el2082 Intersil Corporation, el2082 Datasheet - Page 10

• Manufacturer Part Number: el2082
• Description: Current Mode Multiplier
• Manufacturer: Intersil Corporation

Reactive Couplings with the EL2082
The above sketch is an excerpt of a receiver IF amplifier
showing methods of connecting the EL2082 to reactive
networks. The I
100MHz, and the output looks like a simple current-source in
parallel with about 5pF. There is no particular problem with
any resistance or reactance connected to I
mixer output is generally sent to a crystal filter, which
required a few hundred ohm terminating impedance. The
impedance of the I
about 400 by the 2:1 transformer T1. The two EL2082s are
used as variable-gain IF amplifiers, with small gains offered
by each. The output of the first EL2082 is coupled to the
second by the resonant matching network L1-C1. For a Q of
5, Xc1 = x11 = 5 x 95 , approximately. The impedance seen
at the first EL2082's I
and by impedance transformation alone the first gain cell
delivers 28dB of gain at V
used for a wider range of (calibrated) AGC compliance.
The E input can be used as a high-speed noise blanker gate.
IN
pin of the EL2082 looks like 95
IN
pin of the first EL2082 is transformed to
OUT
G
will be about Q
= 1V. More gain cells can be
10
Dual EL2082 Fader with EL2030
NTSC Differential Gain Error
FIGURE 7. EXAMPLE REACTIVE COUPLINGS WITH EL2082’S
2
IN
x 95 , or 2.5k,
or I
OUT
well past
. The
EL2082
Linearized Fader/Gain Control
The following circuit is an example of placing two EL2082s in
the feedback network of an op-amp to significantly reduce
their distortions:
FIGURE 8. LINEARIZED GAIN CONTROL/FADER
Dual EL2082 Fader with EL2030
NTSC Differential Phase Error
V
where 0
OUT
= K • V
K
A
1
+ (1-K) • V
B