Diodes AP432A User Manual

AP432/AP432A

ADJUSTABLE PRECISION SHUNT REGULATOR

Description

The AP432 and AP432A are 3-terminal adjustable precision shunt
regulators with guaranteed stable temperature over the applicable
extended commercial temperature range. The output voltage may be
set at any level greater than 1.24V (V
selecting two external resistors that act as a voltage divider network.
These devices have a typical output impedance of 0.2Ω. Active output
circuitry provides very sharp turn-on characteristics, making these
devices excellent improved replacements for Zener diodes in many
applications.

The precise +/- 1% reference voltage tolerance of the
AP432/AP432A 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.

) up to 20V merely by

REF

Features

• Precision Reference Voltage

 AP432 : 1.24V ± 1%
 AP432A : 1.24V ± 0.5%

• Sink Current Capability: 200mA

• Minimum Cathode Current for Regulation: 150μA

• Equivalent Full-Range Temp Coefficient: 30 ppm/°C

• Fast Turn-On Response

• Low Dynamic Output Impedance: 0.2Ω

• Programmable Output Voltage to 20V

• Low Output Noise

• Lead Free packages: SOT25, SC59, SC59R, SOT89-3 and

TO92
 Lead-Free Finish; RoHS Compliant (Notes 1 & 2)

• SOT23, SOT23R, SOT25, SC59, SC59R, SO-8, SOT89 and
TO92: Available in “Green” Molding Compound (No Br, Sb)
 Halogen and Antimony Free. “Green” Device (Note 3)

Notes: 1. EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. All applicable RoHS exemptions applied.

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.

Pin Assignments

(1) SOT25 (2) SO-8

(Top View)

NC

1

NC

2

CATHODE

3

(3) SC59 (4) SC59R

(Top View)

ANODE 1

(5) SOT23 (6) SOT23R

(Top View)

ANODE 1

(7) SOT89-3 (8) TO92

(Top View)

2

1

Anode Cathode

REF

5 ANODE

4REF

3

2 CATHODE

3REF

2CATHOD

3

REF

CATHODE

ANODE
ANODE

ANODE 1

ANODE

NC

(Top View)

(Top View)

1

(Top View)

+
+
+

(Top View)

18

2

3
4

2

3 Cathode
2 Anode

1 REF

Typical Applications Circuit

REF

7

ANODE

ANODE

6
5

NC

3 CATHODE

2REF

CATHODE3

REF

AP432/AP432A

Document number: DS31003 Rev. 18 - 2

+

C

in Cout

AP432

VOUT = (1+R1/R2)VREF

Precision Regulator

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R1

R2

+

OUTVIN

V

September 2012

© Diodes Incorporated

Functional Block Diagram

REF (R)

V

AP432/AP432A

+

-

REF

Cathode (C)

Functional Block Diagram

Absolute Maximum Ratings (@T

Symbol Parameter Rating Unit

VCV Cathode Voltage 20 V

ICC Continuous Cathode Current -10 to +250 mA

I

Reference Input Current 10 mA

REF

TOP Operating Temperature -20 to +85 °C
TST Storage Temperature -65 to +150 °C

PD

Notes: 4. TJ, max = +150°C.

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

Power Dissipation

(Notes 4, 5)

AP432/AP432A

Document number: DS31003 Rev. 18 - 2

Anode (A)

Cathode (C)

REF (R)

Anode (A)

= +25°C, unless otherwise specified.)

A

SOT23(R) 400 mW
SOT25 550 mW
SC59(R) 400 mW
SO-8 600 mW
SOT89-3 800 mW
TO92-3 780 mW

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AP432/AP432A

Electrical Characteristics (@T

Symbol Parameter Test Conditions Min Typ Max Unit

V

Reference voltage

REF

Deviation of reference input voltage over

V

ΔV

ΔV

temperature

REF

(Note 4)

REF

Ratio of the change in reference voltage to

KA

the change in cathode voltage

= +25°C, unless otherwise specified.)

