An IR-drop is a common name for a drop of voltage occurring at the resistive component, which is caused by the resistance of interconnects constituting the network. In other words, IR-drop depends on the level of electronic resistance of some materials. Metal wires used in any design have their own resistance. When voltage is applied to the metal wires and the current starts flowing through the metal, some voltage drops.
As IR-drop is a common phenomenon, most home use electric devices have a parameter called tolerance, expressed in volts. For example, when a design requires X volts to operate, and its tolerance is Y volts, the right voltage across the power pin and ground pin should be at least equal to X-Y volts. This equation shows us that the acceptable IR-drop for this device is Y. When the voltage drop exceeds this value, the design may show some faults or its operation may not be as efficient as it should be. It often affects the timing of a device by slowing down the cell due to reduced Vdd.
Ohm’s law states that V=IR. This is the reason why exceeding the accurate level of resistance (R) or current (I) that passes through the metal layers may cause unwanted drop of voltage which is proportional to the current that flows through the conductor. The drop of voltage being a result of the previous is available at the load devices.
To avoid high IR-drop, we should use wires made of materials with lower resistance instead of others. The best way to reduce IR-drop would be to use as many as possible thick copper wires for all power connections due to the fact that this material has very small electrical resistance among other metals. Reducing the resistance value will lower the undesired IR-drop and thus it will have a positive effect on performance of a device. This way of dealing with the problem should be taken under consideration by all those who prefer to create devices at home or by other designers and manufacturers who want to achieve possibly most effective operation of their designs.
As IR-drop is a common phenomenon, most home use electric devices have a parameter called tolerance, expressed in volts. For example, when a design requires X volts to operate, and its tolerance is Y volts, the right voltage across the power pin and ground pin should be at least equal to X-Y volts. This equation shows us that the acceptable IR-drop for this device is Y. When the voltage drop exceeds this value, the design may show some faults or its operation may not be as efficient as it should be. It often affects the timing of a device by slowing down the cell due to reduced Vdd.
Ohm’s law states that V=IR. This is the reason why exceeding the accurate level of resistance (R) or current (I) that passes through the metal layers may cause unwanted drop of voltage which is proportional to the current that flows through the conductor. The drop of voltage being a result of the previous is available at the load devices.
To avoid high IR-drop, we should use wires made of materials with lower resistance instead of others. The best way to reduce IR-drop would be to use as many as possible thick copper wires for all power connections due to the fact that this material has very small electrical resistance among other metals. Reducing the resistance value will lower the undesired IR-drop and thus it will have a positive effect on performance of a device. This way of dealing with the problem should be taken under consideration by all those who prefer to create devices at home or by other designers and manufacturers who want to achieve possibly most effective operation of their designs.
