Current Sources and Voltage References

Quality dual transistors

Using Precision Matched-Pairs, Duals, and Quads

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5.2 Quality dual transistors

There was a time at the beginning of the electronics era (early 1960s) that dual tran-

sistors were readily available and were even used to build early modular op amps.

Major vendors of the day included Fairchild Semiconductor, Union Carbide, Transitron,

and Motorola Semiconductors. Quality dual transistors, unlike most of the general-

purpose duals and quads that we will look at next, are matched, but to a lower degree

than the ultra-precision devices we looked at previously. They are useful in develop-

ment work and in lower accuracy applications. ...