Does anyone still have "Op-Amps and Linear Integrated Circuits" 013630328 and can answer Example 1-1 (b)?
At point "(b)" the author suddenly seems to pull 25mv out of the air:
re = 25mV / IEma = 25mV / 0.998mA = 25.3 ohms
Where the freek does the 25mV come from? It must be really obvious or I am just daft.
From the text:
Rc=2.2k, Re=4.7k, Rin1=Rin2=50 ohms, +VCC=10V,
-VEE=-10V, and the transistor is CA3086 with BetaAc/Dc = 100, and Vbe=0.715V typical.
(a) Determine Icq and Vceq values (this is ok) (b) Determine the voltage gain
"(b)" is what I am having difficulty with.
"(a)" was calculated as Icq = 0.988 mA Vceq = 8.54V
Figure 1-2 is roughly (use fixed font for viewing):
+VCC +-------+----------+ | | Rc Rc | | +------o vo o------+ | | +----Q1 Q2------+ | | E1 |E2 | Rin1 +--------+---------+ Rin2 | | | Vin1 RE Vin2 | | | Gnd -VEE Gnd
Where Vin1, and Vin2 are signal generators. I am unable to point to any freely downloadable "browses" of the page in question. In the hardcover 3rd edition, the exmample 1-1 is on page 25.
I can only conclude that the author thought it so obvious that he didn't see the need to include where this 25mV came from.
Snark