el5244 Intersil Corporation, el5244 Datasheet - Page 17

• Manufacturer Part Number: el5244
• Description: 100mhz Single-supply Rail-to-rail Amplifiers
• Manufacturer: Intersil Corporation

relative to the GND pin. Letting the CE pin float will enable
the amplifier. Hence, the 8-pin PDIP and SOIC single amps
are pin compatible with standard amplifiers that don’t have a
power down feature.
Short Circuit Current Limit
The EL5144 series amplifiers do not have internal short
circuit protection circuitry. Short circuit current of 90mA
sourcing and 65mA sinking typically will flow if the output is
trying to drive high or low but is shorted to half way between
the rails. 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 ±50mA. This limit is set by internal
metal interconnect limitations. Obviously, short circuit
conditions must not remain or the internal metal connections
will be destroyed.
Power Dissipation
With the high output drive capability of the EL5144 series
amplifiers, 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 load conditions or package type need to be
modified for the amplifier to remain in the safe operating
area.
The maximum power dissipation allowed in a package is
determined according to:
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:
where:
PD
T
T
θ
PD
N = Number of amplifiers in the package
V
I
V
R
PD
SMAX
AMAX
JA
JMAX
OUT
S
L
MAX
MAX
MAX
= Load resistance tied to ground
= Total supply voltage
= Thermal resistance of the package
= Maximum output voltage of the application
=
= Maximum supply current per amplifier
= Maximum junction temperature
= Maximum ambient temperature
= Maximum power dissipation in the package
=
N
T
-------------------------------------------- -
×
JMAX
V
S
θ
×
JA
- T
I
SMAX
AMAX
+
(
17
V
S
- V
EL5144, EL5146, EL5244, EL5246, EL5444
OUT
)
×
V
--------------- -
OUT
R
L
If we set the two PD
can solve for R
Assuming worst case conditions of T
V
below is a table of all packages and the minimum R
allowed.
EL5144 Series Comparator Application
The EL5144 series amplifier can be used as a very fast,
single supply comparator. Most op amps used as a
comparator allow only slow speed operation because of
output saturation issues. The EL5144 series amplifier
doesn’t suffer from output saturation issues. Figure 3 shows
the amplifier implemented as a comparator. Figure 4 is a
OUT
R
L
EL5144CW
EL5146CN
EL5244CN
EL5246CN
EL5444CU
EL5444CN
EL5146CS
EL5244CS
EL5244CY
EL5246CY
EL5246CS
EL5444CS
=
= V
PART
--------------------------------------------------------------------------------------------- -



T
-------------------------------------------- -
S
JMAX
/2V, V
N
V
×
L
OUT
- T
:
θ
S
JA
AMAX
= 5.5V, and I
×
MAX
(
V
S



equations equal to each other, we
- V
- V
PACKAGE
MSOP-10
QSOP-16
SOT23-5
MSOP-8
SOIC-14
SOIC-14
PDIP-14
PDIP-14
(
SOIC-8
PDIP-8
SOIC-8
PDIP-8
OUT
S
×
SMAX
)
I
SMAX
A
= 8.8mA per amplifier,
= +85°C,
)
MINIMUM R
139
37
21
14
48
30
69
69
34
23
85
51
L
L