AD704

Features:

High DC Precision
150 pA max Input Bias Current
0.2 pA/8C typical IB Drift
chips & MIL-STD-883B Processing Available
Available in Tape and Reel in Accordance with EIA-481A Standard
Single Version: AD705, Dual Version: AD706




Application

Industrial/Process Controls
Weigh Scales
ECG/EKG Instrumentation
Low Frequency Active Filters




Pinout






Specifications

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18 V
Internal Power Dissipation (+25°C) . . . . . . . . . . . See Note 2
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±VS
Differential Input Voltage³. . . . . . . . . . . . . . . . . . . . . . . ±0.7 V
Output Short Circuit Duration (Single Input) . . . . .Indefinite
Storage Temperature Range(Q) . . . . . . . . . . 65°C to +150°C
(N, R) . . . . . . . . . . . . . . . . . . . . . . . . . . . 65°C to +125°C
Operating Temperature Range
AD704J/K . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
AD704A/B . . . . . . . . . . . . . . . . . . . . . . . . . 40°C to +85°C
AD704T . . . . . . . . . . . . . . . . . . . . . . . . . .55°C to +125°C
Lead Temperature Range (Soldering 10 seconds) . . . . +300°C






Description

The AD704 is a quad, low power bipolar op amp that has the low input bias current of a BiFET amplifier but which offers a significantly lower IB drift over temperature. It utilizes Superbeta bipolar input transistors to achieve picoampere input bias current levels (similar to FET input amplifiers at room temperature), while its IB typically only increases by 5* at +125°C (unlike a BiFET amp, for which IB doubles every 10°C resulting in a 1000* increase at +125°C). Furthermore the AD704 achieves 75 µV offset voltage and low noise characteristics of a precision bipolar input op amp.

Since it has only 1/20 the input bias current of an AD OP07, the AD704 does not require the commonly used "balancing" resistor. Furthermore, the current noise is 1/5 that of the AD OP07 which makes the AD704 usable with much higher source impedances. At 1/6 the supply current (per amplifier) of the AD OP07, the AD704 is better suited for today's higher density circuit boards and battery powered applications. The AD704 is an excellent choice for use in low frequency active filters in 12- and 14-bit data acquisition systems, in precision instrumentation, and as a high quality integrator. The AD704 is internally compensated for unity gain and is available in five performance grades. The AD704J and AD704K are rated over the commercial temperature range of 0°C to +70°C. The AD704A and AD704B are rated over the industrial temperature of 40°C to +85°C. The AD704T is rated over the military temperature range of 55°C to +125°C and is available processed to MIL-STD-883B, Rev. C.