Electrical & Electronics Engineering / Multiplexers & Decoders
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LABORATORY 21 · ELECTRICAL & ELECTRONICS ENGINEERING

Multiplexers & Decoders lab report

A worked multiplexers & decoders lab report with sample observation tables, regression plots, calculations, and error analysis.

WORKED EXAMPLE · BENCHMARK OBSERVATIONS

A complete example electrical engineering laboratory report.

Simulated demonstration data.

This report illustrates formal electrical engineering data reduction, instrument calibration tares, and circuit parameter estimation. Replace its observations with your own experimental telemetry when preparing an electrical engineering laboratory report submission.

Student: __________________Student ID: __________________Course: __________________Date: __________________Partner: __________________Instructor: __________________

1. Title and aim

Multiplexers, Demultiplexers, Decoders, and Combinational Data Routing Networks. Implement combinational logic functions, data multiplexing (74151 8:1 MUX), address decoding (74138 3:8 Decoder), and priority encoding with verified timing diagrams.

2. Abstract

Laboratory evaluation of Multiplexers, Demultiplexers, Decoders, and Combinational Data Routing Networks was conducted across six calibrated setpoints. Measured telemetry was linearized, yielding a correlation coefficient R² = 1.000000. The experimental parameter Decoder Tree Stage Delay Coefficient was estimated as 0.9500 ns/line, comparing against the reference benchmark of 0.9500 ns/line with a relative percentage deviation of 0.0000%.

3. Apparatus and fixed settings

4. Theory and graph choice

The experimental analysis of multiplexers, demultiplexers, decoders, and combinational data routing networks investigates the electrotechnical behavior of data selector & demultiplexer test bench. This university laboratory module focuses on shannon's expansion theorem, bus multiplexing & address decoding trees, establishing accurate mathematical transfer characteristics across standard operational domains.

Delay = 0.9500 · N + 5.2000

Plotting Address bit depth N (lines) on the horizontal axis and Data routing path delay (ns) on the vertical axis yields a linear characteristic whose slope verifies the Multiplexers & Decoders analytical model.

5. Method

  1. Inspect all circuit connections, breadboard jumpers, and terminal blocks. Verify that instrument ground planes are tied to earth and execute zero tare on all digital meters.
  2. Energize the regulated supply, set baseline operating thresholds, and calibrate the address depth n using the precision standard reference meter.
  3. Increment the address depth n systematically across the designated experimental range (1 to 6 lines), permitting thermal settling at each setpoint.
  4. Record the primary output metric (Data Routing Path Delay) alongside auxiliary telemetry. Verify waveform symmetry, DC offset, and harmonic integrity on the oscilloscope.
  5. Execute repeated forward and reverse sweeps to detect hysteresis, thermal drift, or non-linear saturation effects across the device under test (DUT).
  6. Reduce source excitation smoothly to zero, de-energize all primary supplies, discharge residual capacitive elements, and export raw telemetry to the data buffer.

6. Observations and calculation table

All electrical engineering observations use strictly controlled 64-bit IEEE 754 precision buffers. Residuals are computed relative to the ordinary least-squares regression line.

Table 1. Six simulated observations; x and y represent transformed electrical engineering metrics.
No.Address Bit Selection Depth N (lines)Data Routing Path Delay (ns)Address bit depth N (lines)Data routing path delay (ns)Fitted yResidual
11.06.151.00006.15006.1500-0.0000
22.07.12.00007.10007.1000-0.0000
33.08.053.00008.05008.05000.0000
44.09.04.00009.00009.00000.0000
55.09.955.00009.95009.9500-0.0000
66.010.96.000010.900010.90000.0000

Download the sample observations (CSV) ↓

7. Worked calculation for one observation

x = 1.0000; y = 6.1500; fitted_y = 0.9500 · x + 5.2000 = 6.1500

8. Graph, gradient and final calculation

0.755.911.856.962.958.004.059.055.1510.096.2511.14Address bit depth N (lines)Data routing path delay (ns)

Circular markers represent empirical circuit observations. The solid line represents the ordinary least-squares linear fit.

x̄ = 3.5000; ȳ = 8.5250
Σ(x − x̄)² = 17.5000
Σ(x − x̄)(y − ȳ) = 16.6250
m = Σ(x − x̄)(y − ȳ) / Σ(x − x̄)² = 0.95000000
b = ȳ − mx̄ = 5.20000000
Decoder Tree Stage Delay Coefficient = 0.95000 ns/line

9. Uncertainty and comparison

Percentage difference = |estimate − theoretical value| / |theoretical value| × 100 = 0.0000%.

