AD835

A two- or four-quadrant multiplier can be configured to simulate a resistor with a value that is the ratio of a fixed resistor and a control voltage. If the voltage-controlled current source is made to depend on input voltage V_in (i.e.by driving Y2), as well as being allowed to "float" on top of V_in(i.e. by connecting Y2 to Z), then the input of Y2 will simulate a resistor with the transfer function R_in= R(U/E_c). One node of the simulated resistor will always be referred to ground.

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 RL of 150 W) and the settling time to 0.1% under the same conditions is typically 20 ns.

Its differential multiplication inputs (X, Y) and its summing input (Z) are at high impedance. The low impedance output voltage (W) can provide up to ±2.5 V and drive loads as low as 25 W. 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 addition 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 nVHz) 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.