OP-297

The OP-297 is the first dual op ampto pack precision performance into the space-saving, industry standard 8-pin SO package.Its combination of precision with low power and extremely low input bias current makes the dual OP-297 useful in a wide variety of applications.Combining precision, low power and low bias current, the OP-297 is ideal for a number of applications including instrumentation amplifiers, log amplifiers, photo-diode preamplifiers and longterm integrators. For a single device, see the OP-97; for a quad,see the OP-497.

Features of the OP-297 are:(1)precision performance in standard SO-8 pinout; (2)low offset voltage:50V max; (3)low offset voltage drift:0.6V/ max; (4)very low bias current:+25:100pA max,-55to +125:450pA max; (5)very high open-loop gain:2000V/mV min; (6)low supply current (per amplifier) : 625A max; (7)operates from ±2V to ±20V supplies; (8)high common-mode rejection:120dB Min; (9)pin compatible to LT1013, AD706, AD708, OP-221,LM158, and MC1458/1558 with improved performance.

The absolute maximum ratings of the OP-297 can be summarized as:(1)supply voltage:±20V;(2)storage temperature range:-65 to +175;(3)operating temperature:-40 to 85;(4)lead temperature:300;(5)different input voltage:40V;(6)input voltage:±20V.To maintain the extremely high input impedances of the OP-297,care must be taken in circuit board layout and manufacturing.Board surfaces must be kept scrupulously clean and free of moisture. Conformal coating is recommended to provide a humidity barrier. Even a clean PC board can have 1 OOpA of leakage currents between adjacent traces, so guard rings should be used around the inputs.Guard traces are operated at a voltage close to that on the inputs, as shown in Figure 4, so that leakage currents become minimal. In noninverting applications, the guardring should be connected to the common-mode voltage at the inverting input. In inverting applications, both inputs remain at ground, so the guard trace should be grounded.Guard traces should be on both sides of the circuit board.