TXB0104 4-Bit Bidirectional Voltage-Level Shifter Texas Instruments TXB0104 4-Bit Bidirectional Voltage-Level Shifter uses two separate configurable power-supply rails. The A port is designed to track VCCA. VCCA accepts any supply voltage from 1.2V to 3.6V. The B port is designed to track VCCB. VCCB accepts any supply voltage from 1.65V to 5.5V. This feature allows for universal low-voltage bidirectional translation between any of the 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, and 5V voltage nodes. VCCA must not exceed VCCB.