An optocoupler also called photocoupler or optoisolator, is an electronic device used to transmit an electrical signal between isolated circuits by separate grounds for providing an isolated galvanic wall between them. So, an optocoupler is appropriate for some circuits that need to be separated from each other for security or reliability reasons. Optocouplers are very helpful in removing noise from signals, avoiding distractions from voltage surges, and also separate low-voltage-based devices from higher-voltage circuits. The best examples of optocoupler ICs are; IC PC817, 4NXX series ICs, FOD3180, IC 4N35, etc. This article discusses an overview of the FOD3180 optocoupler, it’s working, and its applications.
What is FOD3180 Optocoupler?
The FOD3180 is a high-speed MOSFET gate driver optocoupler that includes three parts like AlGaAs Infrared emitting diode, o/p power transistors & a CMOS detector that works by detecting the IR light. This optocoupler was introduced by Fairchild Semiconductor to separate or isolate two circuits. These optocouplers are used for driving high-frequency power MOSFETs within PDPs (Plasma Display Panels), high-performance based DC to DC converters. & motor-controlled inverter applications.
The output current provided by the FOD3180 optocoupler is 2Amps & this optocoupler is available in two different packages with 8-pins. This optocoupler provides 5000 VRMS for secure electrical isolation & transmission of electric signals. This IC is included with under-voltage protection to keep away from common pulses & maintain any of the binary pin conditions.
The FOD3180 optocoupler works by using light to two isolate two circuits indirectly. The operational voltage range of this optocoupler ranges from 10V -20V operational voltage range generates 8mA of output current so that it is suitable to drive medium-level loads.
The pin configuration of the FOD3180 Optocoupler is shown below. This optocoupler includes 8 pins where each pin and its function are discussed below.
- Pin1 (NC): It is a not connected pin.
- Pin2 (Anode): It is an anode pin of an IR LED.
- Pin3 (Cathode): It is a cathode pin of an IR LED.
- Pin4 (NC): It is a not connected pin.
- Pin5 (VEE): It is a GND reference potential pin.
- Pin6 (Output): It is an o/p pin of an optocoupler.
- Pin7 (Output): It is an o/p pin of an optocoupler.
- Pin8 (VCC): It is a +ve power supply pin.
Features & Specifications:
The features & specifications of the FOD3180 Optocoupler include the following.
- Its operating voltage ranges from 10V to 20V.
- Its rise time & fall time is 75 ns & 55 ns.
- Its operating temperature ranges from -400oC to 1000 degree Centigrade.
- Its isolation voltage minimum is 5000.
- The input voltage in reverse is 5V.
- Its average i/p current is 25 mA.
- Peak o/p voltage is 0 to VCC.
- The high peak o/p current is 2.5 Amp.
- Its forward current is 10 mA.
- The low peak o/p current is 2.5 Amp.
- Its reverse current is 10 uA.
- Propagation delay with high speed is 200nsec.
- Its switching speed maximum is 250 kHz.
- Pulse width distortion typically is 30nsec.
- Its clearance distance minimum is 7.0mm.
- Its creepage distance minimum is 7.0mm.
- Its total power is 295 mWatts.
- Its o/p power is 250 mWatts.
- It is available in an 8-lead DIP package or an 8-lead SMD package.
Alternative & Equivalent FOD3180 Optocouplers
An alternative FOD3180 opto-couplers are; MOC3021, MOC3041, 6N137, 4N25 & MCT2E whereas equivalent FOD3180 opto-coupler is 6N133.
FOD3180 Optocoupler Circuit Diagram
The FOD3180 MOSFET gate driver optocoupler diagram’s circuit diagram is shown below. The required components to make this circuit mainly include a pulse generator, 100 ohms resistors, FOD3180 optocoupler, 0.33 uF, 0. 1 uF, 22 uF capacitors & 8.5 ohms resistor. Connect the circuit as per the below circuit shown.
This circuit takes in an AC input & gives two AC/DC outputs that are isolated electrically. The pulse generator in the above circuit diagram is connected to the IR LED with two 100 ohms resistors, generating rectangular digital signals. The resistors within the circuit protect the infrared LED & provide control for the switching of the device.
The IR radiation which is generated is proportional to the current. The optocoupler notices it using the embedded CMOS detector. The pins like 5 & 8 at the output side are connected simply to a 5 volts power supply. The VCC pin is directly connected to a bypass capacitor for eliminating the AC noises so that a clean digital output signal is generated.
The power MOSFET output from pin-7 is given to a limiting resistor to adjust and keep away from the additional current. This resistor is connected to a load capacitor (0.33 uF) which signifies the capacitance from the gate to the source of a MOSFET transistor. Here, the FOD3180 optocoupler simply works by translating the infrared radiation by CMOS detector & supplies these high-frequencies based signals to the o/p power transistor, and separates the input & output circuitry.
Advantages & Disadvantages
The advantages of the FOD3180 Optocoupler include the following.
- FOD3180 Optocouplers provide high switching speed, high-frequency response & low output current within a tiny insulated box.
- It provides 5000 Vrms isolation voltage for secure electrical isolation & transmission of the electric signal.
- This optocoupler has inbuilt under-voltage protection that avoids common pulses/
- These types of optocouplers provide best-in-class CMR (common mode rejection) to make the application more resistant to noise.
The disadvantages of the FOD3180 Optocoupler include the following.
- The optocoupler failure can be caused by the LED current leakage as well as the change within the breakdown voltage.
- Optocoupler operation requires an exterior biasing voltage.
- It has a poor higher frequency response.
- It has limited bandwidth.
- It doesn’t handle high currents.
- Optocouplers are not appropriate for long-distance signal transmission.
- It doesn’t perform well in high temperatures.
FOD3180 Optocoupler Applications
The applications of the FOD3180 Optocoupler include the following.
- FOD3180 optocoupler is used in various circuits to remove noise, motor control, isolate two high-frequency circuits, and DC to DC conversions & mainly to drive power MOSFETs within in plasma display panels.
- High AC/DC Switching Circuits.
- Signal isolator circuits.
- Analog current detection.
- Power control.
- Plasma display panel.
- High-performance SMPS.
- High-performance UPS.
Please refer to this link for FOD3180 Optocoupler Datasheet.
Thus, this is an overview of the FOD3180 Optocoupler, pinout, its features, specifications, circuit working, advantages, disadvantages, and applications. This is a high-speed and 2Amps output current MOSFET gate drive optocoupler used mainly for isolating two circuits. Here is a question for you, what is an isolator?