
Data Sheet
ADA4937-1/ADA4937-2
Rev. D | Page 7 of 28
ABSOLUTE MAXIMUM RATINGS
Table 5.
Parameter
Rating
Supply Voltage
5.5 V
Power Dissipation
Storage Temperature Range
65°C to +125°C
Operating Temperature Range
40°C to +105°C
Lead Temperature (Soldering, 10 sec)
300°C
Junction Temperature
150°C
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.
THERMAL RESISTANCE
θJA is specified for the device (including exposed pad) soldered
to a high thermal conductivity 2s2p circuit board, as described
in EIA/JESD51-7.
Table 6. Thermal Resistance
Package Type
θJA
Unit
16-Lead LFCSP (Exposed Pad)
95
°C/W
24-Lead LFCSP (Exposed Pad)
67
°C/W
Maximum Power Dissipation
The maximum safe power dissipation in th
e ADA4937-x packages
is limited by the associated rise in junction temperature (TJ) on
the die. At approximately 150°C, which is the glass transition
temperature, the plastic changes its properties. Even temporarily
exceeding this temperature limit can change the stresses that the
package exerts on the die, permanently shifting the parametric
temperature of 150°C for an extended period can result in
changes in the silicon devices, potentially causing failure.
The power dissipated in the package (PD) is the sum of the
quiescent power dissipation and the power dissipated in the
package due to the load drive. The quiescent power is the voltage
between the supply pins (VS) times the quiescent current (IS).
The power dissipated due to the load drive depends upon the
particular application. The power due to load drive is calculated
by multiplying the load current by the associated voltage drop
across the device. RMS voltages and currents must be used in
these calculations.
Airflow increases heat dissipation, effectively reducing θJA. In
addition, more metal directly in contact with the package
leads/exposed pad from metal traces, through holes, ground,
and power planes reduces θJA.
Figure 4 shows the maximum safe power dissipation in the
package vs. the ambient temperature for the
ADA4937-1 single
LFCSP (67°C/W) on a JEDEC standard 4-layer board.
3.5
0
–40
110
90 100
MA
XI
MU
M
PO
W
ER
D
ISSI
PA
T
IO
N
(W
)
AMBIENT TEMPERATURE (°C)
06591-
004
0.5
1.0
1.5
2.0
2.5
3.0
–30 –20 –10 0
10 20 30 40 50 60 70 80
ADA4937-2
ADA4937-1
Figure 4. Maximum Power Dissipation vs. Temperature, 4-Layer Board
ESD CAUTION