Noise Margin [Short Notes] |UGC NET Aspirants (Electronic Science) |Explained in HINDI

[@srajanikapaintings530]

Good

[@DeepaSingh-ul5kb]

nice

[@avinasha237]

At 3:29 in the diagram Noise margin at low will happen to be negative results in failure in operation and Noise margin for high is positive. Why such a diagram is taken for this 🤔

[@avinasha237]

Do I miss any concept here?

[@VersatileElectronicScience]

1. Noise Margins in Practice:
o The text mentions that noise margins are the amount of noise that a logic circuit can withstand. In the diagram, this is represented by NM_H (High Noise Margin) and NM_L (Low Noise Margin). These margins define the tolerance levels for high and low signals against noise interference.
2. Positive and Negative Values of Noise Margins:
o The text explains that positive noise margin values ensure proper operation, while negative values result in compromised operation or outright failure.
o In the diagram:
 Positive Noise Margins: The noise margins (NM_H and NM_L) are positive when V_OH >V_IH and V_OL

[@VersatileElectronicScience]

The diagram illustrates noise margins and the indeterminate region in digital circuits, focusing on how noise affects signal integrity between two devices, A and B, typically digital logic gates or buffers.
Key Elements in the Diagram:
1. Top Part - Signal Transmission with Noise:
o Device A (left side): This represents the output device, which sends a signal to Device B.
o Device B (right side): This represents the input device receiving the signal from A.
o The line between A and B indicates a signal transmission path, which is affected by noise (as denoted by the label "Noise").
o Voltage Levels:
 At the output of Device A: V_OH (Output High Voltage) and V_OL (Output Low Voltage) are the defined high and low output voltage levels.
 At the input of Device B: V_IH (Input High Voltage) and V_IL(Input Low Voltage) are the thresholds defining what B interprets as high or low signals.
2. Voltage Threshold Relationships:
o Device A's output voltage levels (V_OH and V_OL) must match up appropriately with Device B's input thresholds (V_IH and V_IL).
o Correct operation requires that V_OH ≥ V_IH and V_OL ≤ VIL.
3. Bottom Part - Noise Margins and Indeterminate Region:
o Output vs. Input Voltage Plot:
 The plot maps V_out (output voltage from A) against V_in (input voltage to B).
 V_OH and V_OL represent the output high and low voltage levels.
 V_IH and V_IL represent the input high and low voltage thresholds.
o Noise Margins:
 NM_H(High Noise Margin): The difference between V_OH and V_IH. It represents the tolerance to noise when the signal is high.
 NM_L(Low Noise Margin): The difference between V_IL and V_OL. It represents the tolerance to noise when the signal is low.
o Indeterminate Region:
 This region lies between V_IH and V_IL, where the signal is not clearly defined as high or low.
 If the input voltage falls within this region, Device B cannot reliably determine the signal state, leading to potential errors in digital logic interpretation.
Summary:
• The diagram highlights the importance of maintaining sufficient noise margins to ensure reliable communication between digital devices.
• The indeterminate region poses a risk as signals that fall into this range may be misinterpreted due to noise, underscoring the need for proper design to minimize such occurrences.

[@avinasha237]

​@@VersatileElectronicScience at 2:14 the equations for
NM_H = VO_H(min) - VI_L(min) means NM_H is positive when VO_H > VI_L and NM_L = VO_L (max) - VI_L(max) which means NM_L is positive for VO_L > VI_L

[@avinasha237]

​​@@VersatileElectronicScience at 2:14 kindly look at the equation in the box for NM. Also the figure also makes sense for positive NM