Hi,

Shonky's right, you can use a pull-up without damage.

The I2C bus allows up to 3 mA sink which at 5V is around 1.66k Ohms. This low of pull-up value would only be needed for a very capacitive load.

The amount of capacitance is determined by cable type and cable length. Coaxial cables typically have 20 pF to 30 pF per foot. Twisted Pair cables have less (12 pF to 15 pF).

The specification also specifies a maximum rise and fall time requirement based on data rate. The edge rate is degraded by the system capacitance. The capacitance degrades (rounds-off) the edges and reduces the amplitude of the signal causing errors on the I2C bidirectional bus. It can also cause loss of the first transition bit if the capacitance is very high.

For a short length of interconnect cable <10ft (around 200 pF) the 4.7k resistor should work fine. It will still preserve reasonable rise and fall time and signal level. At lengths greater than 10 ft, you might need a lower value of resistor (3.3k, 2.7k, or 2.2k) for up to 400 pF of cable capacitance. The 400 pF value is the maximum allowed in the specification, but then, there is the real world... In any case, don't go less that 1.66k per the specification.

Remember that there may be a destination termination in the monitor. This may need to be considered as a parallel resistance.

I also would not bother with a pull-down resistor at lower data rates.

Ross