Analog IC Design Quiz

For the single-stage CMOS amplifier shown below, assume that VDD = 2.5V, RS = 50 ohm, VGS - VT = 0.2V, l = 0 V-1, and CL = 10pF. Also, ignore the device capacitance and assume that the bandwidth is dominantly contributed by the loading capacitance CL. What is the equations for Low-frequency small-signal gain vo/vi in terms of ID and RL?

• vo/vi = 2IDRL

• vo/vi = 10IDRL

• vo/vi = ID / RL

• vo/vi = 2ID / RL

What is the equations for -3dB bandwidth?

• w-3db = RLCL

• w-3db = 1 / (2RLCL)

• w-3db = 1 / (RLCL)

• w-3db = 2 / (RLCL)

What is the equations for DC power?

• p = VddID / 2

• p = 2VddID

• p = Vdd2/ RL

• p = VddID

Design the bias current ID and the load resistor RL to achieve all the following parameters at the same time: Low-frequency small-signal gain vo/vi of ≥ 20V/V.

• IDRL ≥ 20

• IDRL ≥ 2

• IDRL ≤ 20

• IDRL ≤ - 2

What is the -3dB bandwidth of ≥ 800KHz?

• RL ≤ 19.9kΩ

• RL ≤ 5152kΩ

• RL ≤ 199kΩ

• RL ≤ 39.8kΩ

What is the DC power of ≤ 3mW?

• ID ≤ 15mA

• ID ≤ 1.3mA

• ID ≤ 12mA

• ID ≤ 1.2mA

The small signal hybrid-π parameters for the BJT transistor used in the amplifiers in Fig.3(a) and Fig.3(b) are tabulated below: gm 0.01 Siemens, rπ 10 kΩ, Cπ 2 pF, Cμ 1 pF. Determine the DC voltage gain of the amplifier in Fig.3(a).

• Ao = -83.33

• Ao = 83.33

• Ao = -16.67

• Ao = 16.67

If you want to limit the bandwidth of the amplifier in Fig.3(a) to 10 kHz, what should be the value of CF used?

• CF = 94.5 pF

• CF = 593pF

• CF = 93.5 pF

• CF = 189 pF

If the CF in (ii) is now connected across the base and emitter of the transistor as shown in Fig.3(b), determine the bandwidth of this amplifier.

• 1782kHz

• 891kHz

• 446kHz

• 1337kHz

Change the value of CF in Fig.3(b) so that the bandwidth of this amplifier is again 10 kHz.

• CF = 1.74nF

• CF = 14.7nF

• CF = 17.4nF

• CF = 16.5nF