For n = 6 observations, Σresidual² = 7.100e-30; s² = Σresidual²/(n − 2). Gradient standard error = √[s²/Σ(x − x̄)²] = 3.185e-16. Intercept standard error = √[s²(1/n + x̄²/Σ(x − x̄)²)] = 1.240e-15.

Propagating the fit parameters yields a fit standard error of 3.185e-16 ns/line, with an ideal coefficient of determination R² = 1.000000.

Instrumental and regression uncertainty for Multiplexers & Decoders is constrained within 0.02% of full-scale calibration standards.

10. Result and discussion

Decoder Tree Stage Delay Coefficient = 0.9500 ns/line
Theoretical reference value: 0.9500 ns/line

Experimental observations across all test trials demonstrate strict agreement with theoretical circuit models. OLS regression slope evaluated to 0.950000 with intercept 5.200000, validating the governing equation Delay = 0.9500 · N + 5.2000 with R² = 1.000000.

11. Precautions and limitations

Assumes ideal linear operating conditions without thermal breakdown or non-linear core saturation Calibrated using the Data Selector & Demultiplexer Test Bench under controlled temperature and 64-bit IEEE 754 precision instrumentation buffers. Ordinary least-squares regression yields R² > 0.99999.

12. Conclusion

The experimental determination of Multiplexers, Demultiplexers, Decoders, and Combinational Data Routing Networks confirmed the theoretical model within an experimental uncertainty of 0.0000%. The standard calibration protocol ensures reproducible laboratory characterization.

In-Depth Technical Supplement & Circuit Engineering Derivation

1. Title and Objective

Multiplexers, Demultiplexers, Decoders, and Combinational Data Routing Networks. Implement combinational logic functions, data multiplexing (74151 8:1 MUX), address decoding (74138 3:8 Decoder), and priority encoding with verified timing diagrams. This formal laboratory report documents experimental data acquisition, mathematical model calibration, regression analysis, and error propagation for multiplexers & decoders.

2. Abstract

An experimental investigation of multiplexers & decoders was conducted using precision laboratory instrumentation across six systematic setpoints of address depth n ranging from 1 to 6 lines. Measured data routing path delay data were logged using 6.5-digit digital multimeters and digital storage oscilloscopes. Ordinary least-squares regression yielded an empirical calibration line of Delay = 0.9500 · N + 5.2000 with a coefficient of determination R² = 1.000000. The derived experimental parameter Decoder Tree Stage Delay Coefficient was evaluated as 0.95 ns/line, demonstrating complete agreement with theoretical benchmark expectations within 0.02% experimental error.

3. Experimental Apparatus & Standard Settings

  • Multiplexers & Decoders Precision Workstation: Provides regulated excitation, calibrated terminal access, and low-parasitic interconnects for shannon's expansion theorem, bus multiplexing & address decoding trees.
  • True-RMS Digital Multimeter (6.5-digit Keysight / Fluke): Measures terminal voltages, branch currents, and precision DC/AC parameters with ±0.0035% baseline accuracy.
  • Dual-Channel Digital Storage Oscilloscope (100 MHz, 1 GSa/s): Captures time-domain waveforms, phase shifts, transient dynamics, and harmonic spectra for multiplexers & decoders.
  • Regulated Linear DC / AC Variable Power Source: Supplies low-noise, ripple-free voltage and current excitation with adjustable current limiting.
  • Calibrated Decade Resistance & Component Substitution Box: Provides precision 0.1% tolerance standard passive values to establish calibrated address depth n conditions.
  • Four-Terminal Kelvin Lead Wire & BNC Coaxial Cable Set: Minimizes lead resistance, inductive pickup, and ambient EMI interference across all test ports.
  • Environmental Ambient Conditions: Ambient laboratory temperature 23.5 ± 0.5 °C; relative humidity 45 ± 5%; atmospheric pressure 101.3 kPa.
  • Excitation Calibration Settings: Primary source stabilized within ±0.01% using closed-loop linear voltage regulation.

4. Theory & Graphical Coordinate Selection

According to the principles of multiplexers & decoders, the circuit response follows the linear transformation:

Delay = 0.9500 · N + 5.2000

To evaluate the intrinsic physical parameter (Decoder Tree Stage Delay Coefficient), the experimental data are plotted with Address bit depth N (lines) on the horizontal abscissa and Data routing path delay (ns) on the vertical ordinate. The gradient of the resulting least-squares linear line directly yields the parameter magnitude.

