Open Collector Output - Is Open Drain Input Or Output?

In both of the scenarios, the point to be noted is that the open drain/collector is a part of the output transistor which is directly connected out to a pin that is on the external side of the integrated circuit.

How does push-pull output work?

A Push-Pull output is an output that allows you to connect either a sinking or sourcing circuit. (see What is a Sinking or Sourcing input?) This type of an output allows you to sink more current than a Totem Pole output and follow the input voltage.

What is collector drain?

A collector sewer is used to convey waste from smaller tributaries toward the waste treatment plant. It is part of a multi-tiered wastewater collection system in a city or metropolitan area. The terms for each tier may vary in different municipalities, regions or countries.

What is a totem pole output?

Totempole output has an output circuit with two transistors combined between VCC and GND. The high or low level is determined without setting pull-up resistance to the output. Totempole output can both sink and source. For open collector output, a transistor's collector is externalized on the output.

Why I2C lines are open drain?

I2C is multi-master and multi-slave protocol. If the lines are not open drain then there may chance that one slave pulling the device low and other slave is trying to pull the same line high. This situation is called as the bus contention.

What is open collector signal?

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.

Is open collector a dry contact?

A "dry contact input" generally expects that its two contacts will be shorted to each other to activate it -- and NOT shorted to anything else. An "open collector output" is one that is open-circuit when inactive, and shorted to ground when active.

What is N channel open drain output?

When the output device is off, the pin is left floating (open, or hi-z). A common example is an n-channel transistor which pulls the signal to ground when the transistor is on or leaves it open when the transistor is off.

Why open drain is used?

An open-drain is commonly found in many integrated circuits. This helps multiple devices to connect with the usage of single wire which is in a mode of pull-down operation.

Does open collector need a 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 push pull vs open drain?

While a push-pull sensor has two MOSFETs that alternately conduct to provide high or low output signals, an open drain sensor has only one MOSFET. When a magnetic field turns the open-drain sensor on, the MOSFET conducts, allowing current to sink through the pull-up resistor to ground.

What is open emitter?

open-emitter output: An open-circuit output whose internal connection is to the emitter of a bipolar transistor. NOTE — For graphic symbols, see “source driver” (for npn) or “sink driver” (for pnp). open-source output: An open-circuit output whose internal connection is to the source of a field-effect transistor.

What is the difference between 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 drain buffer?

Buffer with open-drain output. The 74LVC1G07 is a single buffer with open-drain output. Inputs can be driven from either 3.3 V or 5 V devices. This feature allows the use of these devices as translators in mixed 3.3 V and 5 V environments.

What is a dry contact output?

a dry contact is where a devices output closes a pair of contacts with no connection to any internal circuit or power - eg a PIR sensor can be dry contact with its power supply of 240v or low voltage, but we connect 24v to one of the dry contacts and its switched to the other contact when it detects movement.

What is the output of open collector?

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.

What is a 3 state output?

A three-state, or Tri-State™, output has three electrical states: One, zero, and "Hi-Z," or "open." The hi-Z state is a high-impedance state in which the output is disconnected, leaving the signal open, to be driven by another device (or to be pulled up or down by a resistor provided to prevent an undefined state).

Why is it called open collector?

The term “open collector” refers to a current sink on a transistor output. If an NPN transistor is left unconnected, or open but connected to an external pin, it's an open collector.

What is an open collector input and why is it used on sensors?

The open-collector output of a power supply is a method of control circuitry used to output the state (status) and other information of the power supply. The output of a power supply is controlled by an open collector to turn it on and off externally.

What is a dry contact input?

A dry contact, also called a volt-free contact, is a relay contact that does not supply voltage. The relay energizes or de-energizes when a change to its input has occurred. In other words, a dry contact simply detects whether or not an input switch is open or closed.