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VKA (V)

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IKA(min)

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KA

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TL431LI

TL432LI

SLVSDQ6A – JULY 2018 – REVISED NOVEMBER 2018

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Product Folder Links: TL431LI TL432LI

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Copyright © 2018, Texas Instruments Incorporated

8.2 Dynamic Impedance

The dynamic impedance is defined as:

. When the device is operating with two external resistors

(see Figure 15), the total dynamic impedance of the circuit is given by:

which is approximately equal to

.

The VKA of the TL431LI can be affected by the dynamic impedance. The TL431LI test current Itest for VKA is

specified on the Eletrical Characteristics . Any deviation from Itest can cause deviation on the output VKA.

Figure 17 shows the effect of the dynamic impedance on the VKA.

Figure 17. Dynamic Impedance