The measurement system depicted in the figure below consists of a resistive Wheatstone bridge excited by a dc current. To establish the excitation current in this configuration, a zener diode is employed, with . The zener is considered here as an ideal device, operating in regulation with a current through its terminals of 5.3 mA.

Assume , , , . In the Wheatstone bridge consider and  mΩ/Ω.

Determine the common-voltage at the bridge output (i.e., the common-mode voltage of and ).

Consider the following circuit where the node represents the low-impedance output of a sensor, with a linear operating range of .

The requirement is to convert this input voltage range to an output voltage range of . Determine the most suitable value for the Zener voltage.

Consider a regulated voltage output, which needs to be checked. Three dc digital bench voltmeters (DVM) are available (red DVM-1, green DVM-2, and blue DVM-3). Find which one provides the best measurement uncertainty, i.e. in the reading result , and provide the value of the uncertainty found only for that DVM.

The first DVM provided the reading , whereas the second shown , and finally, the third gave .

The accuracy performance is summarized below.

The circuit shown in figure employs a type-B thermocouple with Seebeck coefficient , applied in a glass production system for measuring furnace temperatures during glass melting and forming processes.

To compensate the cold junction, an integrated analog circuit is used, providing a proportional-to-absolute temperature (PTAT) current given by , where is the temperature in °C, , and .

What is the value of that compensates the cold junction?

Consider the following circuit in which the thermistor NTC has at and .

Determine the output voltage when the temperature is .

The Wien bridge shown in the figure is used as a null frequency detector when driven by an ac voltage.

Adjusting and , there is a null detection observed when and .

The standard capacitors (fixed-value) are , and .

Determine the detected null frequency.

The universal digital counter, with the simplified diagram representation shown below, is operating as a frequency meter. The oscilator frequency is and the decade divider provides the time-base selection of frequency signals , .

Assuming an input signal with frequency , what is the number of pulses obtained by the decade counter when the most adequate time base has been chosen?

Consider the following digital-to-analog converter (DAC), which uses a 3-bit word () to control which of the switches turns on (’1’ means closed) while all the others are kept turned off (’0’ means opened). For this end, it uses a decoder that converts each input to a 8-bit word () by means of one-hot encoding (only a single bit is ’1’).

Assuming the reference voltage , what is the analog output voltage for a binary input 101.

Consider a bits bipolar ADC (rail-to-rail, ) in which the measured signal to noise-and-distorion ratio (SINAD) is for an input signal , where is much lower than the sampling frequency (the RC filter does not affect the signal, it only removes high-frequency noise) and .

Determine the effective number of bits (ENOB) of the ADC.

In the following analog-to-digital converter (ADC), employing a half-flash architecture, consider , , and uniform mid-rise quantizers in the flash ADCs.

Obtain the analog voltage at the output of the residue amplifier, indicated as in the figure.