SN74AXCH1T45 Dual-Supply Bus Transceivers Texas Instruments SN74AXCH1T45 Dual-Supply Bus Transceivers utilize two individually configurable power-supply rails. The power-supply rails allow each port to operate with a power supply range from 0.65V to 3.6V. The A port is designed to track VCCA, which accepts any supply voltage from 0.65V to 3.6V. The B port is designed to track VCCB, which also accepts any supply voltage from 0.65V to 3.6V.