1 kV
Machine Model 200 V
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
MAXIMUM POWER DISSIPATION
The maximum safe power dissipation in the package of the
AD8236 is limited by the associated rise in junction temperature
(T
J
) on the die. The plastic encapsulating the die locally reaches
the junction temperature. At approximately 140°C, which is the
glass transition temperature, the plastic changes its properties.
Even temporarily exceeding this temperature limit may change
the stresses that the package exerts on the die, permanently
shifting the parametric performance of the AD8236.
The still-air thermal properties of the package and PCB (θ
JA
),
the ambient temperature (T
A
), and the total power dissipated in
the package (P
D
) determine the junction temperature of the die.
The junction temperature is calculated as
T
J
= T
A
+ (P
D
× θ
JA
)
The power dissipated in the package (P
D
) is the sum of the
quiescent power dissipation and the power dissipated in the
package due to the load drive for all outputs. The quiescent
power is the voltage between the supply pins (V
S
) times the
quiescent current (I
S
). Assuming the load (R
L
) is referenced to
midsupply, the total drive power is V
S
/2 × I
OUT
, some of which
is dissipated in the package and some in the load (V
OUT
× I
OUT
).
The difference between the total drive power and the load power is
the drive power dissipated in the package.
P
D
= Quiescent Power + (Total Drive Power – Load Power)
()
L
OUT
L
OUTS
SS
D
R
V
R
V
V
IVP
2
–
2
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
×+×=
RMS output voltages should be considered. If R
L
is referenced to
−V
S
, as in single-supply operation, the total drive power is V
S
×
I
OUT
. If the rms signal levels are indeterminate, consider the worst
case, when V
OUT
= V
S
/4 for R
L
to midsupply
()
(
)
L
S
SS
D
R
/V
IVP
2
4
+×=
In single-supply operation with R
L
referenced to −V
S
, worst case
is V
OUT
= V
S
/2.
Airflow increases heat dissipation, effectively reducing θ
JA
. In
addition, more metal directly in contact with the package leads
from metal traces, through holes, ground, and power planes
reduces the θ
JA
.
Figure 3 shows the maximum safe power dissipation in the package
vs. the ambient temperature for the 8-lead MSOP on a 4-layer
JEDEC standard board. θ
JA
values are approximations.
2.00
0
–40 120
AMBIENT TEMPERATURE (°C)
MAXIMUM POWER DISSIPATION (W)
1.75
1.50
1.25
1.00
0.75
0.50
0.25
–20 0 20 40 60 80 100
08000-045
Figure 3. Maximum Power Dissipation vs. Ambient Temperature
ESD CAUTION