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What are some tips for modeling optocouplers for Pspice?, C( m5 ]: C# A) J) d
Though Model Editor does not provide a template for either an optocoupler or for a phototransistor, it can beused create components of these models. For example,you can use Model Editor to model the electricalcharacteristics of the input LED of an optocoupler.- N z0 B5 S' i3 j
In the case of the optocoupler，you need to create a model for a LED input，and also for a single BJTphototransistor output optocoupler." b+ l: x3 y- }4 k( q
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To model LED input, fit the forward current vs. voltage curve of the LED, and the LED capacitance curve toa PSpice diode. These curves are available in datasheets.
- J6 e3 g. L! j# O2.CTR curve fit
5 q: I4 n. ~7 a2 o) B% ^/ ^Use Mathcad or Excel to fit the CTR curve to a polynomial. A polynomial which may work is of the formA*exp(B+Cx).2 r5 x- K, ~$ N
In the sample model shown below, the Gpcg source models the CTR curve. In this case, two regions were fitseparately, the region If<=10mA and the region If>10mA, where If is the LED forward current. The outputcurrent of the Gpcg source is the phototransistor collector current.
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发表于 2021-3-16 10:09
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