Timeline for Simple power amplifier with feedback - designing procedure
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 17, 2020 at 20:31 | history | edited | G36 | CC BY-SA 4.0 | added 106 characters in body |
| Dec 17, 2020 at 20:22 | history | edited | G36 | CC BY-SA 4.0 | added 318 characters in body |
| Dec 17, 2020 at 20:05 | comment | added | G36 | You are right about the Ry (R3) resistor influence on Rin resistance. But typically R3 will have a value more than 10 times Rt1 so we can ignore the R3 influence. | |
| Dec 17, 2020 at 19:48 | comment | added | Dawid W | \$R3\$ would be of course a second resistor of a biasing voltage divider (not shown at current diagram) | |
| Dec 17, 2020 at 19:44 | vote | accept | Dawid W | ||
| Dec 17, 2020 at 19:44 | comment | added | Dawid W | Perfect! Thank You, \$3.8k\$ is exactly the value I came up with through simulation. I suspected it has something to do with input impedance and a voltage divider but I would never come up with Miller's theorem myself here and no, I am not going to build exactly THIS amplifier - I deliberately simplified it for analysis purposes and omitted some blocks like bias servo, source current, emitter resistors etc. One more thing - would it be any different if I used a voltage divider instead of single \$R1\$ resistor to bias \$T1\$? Would imput impedance be \$Rm||R3||RT1\$? | |
| Dec 17, 2020 at 19:09 | history | edited | G36 | CC BY-SA 4.0 | edited body |
| Dec 17, 2020 at 18:56 | history | answered | G36 | CC BY-SA 4.0 |