A

V

= V

KA

I

KA

V

KA

,

REF

= 10mA (Figure 1)

= V

, IKA = 10mA,

REF

AP432
AP432A

Ta = Full range (Figure 1)

= 10mA (Figure 2) VKA = 20 ~ V

I

KA

REF

1.227

1.233

1.24

⎯

⎯

-1.4 -2.0 mV/V

1.252

1.246

V

3.0 20 mV

I

Reference input current R1 = 10KΩ,R2 = ∞ IKA= 10mA (Figure 2)

REF

αI

I

KA(MIN)

I

KA(OFF)

|ZKA|

Deviation of reference input current over

REF

temperature

Minimum cathode current for regulation VKA = V

Off-state current VKA = 36V, V

Dynamic output impedance
(Note 5)

R1 = 10KΩ,R2 = ∞ I
T

= Full range (Figure 2)

A

(Figure 1)

REF

REF

V

= V

KA

REF V KA

ΔI

= 0.1mA ~ 15mA

KA

Frequency≤ 1KHz (Figure 1)

= 10mA

KA

= 0V (Figure 3)

= V

REF

⎯
⎯
⎯

⎯

⎯

1.4 3.5 µA

0.4 1.2 µA

0.15 0.3 mA

0.1 1.0 µA

0.2 0.5 Ω

VMAX

V

DEV = VMAX - VMIN

VMIN

Notes: 6. Deviation of reference input voltage, V

The average temperature coefficient of the reference input voltage

TI T2

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

DEV

Temperature

αV

is defined as:

REF

Vα

REF

V

DEV

(

V

REF

=

−

T

2

6

⋅

10)

°

C)(25
T

……………………..……………….. (

1

ppm

)

C

°

Where:
T2 – T1 = full temperature change.

αV

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

REF

Notes: 7. The dynamic output impedance, R

, is defined as:

Z

V

Δ

KA

Z

=

KA

I

Δ

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:

Δ

v

'

Z +

= ≈

KA

Z

KA

Δ

i

R1

)

(1

R2

AP432/AP432A

Document number: DS31003 Rev. 18 - 2

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Test Circuits

AP432/AP432A

Input

V

KA

I

KA

REF

V

Note:VKA=VREF(1+R1/R 2)+IREFxR1

Fig 1. Test Circuit for VKA= V

REF

Fig 2. Test Circuit for V

Typical Performance Characteristics

R1

R2

IREF

REF

V

IN

I

KA

V

KA

IN

V

KA

IZ(OFF)

> V

KA

REF

Fig 3. Test Circuit for Off-State Current

AP432/AP432A

Document number: DS31003 Rev. 18 - 2

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A

A

Typical Performance Characteristics (cont.)

Small-Signal Voltage Amplification vs Frequency

60

IKA=10mA
T

50

40

30

A

=25oC

9μ F

+

-

15KΩ

8.25KΩ

AP432/AP432A

I

KA

Output

232Ω

+

-

20

10

-Small Signal Voltage Amplification (dB)

V

A

0

1K

10K

100K 1M 10M

f-Frequency-Hz

Reference Impedance vs Frequency

100

I

=10mA

KA

o

=25 C

T

A

10

1

Reference Impedance (Ω)

∣

∣ZKA

0.1
1K 10K 100K 1M 10M

f-Frequency-Hz

100

VKA=V
B VKA=5V
C V

=10V

KA

D V

=15V

KA

ref

Stable

-Load Capacitance-µF

C

L

B

C

D

90
80
70
60
50
40

-Cathode Current- mA
30

KA

I

20
10

0

0.001 0.01 0.1 1 10

+The areas under the curves represent conditions that may cause the
de v ice to o s c illa te . F o r c u r v e s B , C, a n d D, R 2 a n d V+ wer e a d ju s ted

STAB ILITY BO UNDA RY CONDITIONS

to es tablis h th e initial V
were then adjusted to determine the ranges of stability.

and IKA con d itions with CL=0.V

KA

†

TA=25oC

Stable

BATT

and CL

Test Circuit for Voltage Amplification

1KΩ

I

50Ω

+

Test Circuit for Reference Impedance

150Ω

I

KA

C

L

Test C ircu it for C urv e A

R1=10KΩ

C

L

R2

Test Circuit for Curve B, C, and D

KA

-

+

-

I

KA

GND

Output

GND

V

BATT

+

-

150Ω

V

BATT

AP432/AP432A

Document number: DS31003 Rev. 18 - 2

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