el2166 Intersil Corporation, el2166 Datasheet - Page 13

• Manufacturer Part Number: el2166
• Description: 110mhz Current Feedback Amplifier With Disable
• Manufacturer: Intersil Corporation

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 I
quiescent supply current flowing in the output driver
transistor should be subtracted from the first term because,
under loading and due to the class AB nature of the output
stage, the output driver current is now included in the second
term.)
In general, an amplifier's AC performance degrades at
higher operating temperature and lower supply current.
Unlike some amplifiers, the EL2166 maintains almost
constant supply current over temperature so that AC
performance is not degraded as much over the entire
operating temperature range. Of course, this increase in
performance doesn't come for free. Since the current has
increased, supply voltages must be limited so that maximum
power ratings are not exceeded.
The EL2166 consumes typically 7.5mA and maximum
10.0mA. The worst case power in an IC occurs when the
output voltage is at half supply, if it can go that far, or its
maximum values if it cannot reach half supply. If we set the
two P
we can get a family of curves for various loads and output
voltages according to:
The following curves show supply voltage (±V
for various output voltage swings for the 2 different
DMAX
S
is the supply current. (To be more accurate, the
P
V
equations equal to each other, and solve for V
DMAX
S
=
R
-------------------------------------------------------------- -
--------------------------------------------------------------------------------------------- -
L
=
u
2
T
u
§
©
JMAX
V
2
S
T
u
JA
+
I
S
13
–
V
u
T
S
R
AMAX
L
–
·
¹
V
+
OUT
V
OUT
+
u
V
V
--------------- -
OUT
OUT
R
S
L
) vs R
2
LOAD
S
,
EL2166
packages. The curves assume worst case conditions of
T
The curves do not include heat removal or forcing air, or the
simple fact that the package will probably be attached to a
circuit board, which can also provide some form of heat
removal. Larger temperature and voltage ranges are
possible with heat removal and forcing air past the part.
Current Limit
The EL2166 has an internal current limit that protects the
circuit in the event of the output being shorted to ground.
This limit is set at 80mA nominally and reduces with junction
temperature. At a junction temperature of 150°C, the current
limits at about 50mA. If the output is shorted to ground, the
power dissipation could be well over 1W. Heat removal is
required in order for the EL2166 to survive an indefinite
short.
Driving Cables and Capacitive Loads
When used as a cable driver, double termination is always
recommended for reflection-free performance. For those
applications, the back termination series resistor will
decouple the EL2166 from the capacitive cable and allow
extensive capacitive drive. However, other applications may
have high capacitive loads without termination resistors. In
these applications, an additional small value (5:–50:)
resistor in series with the output will eliminate most peaking.
The gain resistor, R
loss created by this additional series resistor at the output.
A
= +85°C and I
S
Supply Voltage vs R
Various V
Supply Voltage vs R
Various V
= 10mA.
G
, can be chosen to make up for the gain
OUT
OUT
(SO Package)
(PDIP Package)
LOAD
LOAD
for
for