JEDEC – no definition offered

TI – The current flowing into an output with the input conditions applied that, according to the product specification, establishes the high-impedance state at the output

TI data sheets specify currents flowing out of a device as a negative value. The electrical characteristic, IOZ, is verified utilizing the IOZH and IOZL tests. Two tests are required to verify the integrity of both the p- and n-channel transistors.

For bidirectional I/O that have bus hold on the data input/output pins, there should not be an IOZ specification because the bus-hold output supplies enough current to overcome any internal output leakage.

An exception to this is an IOZH specification for an overvoltage-tolerant bus-hold output with a test condition of VO >> VCC. This is used to indicate that the overvoltage-tolerant bus-hold output has a Schottky blocking diode in series with the output p-channel pullup transistor to VCC and Ioff circuitry, preventing the upper p-channel from turning on, which prevents current from flowing from the output back into the VCC supply. See II(hold) and Ioff for more information.