5. Step-by-Step Experimental Method

  1. Visual Inspection & Pre-Flight Zero Tare: Inspect all circuit connections, breadboard jumpers, and terminal blocks. Verify that instrument ground planes are tied to earth and execute zero tare on all digital meters.
  2. Excitation Source & Baseline Calibration: Energize the regulated supply, set baseline operating thresholds, and calibrate the address depth n using the precision standard reference meter.
  3. Systematic Parameter Variation & Settling: Increment the address depth n systematically across the designated experimental range (1 to 6 lines), permitting thermal settling at each setpoint.
  4. Multi-Meter & Oscilloscope Waveform Acquisition: Record the primary output metric (Data Routing Path Delay) alongside auxiliary telemetry. Verify waveform symmetry, DC offset, and harmonic integrity on the oscilloscope.
  5. Cross-Validation & Redundant Trial Verification: Execute repeated forward and reverse sweeps to detect hysteresis, thermal drift, or non-linear saturation effects across the device under test (DUT).
  6. Shutdown, De-energization & Data Archival: Reduce source excitation smoothly to zero, de-energize all primary supplies, discharge residual capacitive elements, and export raw telemetry to the data buffer.

6. Raw Experimental Observations & Data Tabulation

All experimental observations were recorded under steady-state thermal and electrical equilibrium. The table below summarizes the recorded telemetry across the experimental domain.

Table 1. Experimental observation telemetry for Multiplexers & Decoders.
Trial # Address Bit Selection Depth N (lines) Data Routing Path Delay (ns) Transformed x Transformed y Residual
110.951.0000.9500.000
221.92.0001.9000.000
332.853.0002.8500.000
443.84.0003.8000.000
554.755.0004.7500.000
665.76.0005.7000.000

7. Worked Calculation for Representative Observation

For Trial 3 (Address Depth N = 3 lines):

x_3 = 3 lines
y_3 = m \cdot x_3 + b = Delay = 0.9500 · N + 5.2000
Derived Parameter Value = 0.95 ns/line

8. Regression Analysis, Gradient & Parameter Extraction

Ordinary least-squares (OLS) linear regression was performed across the six observation pairs. The regression statistics are summarized below:

Slope m = 0.9500 ns/line
Intercept b = Calculated baseline offset
Correlation Coefficient R² = 1.000000
Standard Error of Slope SE_m = ±0.00008 ns/line

9. Uncertainty Propagation & Comparison with Reference

Measurement uncertainty was calculated following the ISO Guide to the Expression of Uncertainty in Measurement (GUM). Type A uncertainty evaluated from observation residuals yielded u_A = 0.0002. Type B instrumental calibration uncertainty from the 6.5-digit multimeter was u_B = 0.0005. The combined expanded uncertainty at a 95% confidence interval (coverage factor k = 2) is:

\[ U = k \cdot \sqrt{u_A^2 + u_B^2} = 2 \cdot \sqrt{(0.0002)^2 + (0.0005)^2} = \pm 0.0011\text{ ns/line} \]

The experimental estimate of 0.95 ns/line agrees with the theoretical reference value (0.95 ns/line) within an absolute deviation of 0.015%, well within the expanded uncertainty band.

10. Engineering Discussion & Phenomenological Interpretations

The experimental results confirm the theoretical behavior of multiplexers & decoders. The linearity observed across all six test points validates the assumption of linear, bilateral network characteristics. Thermal drift was effectively suppressed by maintaining low duty cycles and utilizing precision metal-film components. The minor residual fluctuations observed are attributable to quantization resolution and Johnson–Nyquist thermal noise in the passive bridge elements.

11. Industrial Applications & Construction Practice

The electrotechnical principles demonstrated in this laboratory form the core foundation of numerous modern engineering systems, including:

  • Power Grid & Transmission Engineering: Network equivalent modeling, short-circuit current calculations, power factor correction capacitor banks, and substation protective relay coordination.
  • Consumer Electronics & Integrated Circuits: Analog front-end amplification, active Butterworth filtering, switching power supply voltage regulation, and precision ADC/DAC mixed-signal conversion.
  • Industrial Automation & Drives: Variable frequency motor speed control, servomechanism closed-loop feedback, electromechanical energy conversion, and industrial PLC signal conditioning.

12. Conclusion & Recommendations

The experimental investigation of Multiplexers, Demultiplexers, Decoders, and Combinational Data Routing Networks was completed with complete success. The linear regression model verified the governing transfer equation with R² = 1.000000. All experimental safety protocols and precision measurement guidelines were strictly observed. For future investigations, automated GPIB/USB telemetry acquisition and environmental temperature chamber testing are recommended to characterize high-temperature coefficients.

Simulated demonstration data.

This report presents simulated benchmark observations generated for demonstration and academic instruction purposes. When submitting coursework, replace all numerical values with your actual laboratory workbench observations.