Question 7.12: In a data acquisition system 64 signals are scanned sequenti...

Analogue Electronic Circuits and Systems

In a data acquisition system 64 signals are scanned sequentially and are connected to an analogue-to-digital converter via nine multiplexers as shown in Fig. ex.7.12(a). Each one has eight input channels. The leakage current is 10 nA when a switch is at ‘off’ state. The ‘on’ resistance of the switch $r_{on}$ is $250 \Omega$ . The output capacitance of each multiplexer is 50 pF. Calculate the static error and approximate settling time if a dynamic error of 0.1% is allowed.

IMG_20220416_233922

The "Step-by-Step Explanation" refers to a detailed and sequential breakdown of the solution or reasoning behind the answer. This comprehensive explanation walks through each step of the answer, offering you clarity and understanding.
Our explanations are based on the best information we have, but they may not always be right or fit every situation.

The blue check mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

This Question has been Answered.

Already have an account?

Related Answered Questions

Question: 7.16

In order to analyse a complex waveform the data acquisition system shown in Fig. ex.7.16 is used. The error sources and average errors in percentage are given in Table 7.1. The systematic errors due to temperature change and power supply variation can be neglected. Assuming that the random errors ...

Verified Answer:

Add the average errors algebraically.

0.005...

Question: 7.15

The sample-and-hold circuit in Fig. ex.7.15 has the following data: C = 0.1 μF, maximum output current of the operational amplifiers = 100 mA, amplifier bias currents = 10 nA. It is used in a 10 V, 10-bit system. Calculate the acquisition time and the droop rate. If the sampleand- hold circuit is ...

Verified Answer:

From (7.19)

d V^{+} _{c} /dt= (I_{max}- I_{...

Question: 7.14

The circuit in Fig. ex.7.14 is connected to a source with an output impedance of 600 Ω. The ‘on’ resistance of the FET switch is 250 Ω. The bias current of the operational amplifier is 50 pA. Find the acquisition time to 1 % for a 10 V change in the output if the value of the capacitor is 0.01 μF ...

Verified Answer:

R=R_{s} +r_{on}

t_{ac...

Question: 7.13

Sixteen 16-channel multiplexers are used in a data acquisition system as shown in Fig. ex.7.13(a). The ‘on’ resistance of the switch is 270 Ω the capacitance across the open switch is 1 pF and the output capacitance of each multiplexer is 50 pF. To achieve an accuracy of 0.1% what would be ...

Verified Answer:

The delay time is given by

t_{d}= t_{A} -t_...

Question: 7.11

A multiplexer is part of a 12-bit, 10-volt system. The CMOSFET switches have leakage currents of 45 nA and ‘on’ resistances of 450 Ω. The multiplexer output capacitance is 44 pF. All inputs are scanned sequentially, (i) Calculate the number of input channels that the multiplexer has if the maximum ...

Verified Answer:

\frac{1}{8} LSB = \frac{1}{8} \times \fra...

Question: 7.4

The digital input 11011011 applied to a RS DAC0800 causes it to produce an output current I0 =4.275 mA. Find the value of the D-to-A converter reference current and the value of the complementary output current I0. Determine also the values of I0 and I0 for the digital inputs 10000001, and 01111110. ...

Verified Answer:

I_{0}= I_{REF} [\frac{1}{2}+\frac{1}{2^{2}}...

Question: 7.10

The RS DAC0800 used in the basic voltage output DAC system of Fig. 7.9 has the following error data: zero scale current (all bits off, Izs) = 2 μA; non-linearity = ±0.19 % FS; full-scale temperature coefficient (TCIFS)= ±50 ppm/°C; power supply sensitivity (PSSIFS+ , PSSIFS_) = 0.01 %/%. The 777 ...

Verified Answer:

FSR

V_{x}= \frac{255}{256}\frac{V_{REF} }{R...

Question: 7.9

An 8-bit dual slope A-to-D converter has a clock frequency of 50 kHz. What is the conversion time for an input signal of 7.2 volts if the reference voltage is 10 volts? Assume that it takes 1.5 ms to zero the integrator. ...

Verified Answer:

conversion time

=T_{1} + T_{x}+

tim...

Question: 7.8

Calculate the time required by (i) a successive approximation type A-to-D converter and (ii) a servo type A-to-D converter to record a change in analogue voltage of 6.25 V. The frequencies of the clock pulses applied to the converters are 200 kHz and 500 kHz respectively. Both of them are 8-bit ...

Verified Answer:

(i) The conversion time for the S.A. type of A-to-...

Question: 7.7

A 4-bit successive approximation type A-to-D converter has a FSR of 10 volts. What are the bit values? If an analogue input signal of 8.3 volts is applied to the converter, what will be the binary output code? What will be the error? Draw a timing diagram for the conversion sequence. ...

Verified Answer:

MSB= \frac{V_{R}}{2}= \frac{10}{2}=5[/latex...