Integrated-Circuit Logic Families - Technical MCQs

Q1:

Refer to the figure given below. What type of device is shown and what input levels are required to turn the LED off?

A The device is an open-collector AND gate and requires both inputs to be HIGH in order to turn the LED off.

B The device is a Schottky AND gate and requires only one low input to turn the LED off.

C The device is an open-collector AND gate and requires only one low input to turn the LED off.

D The device is a Schottky open-collector AND gate and requires a low on both inputs to turn the LED off.

ANS:A - The device is an open-collector AND gate and requires both inputs to be HIGH in order to turn the LED off.

Does that say -5V at the top? if so, it probably doesn't matter what the input states are. The LED will never light.