Hi there,
Here is a customer question regarding the device behavior during power up:
Our design involves the use of multiple SN74AVC2T245RSWR on a connector between two circuit assemblies. The driver assembly has an FPGA with a 2.5V output, and the SN74AVC2T245RSWR is located on the receiving assembly over a short (4") ribbon cable. At times during unit test, only one of the two assemblies will be powered on. The ports never change direction, so we have DIR tied high through a 10K resistor, and the B's are used as an output. Both VCCA and VCCB come from the board hosting the SN74AVC2T245RSWR, and are not supplied over the interface. Here are my questions:
1. The datasheet says that all of the outputs will be in the high-impedance state if either supply is ground. What happens as the power supply is ramping up?
2. Is it safe if the inputs (A pins) receive 2.5V from the FPGA if neither supply (VCCA or VCCB) is on?
