An open collector output refers to an output that is connected to the collector of a transistor. Basically, just think of a transistor. A BJT transistor has a base, a collector, and an emitter. By open collector, we mean a collector that is unattached to anything..
Also, what is an open collector relay?
Introduction. An Open Collector Digital Output behaves similarly to a Solid State Relay, by toggling the state of the output, you can switch a circuit on and off. This type of output does not supply power to the load like an ordinary digital output, it simply switches a powered circuit to ground.
Similarly, what is the difference between open collector and tri state output? A Tri-State Output, when asserted, can actively source or sink current as directed by logic input. Open Collector Output cannot source current but can only sink, thus when asserted is a logic low.
In this manner, is open collector sinking or sourcing?
8 Answers. This configuration is called common collector or emitter follower. Now the NPN is sourcing, and the PNP is sinking. So, sourcing or sinking doesn't really have much to do with the type of transistor, but rather what it's doing.
What does it mean for a driver to be open drain?
Both SCL and SDA lines are "open drain" drivers. What this means is that the chip can drive its output low, but it cannot drive it high. For the line to be able to go high you must provide pull-up resistors to the 5v supply.
Related Question Answers
How does an open collector work?
An open collector output refers to an output that is connected to the collector of a transistor. Basically, just think of a transistor. A BJT transistor has a base, a collector, and an emitter. In order for an NPN transistor to work, the base and the collector both need sufficient power.How do transistors work?
A transistor is a miniature electronic component that can do two different jobs. It can work either as an amplifier or a switch: A tiny electric current flowing through one part of a transistor can make a much bigger current flow through another part of it. In other words, the small current switches on the larger one.How do open drains work?
An open collector/open drain is a common type of output found on many integrated circuits (IC). Instead of outputting a signal of a specific voltage or current, the output signal is applied to the base of an internal NPN transistor whose collector is externalized (open) on a pin of the IC.What is the use of pull up resistor?
Pull-up Resistors. Pull-up resistors are simple fixed value resistors, that are connected between the voltage supply and the particular pin. These resistors are used in digital logic circuits to ensure a logic level at a pin, which results in state wherein the input/output voltage is nonexistence driving signal.Why is a pull up resistor needed for an open collector gate?
A pull-up resistor connects unused input pins (AND and NAND gates) to the dc supply voltage, (Vcc) to keep the given input HIGH. Some open-collector gates, such as the 74LS06 are capable of driving larger loads because their outputs can be connected to supplies of up to 30 volts via an external pull-up resistor.What is open drain output?
Definition. An open-drain or open-collector output pin is driven by a single transistor, which pulls the pin to only one voltage (generally, to ground). When the output device is off, the pin is left floating (open, or hi-z).What is totem pole in TTL?
Totem Pole Output: Totem Pole means addition of an active pull up circuit in the output of the Gate which results in reduction of propagation delay. Logic operation is same as the open collector output. Use of transistors Q4 and diode is to provide quick charging and discharging of parasitic capacitance across Q3.What is open drain in CMOS technology?
cmos means complementry MOSFET, and open drain means the output is drawn from drain terminal of mosfet. consider a mosfet withot VDD.here the drain is floating. this is called open drain.What is sinking input?
Sinking and Sourcing are terms used to define the control of direct current flow in a load. A sinking digital I/O (input/output) provides a grounded connection to the load, whereas a sourcing digital I/O provides a voltage source to the load.Is NPN sinking or sourcing?
PNP sensors are sometimes called “sourcing sensors” because they source positive power to the output. NPN sensors are sometime called “sinking sensors” because they sink ground to the output. The term “load” identifies the device the sensor powers. The load could be a lamp, pneumatic valve, relay or PLC input.What is sinking output?
Sinking VS Sourcing Digital Outputs A sinking digital (input/output) provides a grounded connection to the load, whereas a sourcing digital(input/output) provides a voltage source to the load. In this circuit, the load is pulled up to receive voltage because the sourcing digital input has been provided.What is current sourcing?
Current sourcing and sinking refers to the way that an external load is connected to a circuit, system, microcontroller or other electronic device.What is sourcing & sinking in PLC?
The Sinking and Sourcing are the input/output module cards used in PLCs. A sinking digital I/O (input/output) provides a grounded connection to the load, whereas a sourcing digital I/O provides a voltage source to the load.What is NPN transistor?
NPN Transistor. Definition: The transistor in which one p-type material is placed between two n-type materials is known as NPN transistor. The NPN transistor amplifies the weak signal enter into the base and produces strong amplify signals at the collector end.What is meant by source and sink?
A source or a sink is defined by which compartment is viewable by the observer. A source is: A flow of positive charges from the "invisible" to the "visible" compartment (i.e. toward the eye), or… A flow of negative charges from the "visible" to the "invisible" (away from the eye).What is difference between NPN and PNP?
The main difference between the NPN and PNP transistor is, an NPN transistor turns on when the current flows through the base of the transistor. In this type of transistor, the current flows from the collector (C) to the emitter (E). A PNP transistor turns ON, when there is no current at the base of the transistor.How do PNP proximity sensors work?
When a sensor with a PNP output is activated, it puts into contact the signal wire with the power supply wire. The voltage on the signal wire therefore changes to the value of the power supply voltage. It has the advantage of being very simple, but you can't really choose the signal output voltage.What is an open collector input?
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. The emitter of the transistor is connected internally to the ground pin.What does tristate mean?
"Tristate" means a state of high impedance. A pin can either pull to 0 V (sinking current, generally), pull to 5 V (sourcing current, generally), or become high impedance, like an input. When it's an input, it's "tristated," allowing the external chip to control its logic level. 
