Active device is the main device of electronic circuit. From the physical structure, circuit function and engineering parameters, active devices can be divided into two categories: discrete devices and integrated circuits.
1. Discrete devices
(1) bipolar transistor
(2) field effective transistor
(4) Semiconductor resistance and capacitance —— resistors and capacitors manufactured by integrated technology for integrated circuits.
2. Analog IC Devices
Analog integrated circuit devices are integrated circuit devices used to process analog voltage or current signals
Basic analog IC devices generally include:
(1) operation amplifier
3) Logarithmic and exponential amplifiers
(5) analog switch
(6) phase lock loop
(7) voltage regulator
(8) reference source
(9) wave-form generator
(10) power amplifier
3. Digital integrated circuit devices
(1) logic gate circuit
(8) shaping circuit
(12) digital signal processor，dsp
Active device is the key to electronic circuit. All oscillation, amplification, modulation, demodulation, and current conversion are inseparable from active components.