TCA9617A: Can TCA9617 B side work with TCA9511? And Vol of TCA9617 B side

Hi wang,

wang fupeng said:

1. Can TCA9617 B side work with TCA9511 A side? Consider of Vol voltage. 

I don't recommend using TCA9617B with TCA9511A (either IN or OUT side). 

TCA9617B can hit max VOLB of 0.58V on B-side. The internal rise-time accelerators of the TCA9511A trigger around 0.6V. While there might be ~70 mV of margin from the typical spec, I would not recommend pairing the two buffers because the 9617B could be attempting to drive LOW while the RTA from the TCA9511A triggers HIGH. This could lead to oscillations on the I2C bus or false clock edges. 

wang fupeng said:

2. I see Vol of TCA9617 B side is 0.58v max when IoL=30mA. that means the B side driver has a 20ohm resistance, and the actual Vol will be divided with the external pull up resistor. Or the B side has a fixed Vol= 0.53?

B-side has a fixed static voltage offset of VOLB(typ) = 0.53V. When IOLB = 100 uA or 30 mA, the voltage is constant (static) across the open-drain driver. 

The external PU resistor determines the sinking current IOLB, but the sinking current does not affect the VOLB output voltage. 

Regards,

Tyler