In the figure, we show the way in which integrated voltage comparators of the LM139, 239, 339 and CA139, 239 and 339 series can excite two or more TTL ports. The 10k resistor serves as a load for the comparator and at the same time, it polarizes the TTL inputs. Note that the comparator is powered with the same 5 V as the digital TTL system.
| Clique na imagem para ampliar |
