Diodes TLV431 User Manual

f

‡

Description

The TLV431 is a three terminal adjustable shunt regulator offering excellent temperature stability and output current handling capability up to 20mA. The output voltage may be set to any chosen voltage between 1.24 and 18 volts by selection of two external divider resistors.

The TLV431 can be used as a replacement for zener diodes in many applications requiring an improvement in zener performance.

The TLV431 is available in 3 grades with initial tolerances of 1%,

0.5%, and 0.2% for the A, B and T grades respectively.

Features

• Low Voltage Operation V

• Temperature range -40 to +125°C

• Reference Voltage Tolerance at +25°C

 0.2% TLV431T  0.5% TLV431B  1% TLV431A

• Typical temperature drift

 4 mV (0°C to +70°C)  6 mV (-40°C to +85°C)  11mV (-40°C to +125°C)

• 80µA Minimum cathode current

• 0.25Ω Typical Output Impedance

• Adjustable Output Voltage V

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

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

• Qualified to AEC-Q100

= 1.24V

REF

to 18V

Typical Application Circuit

Secondary side

regulated supply

Primary side

controller

Optocoupler

I

F

3.3 V

1.24V COST EFFECTIVE SHUNT REGULATOR

Pin Assignments

CATHODE 1

CATHODE

‡ Pin should be left floating or connect to anode

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TLV431_H6 (SC70-6 [SOT363])

2

N/C

REF

TLV431_F (SOT23)

REF 1

3

(Top View)

6 ANODE

5 NC

4 NC

3 ANODE

2

(Top View)

3

(Top View)

5 ANODE

4 REF

TLV431_E5 (SOT25)

N/C 1

2

N/C

TLV431

R3



TLV431

GND

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.

R1

R2

TLV431

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Absolute Maximum Ratings (@T

Symbol Parameter Rating Unit

VKA

IKA

I

REF

VIN

ESD Susceptibility

HBM Human Body Model 4 kV

MM Machine Model 400 V

CDM Charged Device Model 1 kV

(Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices.)

Operating Junction Temperature -40 to +150 °C Storage Temperature -65 to +150 °C

Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for extended periods, may reduce device reliability. Unless otherwise stated voltages specified are relative to the ANODE pin. These are stress ratings only. Operation outside the absolute maximum ratings may cause device failure.

Cathode Voltage 20 V Continuous Cathode Current -20 to +20 mA Reference Input Current Range -0.05 to +3 mA Input Supply Voltage (Relative to Ground) -0.03 to +18 V

Parameter Rating Unit

Recommended Operating Conditions (@T

Symbol Parameter Min Max Units

VKA

IKA TA

Cathode Voltage Cathode Current 0.1 15 mA

Operating Ambient Temperature Range

= +25°C, unless otherwise specified.)

A

= +25°C, unless otherwise specified.)

A

V

REF

-40 +125 °C

18 V

Package Thermal Data

P

Package

SOT23 380°C/W 330mW SOT25 250°C/W 500mW

SC70-6

(SOT363)

θ

JA

380°C/W 330mW

T

= +25°C, TJ = +150°C

A

TLV431

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Electrical Characteristics (@T

Symbol Parameter Conditions Min Typ Max Units

Reference Voltage

Deviation of reference voltage over full temperature range

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

Reference Input Current

deviation over full

I

REF

temperature range

Minimum cathode current for regulation

Off state current Dynamic output

impedance

V

REF

V

REF(dev)

ΔV

I

REF

I

REF(dev)

I

KMIN

I

K(OFF)

ZKA

REF

KA

= +25°C, unless otherwise specified.)

A

= V

REF

,

V

KA

= +25°C

T

A

VKA = V

= 0 to +70°C

T

A

VKA = V

= -40 to +85°C

T

A

VKA = V

= -40 to +125°C

T

A

VKA = V

TLV431A 1.228 1.24 1.252 TLV431B 1.234 1.24 1.246 TLV431T 1.2375 1.24 1.2425 TLV431A 1.221 1.259 TLV431B 1.227 1.253 TLV431T 1.230 1.250 TLV431A 1.215 1.265 TLV431B 1.224 1.259 TLV431T 1.228 1.252 TLV431A 1.209 1.271 TLV431B 1.221 1.265 TLV431T 1.224 1.255

