Diodes AP431A User Manual

E

Description

AP431/AP431A

ADJUSTABLE PRECISION SHUNT REGULATOR

Pin Assignments

The AP431 and AP431A are 3-terminal adjustable precision shunt
regulators with guaranteed temperature stability over the applicable
extended commercial temperature range. The output voltage may be
set at any level greater than 2.495V (V

) up to 36V merely by

REF

selecting two external resistors that act as a voltage divider network.
These devices have a typical output impedance of 0.2. Active output
circuitry provides very sharp turn-on characteristics, making these
devices excellent improved replacements for Zener diodes in many
applications.

CATHODE

(1) SOT25 (2) SO-8

NC

(Top View)

18

2

3
4

NC

NC

(Top View)

1

2

3

5ANOD

4REF

CATHODE

ANODE
ANODE

(3) SC59 (4) SC59R

7

6
5

The precise (+/-) 1% reference voltage tolerance of the
AP431/AP431A make it possible in many applications to avoid the
use of a variable resistor, consequently saving cost and eliminating
drift and reliability problems associated with it.

Features

 Precision Reference Voltage

(5) SOT23 (6) SOT23R

(Top View)

 AP431: 2.495V ± 1%

REF

1

ANODE

3

2

 AP431A: 2.495V ± 0.5%
 Sink Current Capability: 200mA
 Minimum Cathode Current for Regulation: 300A
 Equivalent Full-Range Temp Coefficient: 30ppm/°C

CATHODE

 Fast Turn-On Response
 Low Dynamic Output Impedance: 0.2
 Programmable Output Voltage to 36V
 Low Output Noise
 Lead Free Packages: SOT25, SC59, SC59R, SOT89 SO-8 and

TO92

 Totally Lead-Free; RoHS Compliant (Notes 1 & 2)

 SOT23, SOT23R, SOT25, SC59, SC59R, SO-8, SOT89, TO92:

Available in “Green” Molding Compound (No Br, Sb). See
“Ordering Information”

 Halogen and Antimony Free. “Green” Device (Note 3)

(7) SOT89 (8) TO92

(Top View)

2

1

Anode Cathode

REF

3

(Top View)

+
+
+

3 Cathode

2 Anode

1 REF

Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.

2. See http://www.diodes.com for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free.

3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl)
and <1000ppm antimony compounds.

REF
ANODE

ANODE

NC

AP431/AP431A

Document number: DS31002 Rev. 21 - 2

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A

Typical Applications Circuit



V

IN

AP431/AP431A

V

OUT

Symbol

+

C

IN

R1

+

C

OUT

A431P

R2

V = (1 + R1/ R2) V

OUT REF

Precision Regulator

Cathode (C)

REF (R)

Functional Block Diagram

REF (R)

Anode (A)

+

-

V

REF

node (A)

Cathode (C)

AP431/AP431A

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AP431/AP431A

Absolute Maximum Ratings (@T

Parameter Rating Unit

Cathode Voltage +36 V
Continuous Cathode Current -10 to +250 mA
Reference Input Current 10 mA
Operating Temperature -20 to +85 °C
Storage Temperature -65 to +150 °C

Power Dissipation (Notes 4, 5)

Notes: 4. TJ, max = +150°C.

5. Ratings apply to ambient temperature at +25°C.

Electrical Characteristics (@T

Symbol Parameter Conditions Min Typ Max Units

= +25°C, unless otherwise specified.)

A

SOT23(R) 400 mW
SOT25 550 mW
SC59(R) 400 mW
SO-8 600 mW
SOT89 800 mW
TO92 780 mW

= +25°C, VDD = 3V; unless otherwise specified.)

A

V

REF

V

DEV

V

REF

V

KA

I

REF

I

REF

I

KA(MIN)

I

KA(OFF)

|ZKA|

Reference voltage

Deviation of reference input voltage over
temperature (Note 5)

Ratio of the change in reference voltage to
the change in cathode voltage

Refernce input current
Deviation of reference input current over

temperature
Minimum cathode current for regulation

Off-state current

Dynamic output impedance (Note 7)

V

= V

KA

I

KA

V

KA

T

= Full Range (Figure 1)

A

I

KA

,

REF

= 10mA (Figure 1)

= V

, IKA = 10mA

REF

= 10mA (Figure 2)

AP431
AP431A

= V

REF

to 10V

V

KA

VKA = 10V to 36V
R1 = 10K, R2 =  IKA = 10mA (Figure 2)
R1 = 10K, R2 =  I

T

= Full range (Figure 2)

A

VKA = V
VKA = 36V, V
V

KA

I

KA

(Figure 1)

REF

REF

= V

REF VKA

= 0.1mA to 15mA

= 10mA

KA

= 0V (Figure 3)

= V

REF

Frequency  1KHz (Figure 1)

2.470

2.482

2.495

2.520

2.507

V

— 8.0 20.0 mV

— -1.4 -2.0 mV/V
— -1 -2 mV/V
— 1.4 3.5 µA

— 0.4 1.2 µA
— 0.19 0.50 mA

— 0.1 1.0 µA

— 0.2 0.5 

AP431/AP431A

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Electrical Characteristics (cont.) (@T

V

MAX

V

MIN

= +25°C, VDD = 3V; unless otherwise specified.)

