Sage-Tips

What is the advantage of using an open-collector output?

The advantage of open-collector outputs, or open-drain outputs is that the load to be switched or controlled can be connected to a voltage supply which is independant, and/or different from the supply voltage used by the controlling circuit, and that they can “sink” or “source” an externally-supplied voltage depending …

What does an open collector do?

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 open collector sensor?

The open collector works with DC power and basically toggles the current flow from the output signal wire to ground. When the internal sensing signal is negative (liquid absent), it prevents current from flowing to the Emitter: Some Gems flow sensors also have open collector outputs.

How do collector outputs work open?

In order for an open collector output device to work, the open collector has to receive sufficient power. In order to understand this, you have to understand NPN transistors. In order for an NPN transistor to work, the base and the collector both need sufficient power. The base turns the transistor on.

When open collector gates are used is there any limitation on the value of pull up resistor?

If you tie it to 6 volts then it will go up to 6 volts. The resistor just limits the current so when the gate is on, it will not burn out. A high value like 100K is generally ok as long as whatever the gate feeds does not need much current.

What does the collector do on a transistor?

The collector-base junction is always in reverse bias. Its main function is to remove the majority charges from its junction with the base. The collector section of the transistor is moderately doped, but larger in size so that it can collect most of the charge carrier supplied by the emitter.

What is open drain and open collector?

An “open collector” is functionally the same as an “open drain”. An “open collector” refers to a current sink on a BJT transistor output, while an “open drain” refers to a current sink on a FET output.

What is open collector pull up resistor?

Open collector outputs require a pull-up resistor (R in the image above) for the output to be able to properly “output high”. The pull-up resistor is connected between the output pin and the output voltage (Vcc in the image above) that is desired for a high state.

What is open collector TTL?

3.1 Open Collector output: 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 the role of collector in BJT?

The role of the collector region is to collect or attract current carriers injected inot the base region of the transistor. In a bipolar junction transistor, current flows from the emitter to the collector and then out from the collector. Therefore, the collector attracts the majority of the charge carrier.

What is an IC with an open collector output?

In what follows, we’ll work with the SN7407N, which is one of the most basic ICs with open-collector outputs. We’ll discuss what it means to have “open collector” outputs, and show some of the different ways that they are used.

What is an open collector in a bipolar transistor?

The buffer input goes into a logical NOT gate. The output of that NOT gate goes to the base of an NPN bipolar transistor. The emitter of the transistor is connected to ground and the collector of the transistor is connected to the output. This is the “open collector.”.

How can I use the sn7407n open collector outputs?

For the SN7407N, the output can go as high as 30 V, so you can also use it to shift higher as well. Another way that you can use open collector outputs is as a compact substitute for a set of external, discrete transistors. Suppose that you wanted to drive six sets of three white LEDs each, controlled by six outputs from your microcontroller.