= 0 to +70°C

T

A

TA = -40 to +85°C

TA = -40 to +125°C

6V -1.5 -2.7

V

KA

for V

REF

to

18V -1.5 -2.7

R1 = 10kΩ, R2 = OC

= 0 to +70°C

T

= 10kΩ,

R

1

R

= OC

2

VKA = V

REF

A

TA = -40 to +85°C

TA = -40 to +125°C

= 0 to +70°C

T

A

TA = -40 to +85°C

TA = -40 to +125°C

= 18V, V

V

KA

V

= V

KA

REF,

= 0.1 to 15mA

I

K

= 0V

REF

f = <1kHz

V

4 12 6 20

mV

11 31

mV/V

0.15 0.5 µA

0.05 0.3

0.1 0.4

µA

0.15 0.5 55 80 55 80

µA

55 100

0.001 0.1 µA

0.25 0.4 Ω

TLV431

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Typical Characteristics

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56kΩ

75kΩ

I

K

O/P

S1

10mA

100nF

10kΩ

Test Circuit for V

TLV431

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Measurement

REF

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Typical Characteristics (cont.)

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Typical Characteristics (cont.)

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3V

1kΩ

470µF

750Ω

O/P

Test Circuit for Input Noise Voltage

6.8kΩ I

K

10µF

O/P

180Ω

5V

4.3kΩ

Test Circuit for Phase Shift and Gain

100µF

100Ω

50Ω

O/P

Test Circuit for Reference Impedance

TLV431

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Typical Characteristics (cont.)

Pulse

Generator

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O/P

Test Circuit for Pulse Response

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Application Notes

In a conventional shunt regulator application (Figure 1), an external series resistor (R3) is connected between the supply voltage, VIN, and the TLV431.

R

determines the current that flows through the load (IL) and the TLV431 (IK). The TLV431 will adjust how much current it sinks or “shunts” to

3

maintain a voltage equal to V at least the minimum acceptable I value. When the supply voltage is at its maximum and I TLV431 is less than 15mA.

R

is determined by the supply voltage, (VIN), the load and operating current, (IL and IK), and the TLV431’s reverse breakdown voltage, VKA.

3

across its feedback pin. Since load current and supply voltage may vary, R3 should be small enough to supply

REF

to the TLV431 even when the supply voltage is at its minimum and the load current is at its maximum

KMIN

is at its minimum, R3 should be large enough so that the current flowing through the

L

VV

−

KAIN

R

=

3

and V

where

REFKA

= V

KA



II

+

KL

1VV

OUT

⎞

R

1

⎟

+×=

⎟

R

2

⎠

⎛ ⎜

⎜ ⎝

The values of R1 and R2 should be large enough so that the current flowing through them is much smaller than the current through R3 yet not too large that the voltage drop across them caused I

The most frequent application of the TLV431 is in isolated low output voltage power supplies where the regulated output is galvanically isolated from the controller. As shown in Figure 2 the TLV431 drives current, I which is connected to the controller on the primary side of the power supply.

This completes the feedback path through the isolation barrier and ensures that a stable isolated supply is maintained.

Assuming a forward drop of 1.4V across the opto-coupler diode allows output voltages as low as 2.7V to be regulated.

Figure 1

affects the reference accuracy.

REF

, through the opto-coupler’s LED which in turn drives the isolated transistor

F

Regulated SupplyRegulated Supply

Optocoupler

To controller To controller

TLV431

I

F

1R

⎛ ⎜

REFOUT

R3



R1

R2

OUT

I

−

7.2V

(min)F

⎝

≥>

3R

⎞

+=

1VV

⎟

2R

⎠

−

(max)OUT

7.2V

mA15

GND

Figure 2. Using the TLV431 as the Regulating Element in an Isolated PSU

TLV431

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Application Notes (cont.)

Printed Circuit Board Layout Considerations

The TLV431 in the SOT25 package has the die attached to pin 2, which results in an electrical contact between pin 2 and pin 5. Therefore, pin 2 of the SOT25 package must be left floating or connected to pin 5.

TLV431 in the SC70-6 (SOT363) package has the die attached to pin 2 and 5, which results in an electrical contact between pins 2, 5 and pin 6. Therefore, pins 2 and 5 must be left floating or connected to pin 6.

