TCAN1046V-Q1: About the start-up order of VIO and VCC

Hi Koji-san,

There is no required power-up order for TCAN1046V-Q1. The bus pins of the device will remain high-impedance until both Vcc and Vio are sufficiently supplied. This is to ensure that the bus is not disrupted during device power-up. Once the threshold is met at both supplies and the transceiver enters normal mode (with STB = low) the transceiver will attempt to drive a dominant pulse on the bus when TXD is driven low. For this reason, it is important that the CAN controller does not inadvertently drive the TXD line low during its power-up sequence. The TXD input has an internal pull-up to Vio so this pin is biased recessive (high) when Vio is initially supplied for the case that the controller pin is initially high-impedance. 

Let me know if you have any more questions.

Regards,
Eric Schott