Diodes AN431 User Manual

Data Sheet

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

General Description

The AN431 series ICs are three-terminal adjustable
shunt regulators with guaranteed thermal stability over
a full operation range. These ICs feature sharp turn-on
characteristics, low temperature coefficient and low
output impedance, which make them ideal substitutes
for Zener diodes in applications such as switching
power supply, charger and other adjustable regulators.

The output voltage of these ICs can be set to any value
between V

age (36V).

The AN431 precision reference is offered in two volt­age tolerance: 0.5% and 1.0%.

These ICs are available in SOT-23 package.

(2.5V) and the maximum cathode volt-

REF

Features

· Programmable Precise Output Voltage from 2.5V
to 36V

· High Stability under Capacitive Load

· Low Temperature Deviation: 4.5mV Typical

· Low Equivalent Full-range Temperature Coeffi-

o

cient with 20PPM/

· Low Dynamic Output Resistance: 0.15Ω Typical

· Sink Current Capacity from 1mA to 100mA

· Low Output Noise

· Wide Operating Range of -40 to 125

C Typical

o

C

Applications

· Charger

· Voltage Adapter

· Switching Power Supply

· Graphic Card

· Precision Voltage Reference

SOT-23

Figure 1. Package Type of AN431

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

1

Data Sheet

REF

V

REF

CATHODE

ANODE

+

-

3

21

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Pin Configuration

N Package

(SOT-23)

ANODE

REFCATHODE

Figure 2. Pin Configuration of AN431 (Top View)

Functional Block Diagram

2

1

3

Figure 3. Functional Block Diagram of AN431

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

2

Data Sheet

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Ordering Information

AN431 -

Circuit Type

E1: Lead-Free

G1: Green

Condition

TR: Tape and Reel

A: 0.5%

B: 1.0%

Package

A: AN431 (40V)

N: SOT-23

Package

SOT-23

BCD Semiconductor's Pb-free products, as designated with "E1" suffix in the part number, are RoHS compliant. Products with
"G1" suffix are available in green packages.

Temperature

Range

-40 to

125oC

Condition

0.5% AN431AN-ATRE1 AN431AN-ATRG1 EB1 GB1 Tape & Reel

1.0%

Lead Free Green Lead Free Green

AN431BN-ATRE1 AN431BN-ATRG1 EB2 GB2 Tape & Reel

Part Number Marking ID

Packing Type

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

3

Data Sheet

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Absolute Maximum Ratings (Note 1)

Parameter Symbol Value Unit

T

V

I

I

KA

REF

P

T

STG

KA

D

40 V

-100 to 150 mA

10 mA

370 mW

J

150

-65 to 150

o

C

o

C

Cathode Voltage

Cathode Current Range (Continuous)

Reference Input Current Range

Power Dissipation

Junction Temperature

Storage Temperature Range

ESD (Human Body Model) ESD 2000 V

Note 1: Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the
device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond
those indicated under "Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum
Ratings" for extended periods may affect device reliability.

Recommended Operating Conditions

Parameter Symbol Min Max Unit

Cathode Voltage

Cathode Current

V

KA

I

KA

Operating Ambient Temperature Range -40 125

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

V

REF

36 V

1.0 100 mA

o

C

4

Data Sheet

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Electrical Characteristics

Operating Conditions: TA=25oC, unless otherwise specified.

Parameter

Reference Voltage

0.5%

1.0% 2.475 2.500 2.525

Test

Circuit

Deviation of Reference Voltage Over Full Temperature Range

Ratio of Change in Reference
Voltage to the Change in
Cathode Voltage

Reference Current 5

Deviation of Reference Current
Over Full Temperature Range

Minimum Cathode Current for
Regulation

Off-state Cathode Current 6

Dynamic Impedance 4

Thermal Resistance

Symbol Conditions Min Typ Max Unit

4

4

V

ΔV

REF

REF

VKA=V

REF, IKA

VKA=V

REF

IKA=10mA

=10mA

0 to 70

-40 to 85

o

C

-40 to 125

ΔV

=

KA

ΔV

REF

5

ΔV

IKA=10mA

KA

10V to V

=

ΔV

KA

36V to 10V

I

REF

5

4

ΔI

I

(Min)

I

(Off)

Z

θ

IKA=10mA, R1=10KΩ, R2=∞

IKA=10mA, R1=10KΩ

REF

R2=∞, T

KA

V

KA=VREF

KA

V

KA

VKA=V

KA

f ≤ 1.0kHz

SOT-23 135

JC

=-40 to 125oC

A

=36V, V

REF

, IKA=1 to 100mA,

REF

=0

2.487 2.500 2.512

o

C

o

C

REF

V

4.5 8

4.5 10

mV

4.5 16

-1.0 -2.7

mV/V

-0.5 -2.0

0.7 4 μA

0.4 1.2 μA

0.4 1.0 mA

0.05 1.0 μA

0.15 0.5 Ω

o

C/W

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

5

Data Sheet

I

OFF

V

IN

V

KA

V

IN

V

KA

R1

I

KA

V

REF

V

IN

V

KA

I

KA

R1

R2

V

REF

VKA=V

REF

*(1+R1/R2)+ I

REF

*R1

I

REF

R3

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Electrical Characteristics (Continued)

