Sd292 Asg5

SYDE 292

Sample Exam Questions

#5

Questions: 1. An analog signal having a 0 – 10 V range is to be converted into an 8 bit digital word. What is the resolution of the conversion in volts? What is the straight binary digital representation of 6 V.? What is the error made in quantizing 6.2 V in absolute terms and as a percent of the input and as a percent of full scale? What is the largest possible quantization error as a percent of full scale? 2. If the input bias current of an op-amp used as the output summer in a 10 bit DAC, is to be no more than the equivalent of 1/4 LSB, what is the maximum current required to flow in Rf for an op-amp whose bias current is a great as .5 µA? See circuit shown below.

3. Calculate Vo for the circuit shown below

4. Calculate Vo for the circuit shown below.

5. For an input digital word of 1010 controlling the switches S1 to S4 what is the output voltage for the circuit shown below.

6. Sketch the log magnitude curve for the following transfer function.

V0 10s = Vi s + ωc

where ωc = 20,000 rad /s Design a circuit which realizes this transfer functon. 7. Design a circuit which sums two signals and multiplies the result by 3. Ensure that your circuit has a minimum input resistance of 100 kΩ and uses as few components as possible. 8. Design a two staged cascaded amplifier circuit with a gain of 121. Assuming the GBW of the op-amps used is 5 MHz. What is the bandwidth of each of your stages individually? What is the bandwidth of the over all cascaded amplifier? What would be the bandwidth of a single stage amplifier with a gain of 121? 9. A 10 mV DC signal in 1 V rms of common-mode noise is to be raised to a 1 V DC level with 10 mV rms noise. Determine the required Ad and CMRR (dB) 10. Determine the output amplifier error as a percentage of VFS (εamp%FS) for an IA operating under the following conditions: CMRR = 80 dB, Ad = 1000, Vos = .5 mV , Ios = 1 nA, Rs = 1 kΩ, constant temperature, Neglect any terms that can not be calculated.

VFS

VCM = 1 V rms, = 10 V.