ꢀ ꢁꢂ ꢃꢄ ꢅꢆ ꢃꢅ
ꢇꢈ ꢉꢈ ꢊꢋꢌ ꢀꢈ ꢉ ꢍꢋꢌ ꢎꢏ ꢐ ꢆꢑ ꢀ ꢀꢐ ꢏ
SGUS014H − FEBRUARY 1991 − REVISED JUNE 2004
PARAMETER MEASUREMENT INFORMATION (CONTINUED)
signal transition levels
TTL-level outputs are driven to a minimum logic-high level of 2.4 V and to a maximum logic-low level of 0.6 V.
Output transition times are specified as follows:
D
D
For a high-to-low transition on a TTL-compatible output signal, the level at which the output is said to be
no longer high is 2 V and the level at which the output is said to be low is 1 V.
For a low-to-high transition, the level at which the output is said to be no longer low is 1 V and the level at
which the output is said to be high is 2 V.
2.4 V
2 V
1 V
0.6 V
Figure 5. TTL-Level Outputs
Transition times for TTL-compatible inputs are specified as follows:
D
D
For a high-to-low transition on an input signal, the level at which the input is said to be no longer high is
2.1 V and the level at which the input is said to be low is 0.8 V.
For a low-to-high transition on an input signal, the level at which the input is said to be no longer low is
0.8 V and the level at which the input is said to be high is 2.1 V.
2.1 V
0.8 V
Figure 6. TTL-Level Inputs
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