TL431 Datasheet, PDF (3/4 Pages) Motorola, Inc – PROGRAMMABLE PRECISION REFERENCES

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TL431
Note: 1. The deviation parameters V_REF(dev) and I_REF(dev) are defined as the differences between the maximum and minimum
values obtained over the rated temperature range.
V_REF(dev) = V_REF(max) - V_REF(min)
The equivalent full-range temperature coefficient of the reference input voltage, αV_REF is defined as:
( ) ^{V REF(dev)}
× 10 ⁶
) ppm
=
V REF@ ° C
( αVREF
°C
∆ Ta
where ∆Ta is the rated operating free-air temperature range of the device.
αV_REF can be positive or negative depending on whether minimum
V_REF or maximum V_REF respectively, occurs at the lower temperature.
2. The dynamic impedance is defined as:
∆ VKA
ZK A =
∆ IK
When the device is operated with two external resistors (see Figure 2), the total dynamic impedance of the circuit is
given by:
∆V
R1
Z' =
= ZK A (1+ )
∆I
R2
TEST CIRCUITS
Fig.1. Test Circuit for V_KA = V_REF
Fig.2. Test Circuit for V_KA ≥ V_REF
Fig.3. Test Circuit for I_off
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