Amplifier Darlington

This amplifier has two problems. The first is that most op-amps cannot drive this push-pull amplifier when it is driving an 8 2 load. The second is that the transistors turn on and off. This adds a phase delay, which can cause the amplifier to oscillate. The Darlington push-pull amplifier on page 373 works much better. ... 

EXERCISE B-13 Find the distortion of the Darlington push-pull amplifier shown below ... 

Fig. 20 Schematic of the electronics module controlling the CWBP. DA -darlington amplifiers, DAC -digital to analog converter, ADC - analog to digital converter, Amp-disc -amplifier discriminator for the photomultiplier (PMT), PS -pulse stretcher, OSC -oscillator, Zero pos - zero position sensor, Top pos -dip probe position sensor, RM - carousel rotary stepper motor, UPM - linear actuator for the dip probe of the carousel, RT - resistance thermistor, TEC -thermoelectric heat exchanger, Tset - set temperature. (Reprinted from Dhadwal et al. [2], with permission of Elsevier)...

One transistor can feed its amplified signal directly to another, and this is called the Darlington circuit, named after its innovator. If each transistor has a gain of about 100, the overall gain is about 10,000. They can be bought in a single... 

---