Figure 4. Test Circuit 4 for VKA=V

Figure 5. Test Circuit 5 for VKA>V

REF

REF

Figure 6. Test Circuit 6 for I

OFF

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

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Data Sheet

-60 -40 -20 0 20 40 60 80 100 120 140

0.0

0.5

1.0

1.5

R1=10K,R2=

I

KA

=10mA

Reference Current (μA)

Ambient Temperature (0C)

-60 -40 -20 0 20 40 60 80 100 120 140

2.485

2.490

2.495

2.500

2.505

2.510

Reference Voltage (V)

Ambient Temperature (oC)

VKA=V

REF

IKA=10mA

-2 -1 0 1 2 3

-100

-50

0

50

100

150

Cathode Current (mA)

Cathode Voltage (V)

VKA=V

REF

TA=250C

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5

-200

0

200

400

600

800

Cathode Current (μA)

Cathode Voltage (V)

VKA=V

REF

TA=250C

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Typical Performance Characteristics

∞

Figure 7. Reference Voltage vs. Ambient Temperature Figure 8. Reference Current vs. Ambient Temperature

Figure 9. Cathode Current vs. Cathode Voltage Figure 10. Cathode Current vs. Cathode Voltage

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

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Data Sheet

-40 -20 0 20 40 60 80 100 120

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Off-state Cathode Current (μA)

Ambient Temperature (oC)

VKA=36V

V

REF

=0

-40-200 20406080100120

-1.4

-1.3

-1.2

-1.1

-1.0

-0.9

VKA=3.5V to 36V

ΔV

REF

/ ΔV

KA

(mV/V)

Ambient Temperature (oC)

10μF

8.2K

15K

I

KA

Output

242

GND

1k 10k 100k 1M

-10

0

10

20

30

40

50

60

70

Voltage Gain (dB)

Small Signal Frequency (Hz)

TA=250C

I

KA

=10mA

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Typical Performance Characteristics (Continued)

Figure 11. Off-state Cathode Current vs. Figure 12. Ratio of Delta Reference Voltage to the

Ambient Temperature

Ratio of Delta Cathode Voltage

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

Figure 13. Small Signal Voltage Gain vs. Frequency

8

Data Sheet

1K 10K 100K 1,000K

0.1

1

10

Reference Impedance (Ω)

Frequency (Hz)

IKA=10mA

T

A

=25oC

GND

Output

50

1K

I

KA

I

KA

R1 (10K)

R2

150

0

10

20

30

40

50

60

70

80

90

100

10

1

0.10.01

StableStable

Cathode Current (mA)

Load Capacitance (μF)

VKA=V

REF

VKA= 5V

VKA=10V

VKA=15V

0.001

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Typical Performance Characteristics (Continued)

Figure 14. Reference Impedance vs. Frequency

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

Figure 15. Stability Boundary Conditions vs. Load Capacitance

9

Data Sheet

Pulse
Generator
f=100KHz

220

50

Output

GND

0246

0

1

2

3

4

5

Input

Input and Output Voltage (V)

Time (μS)

Output

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Typical Performance Characteristics (Continued)

Figure 16. Pulse Response of Input and Output Voltage

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

10

Data Sheet

V

IN

V

OUT

R1

R2

V

REF

AN431

R3

V

IN V

OUT

R4

R1

R2

V

REF

R3

AN431

I

OUT

V

IN

AN431

R2

R1

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Typical Application

V

=(1+R1/R2)*V

OUT

Figure 17. Shunt Regulator

REF

Figure 18. High Current Shunt Regulator

V

=(1+R2/R3)*V

OUT

I

OUT=VREF

/R2 + I

REF

KA

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

Figure 19. Current Source or Current Limit

11

Data Sheet

AZ1117

V

IN

V

OUT

Adjust

8.2K

AN431

R1

R2

R3

250

250

5V, 1A

PWM Controller

C1

R1

R2 680

U2

3

4

PS521

C2

2

R3

R4

R5

V

OUT

AN431

Q1

COMP

VFB

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Typical Application (Continued)

Figure 20. Precision 5V 1A Regulator

Figure 21. PWM Converter with Reference

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

12

Data Sheet

2.300(0.091)

2.500(0.098)

1.200(0.047)

1.400(0.055)

0.920(0.036)

0.980(0.039)

0.300(0.012)

0.500(0.020)

1.900(0.075)REF

2.800(0.110)

3.000(0.118)

2.0°

3.0 °

0.500(0.020)

0.700(0.028)

1.050(0.041)REF

0.020(0.001)

0.100(0.004)

0.900(0.035)

1.100(0.043)

4×

R0.100(0.004)

7.0°

7.0°

0.550(0.022)REF

0.200(0.008)MIN

0.100(0.004) GAUGE PLANE

0.080(0.003)

0.150(0.006)

R0.100(0.004)

0.0°~10.0°

ADJUSTABLE PRECISION SHUNT REGULATORS AN431

Mechanical Dimensions

SOT-23 Unit: mm(inch)

Dec. 2012 Rev. 2. 0 BCD Semiconductor Manufacturing Limited

13

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particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use

of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or

of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or

other rights nor the rights of others.

other rights nor the rights of others.

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