AD834JR-REEL Analog Devices Inc, AD834JR-REEL Datasheet - Page 13

• Manufacturer Part Number: AD834JR-REEL
• Description: IC MULTIPLIER 4-QUADRANT 8-SOIC
• Manufacturer: Analog Devices Inc

Specifications of AD834JR-REEL

• Rohs Status: RoHS non-compliant
• Function: Analog Multiplier
• Number Of Bits/stages: 4-Quadrant
• Package / Case: 8-SOIC (3.9mm Width)
• Number Of Elements: 1
• Output Type: Differential
• Power Supply Requirement: Dual
• Single Supply Voltage (typ): Not RequiredV
• Single Supply Voltage (min): Not RequiredV
• Single Supply Voltage (max): Not RequiredV
• Dual Supply Voltage (typ): ±5V
• Dual Supply Voltage (min): ±4V
• Dual Supply Voltage (max): ±9V
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: SOIC
• Lead Free Status / RoHS Status: Not Compliant

the load should now be equal to the characteristic impedance of
the line (although this is usually not critical for short line lengths).
The collector load resistors, R
terminate the line, but again this is only necessary when an
electrically long line is used. In most cases, R
as the dc conditions allow to minimize power loss to the load.
The line can be a miniature coaxial cable or a twisted pair.
Note that the upper bandwidth limit of the balun is determined
only by the quality of the transmission line; therefore, the upper
bandwidth of the balun usually exceeds that of the multiplier.
This is unlike a conventional transformer where the signal is
conveyed as a flux in a magnetic core and is limited by core
losses and leakage inductance. The lower limit on bandwidth is
determined by the series inductance of the line, taken as a
whole, and the load resistance (if the blocking capacitors, C, are
sufficiently large). In practice, a balun can provide excellent
differential-to-single-sided conversion over much wider
bandwidths than a transformer.
WIDEBAND MULTIPLIER CONNECTIONS
When operation down to dc and a ground based output are
necessary, the configuration shown in Figure 18 can be used.
The element values were chosen in this example to result in a
full-scale output of ±1 V at the load, so the overall multiplier
transfer function is
where the X1, X2, Y1, Y2 inputs and W output are in volts. The
polarity of the output can be reversed simply by reversing either
the X or Y input.
X-INPUT
Y-INPUT
±1V FS
±1V FS
W = (X1 − X2)(Y1 − Y2)
TERMINATION
RESISTOR
TERMINATION
RESISTOR
Figure 17. Using a Balun at the Output
X2
Y1
8
1
1.5R
AD834
Y2 –V
X1 +V
4.7Ω
7
2
W
6
3
CERAMIC
S
S
CERAMIC
W
, can also be chosen to reverse-
W2
W1
1µF
1µF
5
4
R
W
R
W
C
C
W
is made as large
BALUN
TEXT
SEE
OUTPU
R
+5V
–5V
L
T
Rev. E | Page 13 of 20
Choose the op amp to support the desired output bandwidth.
The op amp originally used in Figure 18 was the AD5539,
providing an overall system bandwidth of 100 MHz. The
AD8009 should provide similar performance. Many other
choices are possible where lower post multiplication band-
widths are acceptable. The level shifting network places the
input nodes of the op amp to within a few hundred millivolts of
ground using the recommended balanced supplies. The output
offset can be nulled by including a 100 Ω trim pot between each
of the lower pair of resistors (3.74 kΩ) and the negative supply.
The pulse response for this circuit is shown in Figure 19; the
X input is a pulse of 0 V to 1 V and the Y input is 1 V dc. The
transition times at the output are about 4 ns.
±1V
±1V
X
Y
100
0%
90
10
49.9Ω
49.9Ω
Figure 19. Pulse Response for the Circuit of Figure 18
X2
Y1
8
1
0.1µF
Figure 18. Sideband DC-Coupled Multiplier
AD834
Y2 –V
X1 +V
7
2
200mV
6
3
S
S
0.1µF
4.7Ω
0.01µF
W2
W1
5
4
167Ω
3.74kΩ
0.01µF
49.9Ω
49.9Ω
3.74kΩ
3.01kΩ
14
1
OP AMP
10ns
1µF
1µF
261Ω
261Ω
7
2.7Ω
2.7Ω
8
49.9Ω
90.9Ω
AD834
LOAD
49.9Ω
+5V
–5V