The output-tolerant function is designed to prevent current from flowing from an output to the power supply when the output assumes the high-impedance state or when power supply (Vcc) = 0 V.
The allowable output voltage specification is shown in the Output Voltage section of the Recommended Operating Conditions table. When input/output voltage range is 0 - Vcc, voltage in excess of Vcc must not be applied because the circuit has a diode (no output-tolerant function).
The output voltage range of LCX is 0 - 5.5V with the output in the high-impedance state (since it has a output-tolerant function); thus, up to 5.5V can be applied to the output regardless of the power supply voltage. When the Vcc = 3.3 V, LCX can be directly connected to a 5-V bus line.
The output voltage range of VCX is 0 - 3.6 V with the output in the high-impedance (since it has an output-tolerant function); thus up to 3.6 V can be applied to the input regardless of the power supply voltage. When the Vcc = 2.5 V, VCX can be directly connected to a 3.6-V bus line.
For direct connection to a bus line, however, care should be taken when a CMOS input of the subsequent-stage IC is driven by a CMOS output of the previous-stage IC because the output voltage (VOH) is close to the power supply voltage (Vcc). Ensure that the VOH of the driving IC meets the input voltage (VIH) level of the driven IC.
For the output tolerant function, please refer to application notes each series.