RoHS Compliance Information	Size in Kbytes	Date
LM194/LM394 Supermatch Pair	221 Kbytes	7-Jan-96	Download
LM194 Mil-Aero Datasheet MNLM194-X	104 Kbytes		Download

Obsolete Versions

General Description

The LM194 and LM394 are junction isolated ultra well-matched monolithic NPN transistor pairs with an order of magnitude improvement in matching over conventional transistor pairs. This was accomplished by advanced linear processing and a unique new device structure.

Electrical characteristics of these devices such as drift versus initial offset voltage, noise, and the exponential relationship of base-emitter voltage to collector current closely approach those of a theoretical transistor. Extrinsic emitter and base resistances are much lower than presently available pairs, either monolithic or discrete, giving extremely low noise and theoretical operation over a wide current range. Most parameters are guaranteed over a current range of 1 µA to 1 mA and 0V up to 40V collector-base voltage, ensuring superior performance in nearly all applications.

To guarantee long term stability of matching parameters, internal clamp diodes have been added across the emitter-base junction of each transistor. These prevent degradation due to reverse biased emitter current-the most common cause of field failures in matched devices. The parasitic isolation junction formed by the diodes also clamps the substrate region to the most negative emitter to ensure complete isolation between devices.

The LM194 and LM394 will provide a considerable improvement in performance in most applications requiring a closely matched transistor pair. In many cases, trimming can be eliminated entirely, improving reliability and decreasing costs. Additionally, the low noise and high gain make this device attractive even where matching is not critical.

The LM194 and LM394/LM394B/LM394C are available in an isolated header 6-lead TO-5 metal can package. The LM394/LM394B/LM394C are available in an 8-pin plastic dual-in-line package. The LM194 is identical to the LM394 except for tighter electrical specifications and wider temperature range.

Design Tools

Title	Size in Kbytes	Date
Amplifiers Selection Guide software for Windows			View

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Application Notes

Title	Size in Kbytes	Date
AN-222: Application Note 222 Super Matched Bipolar Transistor Pair Sets New Standards for Drift and Noise	399 Kbytes	1-Oct-02	Download

More Application Notes

Title	Size in Kbytes	Date
AN-184: Application Note 184 References for A/D Converters	64 Kbytes	3-Oct-02	Download
AN-184 (Japanese): Application Note 184 References for A/D Converters	124 Kbytes
AN-161: Application Note 161 IC Voltage Reference has 1 ppm per Degree Drift	138 Kbytes	10-Oct-02	Download
AN-110: Application Note 110 Fast IC Power Transistor with Thermal Protection	333 Kbytes	3-Oct-02	Download