A

V = V - V

DEV MAX MIN

AP431/AP431A

Note: 6. Deviation of reference input voltage, V

The average temperature coefficient of the reference input voltage V

V

(

V

REF

Where:
T2 – T1 = full temperature change.

can be positive or negative depending on whether the slope is positive or negative.

V

REF

REF



T1 T2Temperature

, is defined as the maximum variation of the reference over the full temperature range.

DEV

is defined as:

REF

DEV





6

10)



C)(25V

TT

12

……………………..………..…………….. (

ppm

)

C



Note: 7. The dynamic output impedance, RZ, is defined as:

V





KA

IN

KA

I



KA

R1

(1Z

)



R2

IN

Z

KA

When the device is programmed with two external resistors R1 and R2 (see Figure 2.), the dynamic output impedance of the overall
circuit, is defined as:

v



'

Z

 ≈

Test Conditions

KA



i



Input

V

KA

I

KA

V

REF

Figure. 1 Test Circuit for V = V

KA REF

AP431/AP431A

Document number: DS31002 Rev. 21 - 2

R1

I

REF

V

R2

Note: V = V (1 + R 1/R2) + I xR1

KA REF REF

Figure. 2 T est Circuit for V > V

REF

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I

KA

V

KA

KA REF

V

KA

I

Z(OFF)

Figure. 3 Test Circuit for Off-State C ur r ent

© Diodes Incorporated

June 2013

O

CAT

E CURRENT

A

R

R

R

R

C

A

G

R

F

RENC

O

A

G

Typical Performace Characteristics

100

DE CURRENT(mA)

0

V = V

KA REF



T = 25C

A

AP431/AP431A

V = V

KA REF

600

T = 25C



A



400

I

KA(MIN)

200

)
(m

HOD

CATH

-100

250

2495

2490

2485

2480

CATHODE VOL TAGE (V)

0.5 1.5 2.5-0.5-1

Cathode Cur r ent vs. Cathod e Voltage

06080-20-40

20 40

FREE-AIR TEMPERATURE (C)

Referenc e Voltage vs. Free-A ir Temperature

0

CATHODE CURRENT( A)

0

-200

0.5 1 1.5 2 2.50-0.5-1

CATHODE VOLTAGE (V)

Cathode Current ( A) vs. Cath ode Voltage



2

R1 = 10k
I = 10mA



KA

1.8

ENT( A)

1.6

1.4

ENCE INPUT CU

1.2

EFE

1

25 50 75 100 1250-25-50

FREE -A IR T EM PE R ATURE (V)

Reverence Input Current vs. Free Temperature

-2

E (mV)

I = 10mA

KA

T = 25C



LT

A

-4

E V

-6

E
E

-8

E in
N

-10

H

-12
10 25 3050

15 20

CATHODE VOLTAGE (V)

Change in Reference Voltage vs. Cathode Voltage

AP431/AP431A

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O

CAT

E CURRENT

A

R

R

R

R

C

A

G

R

F

RENC

O

A

G

Typical Performance Characteristics (cont.)

100

DE CURRENT(mA)

0

V = V

KA REF



T = 25C

A

AP431/AP431A

V = V

KA REF

600

T = 25C



A



400

I

KA(MIN)

200

)
(m

HOD

CATH

-100

250

2495

2490

2485

2480

CATHODE VOL TAGE (V)

0.5 1.5 2.5-0.5-1

Cathode Cur r ent vs. Cathod e Voltage

06080-20-40

20 40

FREE-AIR TEMPERATURE (C)

Referenc e Voltage vs. Free-A ir Temperature

0

CATHODE CURRENT( A)

0

-200

0.5 1 1.5 2 2.50-0.5-1

CATHODE VOLTAGE (V)

Cathode Current ( A) vs. Cath ode Voltage



2

R1 = 10k
I = 10mA



KA

1.8

ENT( A)

1.6

1.4

ENCE INPUT CU

1.2

EFE

1

25 50 75 100 1250-25-50

FREE -A IR TE M PE R ATURE (V)

Reverence Input Current vs. Free Temperatur e

-2

E (mV)

I = 10mA

KA

T = 25C



LT

A

-4

E V

-6

E
E

-8

E in
N

-10

H

-12
10 25 3050

15 20

CATHODE VOLTAGE (V)

Change in Reference Voltage vs. Cathode Voltage

AP431/AP431A

Document number: DS31002 Rev. 21 - 2

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