EE 308 Quiz 2 Study Stuff

The advantage of a push-pull CC over a "regular" CC is:

- No source or sink current limit - No output base-emitter voltage drop - No power dissipation for open-load

MOSFET-based differential pair has tail current of 100μA; the gate overdrive of each device is 250mV. The transconductance, that relates id to vin(dm), has this approximate value:

0.2 mA/V

An op-amp uses two-stage (Miller) integrator. The integrator consists of an actively-loaded BJT diff. pair with a tail current of 25 μA, capacitor with value 50pF, and a CE stage. The slew rate of this op-amp is no larger than:

0.5 V/μs

Push-pull amplifier uses one npn and one pnp. The dead zone of this amplifier is approximately that many mili-volts:

0.6V * 2 = 1200 mV

The load of a CC amplifier is 10 kΩ (>> 1/gm). If the β of the BJT is 100, then the input resistance of the CC circuit must be on the order of:

1 MΩ

To construct "Sziklai pair" these type of devices are needed. Mark all that apply.

1 NPN and 1 PNP

Gm-C integrator is constructed using actively-loaded BJT diff. pair with a tail current of 25 μA and capacitor with value 50pF. The unity-gain frequency of this integrator is approximately that many kHz:

1.53 MHz

Two-stage (Miller) integrator is constructed using: actively-loaded BJT diff. pair with a tail current of 25 μA, a capacitor with value 50pF, and a CE stage. The frequency of the RHP zero is 10-times larger than the unity-gain frequency of the integrator. The bias current of the CE stage is approximately that many μA:

125 μA

To construct "Darlington pair" these type of devices are needed. Mark all that apply.

2 NPNs or 2 PNPs

CE amplifier has gm(eff) of 20 mA/V and β of the BJT is 50. The amplifier input resistance is no larger than:

2.5 kΩ

The differential-input linear range of a BJT differential pair is approximately that many mili-volts:

26 mV (thermal voltage), or five times the normal BJT amplifier input linear range

The load of a CC amplifier is 3 kΩ. If the biased current is 1mA, the maximum output swing (with no clipping) is:

3 V

The output resistance of a simple current mirror is 150kΩ. Two resistors of equal value are inserted in the emitters. If the voltage drop over these resistors is 75mV, the output resistance of the modified topology is approximately:

600 kΩ

CC amplifier drives 10kΩ and exhibits input resistance of 500 kΩ. If a load of 15kΩ is presented, the input resistance of this same CC circuit will become approximately:

750 kΩ

Op-amp with GBW of 2MHz implements a non-inverting amplifier with gain of 25 mV/mV. The 3-dB corner frequency of this amplifier is approximately that many kHz:

80 kHz

These single-transistor amplifiers have large (compared to 1/gm) input resistance:

Common-Collector (CC), Common-Emitter (CE)

These single-transistor amplifiers have large (compared to 1/gm) output resistance:

Common-Emitter (CE), Common-Base (CB)

These single-transistor amplifiers must be cascaded to produce a circuit that behaves as a Voltage-Controlled-Voltage-Source:

Common-Emitter, Common-Collector (CE-CC)

This single-transistor amplifier has Current Gain of approximately unity:

Common-base (CB)

This single-transistor amplifier has Voltage Gain of approximately unity:

Common-collector (CC)

This single-transistor amplifier is best characterized as a transconductor:

Common-emitter (CE)

A transconductor is another "name" for this type of a dependent source:

Voltage-controlled current source (VCCS)

A CMRR can be defined for this type of an amplifier:

differential

To create differential-input transconductor these type of circuits are needed:

differential pair, current mirror

It is claimed that an amplifier behaves as a VCVS. This therefore must be true regarding its input and output impedances:

large input impedance, small output impedance

These are (some) of the similarities between CE amplifier and CB amplifier:

large output resistance, output resistance is approximately Rc, and high voltage gain

The so-called coupling and by-pass capacitors determine this frequency:

low 3dB cutoff/corner frequency

This amplifier type might experience cross-over distortion:

push-pull

The "small-signal" behavior of a BJT in forward-active, can be characterized by the following resistive quantities: rπ, ro and 1/gm. For any practical device, this one is the largest:

ro

High-gain Amplifier consists of two CE stages connected in a cascade - the output of the first feeds the input of the second. Which of these CE stages is more likely to feature emitter degeneration?

second stage