What is open collector TTL NAND gate?

In the open collector TTL gate, the output stage does not have the active pull-up transistor i.e. Q3 and the output is taken at the collector of transistor Q4. In order to generate required HIGH and LOW states, an external pull-up resistor is connected to +Vcc from the collector of Q4.

What is open collector gate?

Open-collector devices are commonly used to connect multiple devices to one interrupt request signal or a shared bus such as I²C. This enables one device to drive the bus without interference from the other inactive devices.

What is NAND gate truth table?

The NAND gate is a combination of an AND gate and NOT gate. They are connected in cascade form. It is also called Negated And gate. The NAND gate provides the false or low output only when their outputs is high or true.

What are open collector outputs?

An Open Collector output is an NPN transistor. An NPN transistor allows the sinking of current to common. It can be thought of as a switch that allows the circuit, after the load, to be connected to common. This means that a source is required for the output to work.

How do you use open collector output?

With open collector output, you simply cannot just connect the output device to the pin and then to ground. Open collector does not work that way. It must have positive voltage and then the load and the negative or ground side of the load connects to the output.

Why do we use open-collector?

This is common when controlling power to a circuit. An open-collector output is used to connect one side of the device being controlled to ground. The other side of the device will be connected to power. If you look at the CRICKIT “drive” outputs you will see that this is exactly what they are.

What is NAND gate formula?

The Boolean equation of NAND gate is `Y=bar(A*B)` and it is read as “Y is equal to NOT A and B”. NAND gates are also called universal gates since by using the gates you can realise other basic gates like OR, AND and NOT.

What is NAND gate draw?

In digital electronics, a NAND gate (NOT-AND) is a logic gate which produces an output which is false only if all its inputs are true; thus its output is complement to that of an AND gate. A LOW (0) output results only if all the inputs to the gate are HIGH (1); if any input is LOW (0), a HIGH (1) output results.

What is TTL open-collector output?

TTL gates with open-collector output stages have eliminated R3, Q3 and the diode, Figure 145. The collector of Q4 is connected only to the output Y. In order for open-collector TTL gates to work, an external pull-up resistor must be provided (of the order 10 k ).