How is optocoupler calculated?
The gain of the optocoupler is expressed as a current transfer ratio (CTR), which is the collector current (IC) of the output divided by the forward current (IF) of the input and multiplied by 100 %. There are typically a number of CTR groups (binning) to choose from when selecting an optocoupler.
What should be the ideal input resistance of an optocoupler?
The output current available from a HCT gate to drive the optocoupler input is limited to 4mA, which is quite low for driving an optocoupler. Therefore the output current of the PC817 needs also to be ideally about 4mA, with the forward current (IF) driving the input LED at 4mA (assuming a 100% CTR).
What is PC817?
PC817 IC is an optocoupler that includes a phototransistor and an IR diode. PC817 IC includes an LED & a phototransistor which are connected jointly optically. The signal can be transmitted optically in between an i/p and an o/p side without any physical connection.
What is an opto output?
An optocoupler (also called optoisolator) is a semiconductor device that allows an electrical signal to be transmitted between two isolated circuits. Two parts are used in an optocoupler: an LED that emits infrared light and a photosensitive device that detects light from the LED.
What are optocouplers used for?
Optocouplers can either be used on their own as a switching device, or used with other electronic devices to provide isolation between low and high voltage circuits. You’ll typically find these devices being used for: Microprocessor input/output switching. DC and AC power control.
What does a photocoupler do?
An opto-isolator (also called an optocoupler, photocoupler, or optical isolator) is an electronic component that transfers electrical signals between two isolated circuits by using light. Usually opto-isolators transfer digital (on-off) signals, but some techniques allow them to be used with analog signals.