a
FEATURES
Simple: Basic Function is W = XY + Z
Complete: Minimal External Components Required
Very Fast: Settles to 0.1% of FS in 20 ns
DC-Coupled Voltage Output Simplifies Use
High Differential Input Impedance X, Y and Z Inputs
Low Multiplier Noise: 50 nV/√Hz
APPLICATIONS
Very Fast Multiplication, Division, Squaring
Wideband Modulation and Demodulation
Phase Detection and Measurement
Sinusoidal Frequency Doubling
Video Gain Control and Keying
Voltage Controlled Amplifiers and Filters
X1
X2
250 MHz, Voltage Output
4-Quadrant Multiplier
AD835
FUNCTIONAL BLOCK DIAGRAM
X = X1 –X2
AD835
XY
∑
XY + Z
+1
W OUTPUT
Y1
Y2
Y = Y1 –Y2
Z INPUT
PRODUCT DESCRIPTION
PRODUCT HIGHLIGHTS
The AD835 is a complete four-quadrant voltage output analog
multiplier fabricated on an advanced dielectrically isolated
complementary bipolar process. It generates the linear product
of its X and Y voltage inputs, with a –3 dB output bandwidth of
250 MHz (a small signal rise time of 1 ns). Full-scale (–1 V to
+1 V) rise/fall times are 2.5 ns (with the standard R
L
of 150
Ω)
and the settling time to 0.1% under the same conditions is typi-
cally 20 ns.
Its differential multiplication inputs (X, Y) and its summing in-
put (Z) are at high impedance. The low impedance output volt-
age (W) can provide up to
±
2.5 V and drive loads as low as
25
Ω.
Normal operation is from
±
5 V supplies.
Though providing state-of-the-art speed, the AD835 is simple
to use and versatile. For example, as well as permitting the addi-
tion of a signal at the output, the Z input provides the means
to operate the AD835 with voltage gains up to about
×10.
In
this capacity, the very low product noise of this multiplier
(50 nV√Hz) makes it much more useful than earlier products.
The AD835 is available in an 8-pin plastic mini-DIP package
(N) and an 8-pin SOIC (R) and is specified to operate over the
–40°C to +85°C industrial temperature range.
1. The AD835 is the first monolithic 250 MHz four quadrant
voltage output multiplier.
2. Minimal external components are required to apply the
AD835 to a variety of signal processing applications.
3. High input impedances (100 kΩ 2 pF) make signal source
loading negligible.
4. High output current capability allows low impedance loads
to be driven.
5. State of the art noise levels achieved through careful device
optimization and the use of a special low noise bandgap volt-
age reference.
6. Designed to be easy to use and cost effective in applications
which formerly required the use of hybrid or board level
solutions.
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
© Analog Devices, Inc., 1994
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
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