Open Collector Vs Open Drain

April 05, 2024 Post a Comment

Open collector vs open drain

Glossary Term: Open-drain Open-drain refers to such a circuit implemented in FET technologies because the transistor's drain terminal is connected to the output; open-collector means a bipolar transistor's collector is performing the function.

What is meant by open collector?

An open collector is a common type of output found on many integrated circuits (IC), which behaves like a switch that is either connected to ground or disconnected.

How open collector or open drain is useful in IIC?

Open drain allows there to be multiple masters on the same bus. If two masters try to transmit at the same time with push-pull drivers, they can damage each other, and even if they don't it's hard to tell which master will win.

What is the meaning of open drain?

Open Drain means an open channel used to transport water, groundwater, and surface water runoff or drainage water from any source.

Why I2C is open drain?

The Open Drain. A defining characteristic of I2C is that every device on the bus must connect to both the clock signal (abbreviated SCL) and the data signal (abbreviated SDA) via open-drain (or open-collector) output drivers.

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.

Why do we use open collector?

Rather than output a signal we often want to provide a current sink. 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.

What is open drain in GPIO?

The DS2413 outputs are "Open Drain". What that means is that the output is the "Drain" of an N-channel FET: Internally, the "Source" of the FET is connected to Ground. But the Drain is left open. When switched on, the FET provides a path for current to flow from the output pin to ground.

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.

Is open-collector NPN or PNP?

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.

What is open-collector in I2C?

I2C uses an open-drain/open-collector with an input buffer on the same line, which allows a single data line to be used for bidirectional data flow. 1.1. Open-Drain for Bidirectional Communication.

Is open drain high impedance?

The open-drain structure provides a high impedance at the output pin when powered off. This is especially important in partial-power-off applications where the device's low Ioff leakage-current specification is significant.

What is open collector output in VFD?

The Open-Collector Output is a transistor circuit configuration used in a wide variety of electronic designs includ- ing many integrated circuits (ICs). Three parts make up a transistor: the emitter, the base and the collector.

What is an open drain comparator?

On the basis of outputs, comparators can also be classified as open-drain or push–pull. Comparators with an open-drain output stage use an external pull-up resistor to a positive supply that defines the logic high level. Open-drain comparators are more suitable for mixed-voltage system design.

Why are comparators open-collector?

Open Collector Output Transistors Because the output transistor of the comparator has an open collector the supply and load voltages do not have to be the same. This means that the comparator could use a 12 Volt power supply while the load could be a 24 Volt relay or 5 Volt LED circuit.

What is SCL and SDA pins?

The I2C protocol involves using two lines to send and receive data: a serial clock pin (SCL) that the Arduino Controller board pulses at a regular interval, and a serial data pin (SDA) over which data is sent between the two devices.

Does I2C need pullup resistors?

The I2C bus must have pull-up resistors, one on the SDA line and one on the SCL line. They're typically 4.7K or 10K ohm, but should be in the range of 2K to 10K.

What is maximum I2C speed?

The I2C (inter-IC) bus is a 2-wire, multi-drop, digital communications link for ICs that has become the defacto standard for many embedded applications. Serial, 8-bit, bidirectional data transfer can occur at speeds up to 3.4Mbps, though 400kHz is usually sufficient.

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 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.