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SN74HCS245: How to understand VT+

Part Number: SN74HCS245


For example, for 4.5V supply, input logic level is 3.3V, as datasheet said, VT+ range is 1.7V min to 3.15V max, so could it consider 3.3V input as a logic high?


  • All voltages above VT+ are considered high. However, with a 5 V supply, the maximum VT+ is 3.5 V, and the tolerances of your power supply might shift it even higher.

    To convert from 3.3 V to 5 V, use a device with TTL-compatible inputs (AHCT, HCT), or a level shifter.