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I2C Bus Pull-Up Resistor & Bus Capacitance Calculator Electronics & RF
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I2C Bus Pull-Up Resistor & Bus Capacitance Calculator

Calculate minimum and maximum I2C pull-up resistor values (Rp), bus capacitance limits (Cb), and signal rise times across Standard, Fast, and Fast-mode Plus specifications.

I2C Bus Operating Parameters

V
pF
V
mA
Allowed Resistor Range (Rp) VALID TIMING RANGE
967 Ω – 3.54 kΩ
Rp(min) = 967 Ω | Rp(max) = 3.54 kΩ
Recommended Standard Resistor (E24)
2.2 kΩ
Provides balanced rise time and drive current margin.
Bus Timing & Power Analysis
Estimated Rise Time (Tr): 186 ns (Limit: 300 ns)
Low-State Bus Current (per line): 1.32 mA
Static Power Dissipation (Low State): 3.82 mW / line

Frequently Asked Questions