Logic Gates and Related Devices
97
I IH
I IH
I IH
I IH
I IH
I IH
OFF
(a)
I IL
I IL
ON
(b)
OFF
I IL
I IL
I IL
I IL
I OL
I
+V
+V
+V
+V
+V
+V
+V
+V
I OH
ON
Figure 4.39 Fan-out of the standard TTL logic family.
Example 4.14
A certain logic family has the following input and output current specifications:
1. The maximum output HIGH-state current = 1 mA.
2. The maximum output LOW-state current = 20 mA.
3. The maximum input HIGH-state current = 50 A.
4. The maximum input LOW-state current = 2 mA.