el2250 Intersil Corporation, el2250 Datasheet - Page 12

• Manufacturer Part Number: el2250
• Description: 125mhz Single Supply Dual/quad Op Amps
• Manufacturer: Intersil Corporation

Short Circuit Current Limit
The EL2250/EL2450 have internal short circuit protection
circuitry that protect it in the event of its output being shorted
to either supply rail. This limit is set to around 100mA
nominally and reduces with increasing junction temperature.
It is intended to handle temporary shorts. If an output is
shorted indefinitely, the power dissipation could easily
increase such that the part will be destroyed. Maximum
reliability is maintained if the output current never exceeds
±90mA. A heat sink may be required to keep the junction
temperature below absolute maximum when an output is
shorted indefinitely.
Power Dissipation
With the high output drive capability of the EL2250/EL2450,
it is possible to exceed the 150°C Absolute Maximum
junction temperature under certain load current conditions.
Therefore, it is important to calculate the maximum junction
temperature for the application to determine if power-supply
voltages, load conditions, or package type need to be
modified for the EL2250/EL2450 to remain in the safe
operating area.
FIGURE 2.
12
EL2250, EL2450
The maximum power dissipation allowed in a package is
determined according to [1]:
where:
The maximum power dissipation actually produced by an IC
is the total quiescent supply current times the total power
supply voltage, plus the power in the IC due to the load, or
[2]:
where:
If we set the two PD
other, and solve for V
various loads and output voltages according to [3]:
Figures 3 through 6 below show total single supply voltage
V
SO packages. The curves assume WORST CASE
conditions of T
S
T
T
T
PD
N = Number of amplifiers
V
I
V
R
SMAX
JA
vs. R
JMAX
AMAX
S
OUT
L
MAX
= Load Resistance tied to Ground
= Total Supply Voltage
PD
= Thermal Resistance of the Package
V
L
= Maximum Output Voltage of the Application
MAX
= Maximum Supply Current per amplifier
= Maximum Junction Temperature
S
= Maximum Ambient Temperature
for various output voltage swings for the PDIP and
= Maximum Power Dissipation in the Package.
=
=
R
-------------------------------------------------------------- -
------------------------------------------------------------------------------------------ -
A
PD
L
N
= +85°C and I
u
u
MAX
T
§
¨
©
MAX
V
JMAX
S
N
s
IS
, we can get a family of curves for
u
u
=
u
T
I
equations, [1] & [2], equal to each
SMAX
T
-------------------------------------------- -
JA
–
R
JMAX
T
L
AMAX
+
S
+
V
T
= 6.5mA per amplifier.
–
JA
OUT
V
T
S
AMAX
+
–
V
V
OUT
OUT
u
V
--------------- -
OUT
R
L
June 7, 2005
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FN7061.2