It also has a high-impedance collector (or drain) load, to give a large amount of signal-voltage gain (typically about 100dB).įIGURE 1. The differential amplifier has inverting and non-inverting input terminals, and has a high-impedance (constant-current) tail to give a high input impedance and good common-mode signal rejection. All of these elements are integrated on a single chip and housed in an IC package. In its simplest form, a conventional op-amp consists of a differential amplifier (bipolar or FET) followed by offset compensation and output stages, as shown in Figure 1.
The other two basic types of op-amps are the current-differencing or Norton op-amp (typified by the LM3900), and the operational transconductance amplifier or OTA (typified by the CA3080 and LM13700) these two devices will be described in some future articles. The most important of these is the conventional 'voltage-in, voltage-out' op-amp (typified by the popular 741 and CA3140 ICs), and this four-part mini-series takes an in-depth look at the operating principles and practical applications of this type of device. Three basic types of operational amplifiers are readily available. When coupled to suitable feedback networks, they can be used to make precision AC and DC amplifiers and filters, oscillators, level switches, and comparators, etc. A conventional op-amp (operational amplifier) can be simply described as a high-gain direct-coupled amplifier 'block' that has a single output terminal, but has both inverting and non-inverting input terminals, thus enabling the device to function as either an inverting, non-inverting, or differential amplifier.
0 kommentar(er)
