Silicon Die Packaging Separation under Legacy Line Retrenchment
Legacy line retrenchment forces silicon die packaging changes that alter kerf tolerances, land patterns, register offsets, and landed unit economics.
I2C Pull up Sizing
Resistor Selection
Calculation of the appropriate resistance value needed to pull a bidirectional communication line to the supply voltage. Proper i2c pull up sizing balances the need for fast signal rise times against the requirement to stay within the current sinking capabilities of the bus drivers. Smaller resistors provide faster transitions but consume more power.
Rise Time
Passive pull up transitions follow an exponential curve determined by the bus capacitance and the resistor value. Engineers perform i2c pull up sizing to ensure the signal reaches the logic high threshold before the next clock edge. If the resistance is too high, the bus becomes sluggish and data errors occur.
Current Limit
Drivers must be able to pull the line low without exceeding their rated maximum current. During i2c pull up sizing, the minimum resistance is calculated by dividing the supply voltage by the maximum sink current of the weakest device on the bus.
System Efficiency
Battery powered devices require a careful trade off between signal speed and energy consumption. Verification of i2c pull up sizing involves measuring the actual rise times on a fully loaded bus across the operating temperature range. A well chosen value ensures robust communication without wasting power.