890 likes | 2.93k Views
3 . Cascade and Cascode configurations (12.2 - 12.5). Cascaded amplifiers Cascode amplifiers Darlington pair Feedback pair. Cascaded amplifiers. Cascaded amplifiers consists of two or more stages of the basic BJT and/or FET circuits each of which utilize individual power supply V CC.
E N D
3. Cascade and Cascode configurations (12.2 - 12.5) • Cascaded amplifiers • Cascode amplifiers • Darlington pair • Feedback pair
Cascaded amplifiers Cascaded amplifiers consists of two or more stages of the basic BJT and/or FET circuits each of which utilize individual power supply VCC Cascaded amplifiers are used to obtain higher voltage amplification, or matching of the input impedance with the transducer and matching the output impedances with the loading of the following stage.
Example:1 (a) Find re for both BJT
(b) Find Rin, Ro, Av, and Ai of the cascade amplifier Input resistance 1 Output resistance 2 Voltage gain 1 Voltage gain 2 Voltage gain overall Current gain
Example:2 (a) Find gm of the FET
(b) Find AVT of the FET-FET cascade amplifier Input resistance 1 Output resistance 2 Voltage gain 1 Voltage gain 2 Voltage gain overall
Example:3 (a) Find re of the BJT
(c) Find AVT of the BJT-FET cascade amplifier Input resistance 1 Output resistance 2 Voltage gain 1 Voltage gain 2 Voltage gain overall
Cascode amplifiers Cascode amplifiers consists of two or more stages of the basic BJT and/or FET circuits each of which utilize single power supply VCC for both stages Cascaded amplifiers are used to obtain higher voltage amplification, or matching of the input impedance with the transducer and matching the output impedances with the loading of the following stage.
Example:4 – (page 549 text) (a) Find re (b) Find Ro2, Rin, AVT, Ai
Example:4 – (page 301 text) (a) Find VGS and gm of FET
(b) Find re (c) Find Ro2, Rin, AVT, Ai
Darlington pair DC analysis of the Darlington pair
Feedback pair DC analysis of the Feedback pair
AC analysis of the Feedback pair Rin of the Feedback pair Av of the Feedback pair Ai of the Feedback pair