ZHCS034C January 2011 – August 2018 TCA4311A
PRODUCTION DATA.
In order for the pre-charge circuitry to dampen the effect of hot-swap insertion of the TCA4311A into an active I2C bus, VCC must be applied before the SCL and SDA pins make contact to the main I2C bus. This is essential when the TCA4311A is placed on the add-on card circuit board, as in Figure 12. Although the pre-charge circuitry exists on both the -IN and -OUT side, the example in Figure 12 shows SCLIN and SDAIN connecting to the main bus. The supply voltage to VCC can be applied early by ensuring that the VCC and GND pin contacts are physically longer than the contacts for the SCLIN and SDAIN pins. If a voltage supervisor will also be used to control the voltage supply on the add-on card, additional delay will exist before the 1 V pre-charge voltage is present on the SCL and SDA pins.