TL431/TL432

ADJUSTABLE PRECISION SHUNT REGULATOR

TL431/432

Document number: DS35050 Rev. 2 - 2

3 of 14

www.diodes.com

September 2010

© Diodes Incorporated

Symbol

Parameter

Test Conditions

Min

Typ.

Max

Unit

Reference voltage

TL431A

2.470

2.495

2.520

V

TL431B

2.482

2.495

2.507

V

Deviation of reference voltage over

full temperature range (Note 5)

6

16

mV

14

34

mV

14

34

mV

Ratio of the change in reference

voltage to the change in cathode

voltage

-1.4

-2.7

mV/V

-1

-2

mV/V

Reference input current

1

4

μA

range (Note 5)

10K

Ω, R2 = ∞

0.8

1.2

μA

0.8

2.5

μA

0.8

2.5

μA

Minimum cathode current for

regulation

0.4

0.7

mA

Off-state current

0.05

0.5

μA

|Z

0.2

0.5

Ω

Thermal Resistance Junction to

Ambient

SOT23

380

SOT25

250

Notes:

The average temperature coefficient of the reference input voltage

αV

Where:

T2 – T1 = full temperature change.

positive or negative.

When the device is programmed with two external resistors R1 and R2, the dynamic output

impedance of the overall circuit, is defined as:

=

T2 – T1

αV

REF

V

DEV

V

X 10

6

ppm/ºC

=

T2 – T1

αV

REF

V

DEV

V

X 10

6

ppm/ºC

Vmax

Vmin

T1

T2

V

Temperature

Vmax

Vmin

T1

T2

V

Temperature

=

Z

KA

ΔV

KA

ΔI

KA

=

Z

KA

ΔV

KA

ΔI

KA

=

Z’

ΔV

ΔI

Z

KA

1 +

R1

R2

≈

=

Z’

ΔV

ΔI

=

Z’

ΔV

ΔI

Z

KA

1 +

R1

R2

Z

KA

1 +

R1

R2

≈