Absolute Maximum Ratings (Note 2)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Storage Temperature Range

−65˚C to +150˚C

Operating Temperature Range

Industrial (LM431xI)

−40˚C to +85˚C

Commercial (LM431xC)

0˚C to +70˚C

Soldering Information

Infrared or Convection (20 sec.)

235˚C

Wave Soldering (10 sec.)

260˚C (lead temp.)

Cathode Voltage

37V

Continuous Cathode Current

−10 mA to +150

mA

Reference Voltage

−0.5V

Reference Input Current

10 mA

Internal Power Dissipation (Notes 3,

4)

TO-92 Package

SO-8 Package

SOT-23 Package

0.78W

0.81W

0.28W

micro SMD Package

0.30W

Operating Conditions

Min

Max

Cathode Voltage

V

REF

37V

Cathode Current

1.0 mA

100 mA

LM431

Electrical Characteristics

T

Symbol

Parameter

Conditions

Min

Typ

Max

Units

V

REF

Reference Voltage

V

2.440

2.495

2.550

V

LM431A (Figure 1 )

V

2.470

2.495

2.520

V

LM431B (Figure 1 )

V

2.485

2.500

2.510

V

LM431C (Figure 1 )

V

DEV

Deviation of Reference Input Voltage Over

V

8.0

17

mV

Temperature (Note 5)

T

Ratio of the Change in Reference Voltage

I

V

−1.4

−2.7

mV/V

to the Change in Cathode Voltage

(Figure 2 )V

−1.0

−2.0

I

REF

Reference Input Current

R

Ω,R

2.0

4.0

µA

I

∝I

REF

Deviation of Reference Input Current over

R

Ω,R

Temperature

I

0.4

1.2

µA

T

I

Z(MIN)

Minimum Cathode Current for Regulation

V

0.4

1.0

mA

I

Z(OFF)

Off-State Current

V

TARGET FOR fi* )

0.3

1.0

µA

r

Z

Dynamic Output Impedance (Note 6)

V

0.75

Ω

Frequency=0Hz (Figure 1 )

V

0.50

Ω

Frequency=0Hz (Figure 1 )

Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device

beyond its rated operating conditions.

Note 4: Ratings apply to ambient temperature at 25˚C. Above this temperature, derate the TO-92 at 6.2 mW/˚C, the SO-8 at 6.5 mW/˚C, the SOT-23 at 2.2 mW/˚C

and the micro SMD at 3mW/˚C.

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