Arhiva Hewlett-Packard
Scris: Lun Mar 01, 2021 4:38 am
Despre cei 26 mV ( valoare optimă ) de pe rezistența de emitor la amplificatoarele ce funcționează în clasa AB cu etaj final având tranzistoare finale bipolare :
" The paper was in the Hewlett-Packard Journal and is reproduced in The Selected Papers of Bernard Oliver, pp. 311-317. I have that book handy for a change
An excerpt: "However, the drop across this resistance produced by the operating current is only Io/2go = 1/2 kT/q to Io/go = kT/q or from 13 to 26 millivolts. Over the temperature ranges from 0 C to 100 C, the junction drop of a silicon transistor will change typically by 250 mV, Thus, unless the biasing diodes ... track this change within a few percent, Io will be very unstable ... At present the most practical solution to the temperature stability problem appears to be to make Rc [the emitter resistors] many times larger than 1/go, and to rely on negative feedback to reduce the resulting distortion."
Also in the collection is his great paper Thermal and Quantum Noise, from Proc. IEEE, May 1965. "