ZHCS034C January 2011 – August 2018 TCA4311A
PRODUCTION DATA.
When a logic low voltage, VLOW1, is driven on any of the TCA4311A's data or clock pins, the TCA4311A regulates the voltage on the other side of the chip (call it VLOW2) to a slightly higher voltage, as directed by the following equation:
where R is the bus pull-up resistance in ohms (Ω). For example, if a device is forcing SDAOUT to 10 mV where VCC = 3.3 V and the pull-up resistor R on SDAIN is 10 kΩ, then the voltage on SDAIN = 10 + 75 + (3.3/10000) × 100 = 118 mV. See the Typical Characteristics section for curves showing the offset voltage as a function of VCC and R.