## Thursday 9 February 2023

### Computation of Target IR Drop Value

IR drop is the voltage drop that occurs in the power distribution network due to the resistance and inductance of the interconnects and packages. In physical design, the target IR drop value is a desired value that is set to ensure the reliability and performance of the circuit.

To compute the target IR drop value in the core from the target IR drop value, the following steps can be followed:

Determine the target voltage drop: The target IR drop value is specified as a voltage drop across the power distribution network. The target voltage drop can be determined by subtracting the desired supply voltage from the nominal voltage of the power distribution network.

Determine the power density: The power density of the core can be estimated based on the power consumption of the circuit and the area of the core.

Estimate the resistance and inductance: The resistance and inductance of the power distribution network can be estimated based on the interconnect metal stack and the package parasitics.

Calculate the current: The current in the power distribution network can be calculated based on the power density and the voltage drop.

Calculate the target IR drop: The target IR drop value can be calculated by multiplying the current by the resistance and inductance of the power distribution network.

By computing the target IR drop value in the core from the target IR drop value, the power distribution network can be designed to meet the desired performance and reliability requirements.