I2C Load Capacitance ISSUE-Urgent

[ssundar.shan]

Hi,
I am interfacing my FPGA with DS2782 ("Stand-Alone Fuel Gauge IC") for I2C communication. And i have the doubt of AC Loading .
For FPGA, the output load capacitance of each pin is given as 10pF and for DS2782, the input capacitance is given as 60 pF. It seems to be Loading problem.
Will my I2C communication be proper? or Should i have to use any Fan Out buffers?

Thanks in advance.

 

[FvM]

For FPGA, the output load capacitance of each pin is given as 10pF

Where ist it "given"? An FPGA can drive different load capcitances, achieved slew rates will be respectively different.

 

[ssundar.shan]

Where ist it "given"? An FPGA can drive different load capcitances, achieved slew rates will be respectively different.

Hi,
Of-course you are correct. For I2C Communication , i am going to use +3.3V LVCMOS standard in FPGA. For this standard, the Load capacitance is specified as 10pF in FPGA Datasheet.

 

[FvM]

For this standard, the Load capacitance is specified as 10pF in FPGA Datasheet.

Means the specified timing has been measured with this load. But it's not a limit value.

 

[ssundar.shan]

Let me know about AC Loading procedure for 2 I2C devices
Let Device 1(D1) be Master and Device 2 (D2),Device 3(D3),Device 4(D4) be the slave.
Then the output capacitance of D1 id 10 pF and Input capacitance of D2, D3, D4 are 60 pF each.
Does the master has the capability to source for all the three slaves?

Thanks