The main work of optocoupler in the circuit is to isolate and convert photoelectricity, and there are many applications, so optocouplers also have many types, which can be divided into different types according to different classification methods, and the classification methods of general optocouplers are:
1. According to the optical path
It can be divided into an outer optical path photocoupler (also known as a photointerrupted detector) and an internal optical path photocoupler. External optical path photocouplers are further divided into transmittance and reflection photocouplers.
2. According to the output form
(1) Photosensitive device output type, including photodiode output type, phototransistor output type, photocell output type, photocyristor output type, etc.
(2) NPN transistor output type, including AC input type, DC input type, complementary output type, etc.
(3) Darlington transistor output type, including AC input type and DC input type.
(4) Logic gate output type, including gate output type, Schmitt trigger output type, three-state gate output type, etc.
(5) Low conduction output type (output low level millivolt order of magnitude).
(6) Optical switch output type (on-resistance less than 10Ω).
(7) Power output type (IGBT/MOSFET output).
3. According to the packaging form
It can be divided into coaxial type, double in-line type, TO package type, flat package type, SMD package type, and optical fiber transmission type.
4. According to the transmission signal
It can be divided into digital optocoupler (OC gate output type, totem pole output type and three-state gate circuit output type, etc.) and linear optocoupler (can be divided into low drift type, high linearity type, broadband type, single power supply type, dual power supply type, etc.).
5. Divide according to speed
It can be divided into low-speed photocoupler (output type such as phototransistor and photocell) and high-speed photocoupler (photosensitive diode with signal processing circuit or photosensitive integrated circuit output type).
6. According to the channel
It can be divided into single-channel, dual-channel and multi-channel optocouplers.
7. According to the isolation characteristics
It can be divided into ordinary isolation optocoupler (general optical glue potting is less than 5000V, empty sealing is less than 2000V) and high-voltage isolation optocoupler (can be divided into 10kV, 20kV, 30kV, etc.).
8. According to the working voltage
It can be divided into low power supply voltage type optocoupler (generally 5~15V) and high power supply voltage type optocoupler (generally greater than 30V).