Logic Families
119
Figure 5.2 Input and output current specifications.
• LOW-level off-state (high-impedance state) output current, I OZL . This is the current flowing
into an output of a tristate logic function with the ENABLE input chosen so as to establish a
high-impedance state and a logic LOW voltage level applied at the output. The input conditions are
chosen so as to produce logic HIGH if the device is enabled.
• HIGH-level input voltage, V IH . This is the minimum voltage level that needs to be applied at the
input to be recognized as a legal HIGH level for the specified family. For the standard TTL family,
a 2 V input voltage is a legal HIGH logic state.
119
Figure 5.2 Input and output current specifications.
• LOW-level off-state (high-impedance state) output current, I OZL . This is the current flowing
into an output of a tristate logic function with the ENABLE input chosen so as to establish a
high-impedance state and a logic LOW voltage level applied at the output. The input conditions are
chosen so as to produce logic HIGH if the device is enabled.
• HIGH-level input voltage, V IH . This is the minimum voltage level that needs to be applied at the
input to be recognized as a legal HIGH level for the specified family. For the standard TTL family,
a 2 V input voltage is a legal HIGH logic state.