Other Applications of the TLV431

Vin

R3

TLV431

I

B



0.1µF

R4

ZXTP2039F

C1

Q1

I

SH

Vout

1R

⎛ ⎜

R1

V

REF

⎛

R2

⎜ ⎜

h

⎝

REFOUT

⎝

VV

−

3R

=

+

V

BE

4R =

I

B

⎞

I

SH

⎟

B

⎟

(min)FE

⎠

⎞

+=

1VV

⎟

2R

⎠

OUTIN

II

BSH

mA15I

≤<

GND

It may at times be required to shunt-regulate more current than the 15mA that the TLV431 is capable of.

Figure 3 shows how this can be done using transistor Q1 to amplify the TLV431’s current. Care needs to be taken that the power dissipation and/or SOA requirements of the transistor is not exceeded.

A very effective and simple series regulator can be implemented as shown in Figure 4 above. This may be preferable if the load requires more current than can be provided by the TLV431 alone and there is a need to conserve power when the load is not being powered. This circuit also uses one component less than the shunt circuit shown in Figure 3 above.

Figure 3. High Current Shunt Regulator



Figure 4. Basic Series Regulator

1R

⎞

⎛ ⎜

REFOUT

⎝

3R+−=

⎛

I

⎜ ⎜

h

⎝

I

B

⎞

(max)OUT

⎟

B

⎟

(min)FE

⎠

+=

1VV

⎟

2R

⎠

)VV(V

BEOUTIN

mA15I

≤<

TLV431

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Application Notes (cont.)

Printed Circuit Board Layout Considerations (cont.)



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1R

⎛

+=

1VV

⎜

3R+−=

⎛ ⎜

⎜ ⎝

REFOUT

(max)OUT (min)FE

R =

S

⎞ ⎟

⎟ ⎠

I

h

2R

⎝

BEOUTIN

I

B

mA18I

≤<

B

V

REF

(max)OUT

TLV431

⎞ ⎟

⎠

)VV(V

Figure 5 adds current limit to the series regulator in Figure 4 using a second TLV431. For currents below the limit, the circuit works normally supplying the required load current at the design voltage. However should attempts be made to exceed the design current set by the second TLV431, the device begins to shunt current away from the base of Q1. This begins to reduce the output voltage and thus ensuring that the output current is clamped at the design value. Subject only to Q1’s ability to withstand the resulting power dissipation, the circuit can withstand either a brief or indefinite short circuit.

Figure 5. Series Regulator with Current Limit

1R

⎞

⎛

1VV

⎜

REFOUT

⎝

+≥



Figure 6. Increasing Output Voltage of a Fixed Linear Regulator

One of the useful applications of the TLV431 is in using it to improve the accuracy and/or extend the range and flexibility of fixed voltage regulators. In the circuit in Figure 6 above both the output voltage and i ts accuracy are entirel y determi ned by the TLV431, R1 and R2. However the rest of the features of the regulator (up to 5A output current, output current limiting and thermal shutdown) are all still available.

(All features of the regulator such as short circuit protection, thermal shutdown, etc, are maintained.)

+=

⎟

2R

⎠

)VV(V

REFREGOUT

TLV431

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Application Notes (cont.)

Printed Circuit Board Layout Considerations (cont.)

AP1117 or AP1084

Vin

I

B

Vin

R3

TLV431

VR1

GND



Vout

1.2 V

C1

0.1µF

GND

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TLV431

1R

⎞

⎛ ⎜

REFOUT

Vout

⎝

R1

3R−−=

V

REF

(All features of the regulator

R2

such as short circuit protection, thermal shutdown, etc, are maintained.)

I

B

≤≤

B

1VV

+=

⎟

2R

⎠

)VV(V

+≥

REFREGOUT

)VV(V

REGOUTIN

mA18ImA1.0

Figure 7 is similar to Figure 6 with adjustability added. Note the addition of R3. This is only required for the AP1117 due to the fact that its ground or adjustment pin can only supply a few micro-amps of current at best. R3 is therefore needed to provide sufficient bias current for the TLV431.

Figure 7. Adjustable Linear Voltage Regulator

Ordering Information

Tol. Part Number Package Part Mark Status Reel Size Tape Width

TLV431AE5TA SOT25 V1A Active 7”, 180mm 8mm 3000 TLV431AFTA SOT23 V1A Active 7”, 180mm 8mm 3000

1%

TLV431AH6TA TLV431BE5TA SOT25 V1B Active 7”, 180mm 8mm 3000

TLV431BFTA SOT23 V1B Active 7”, 180mm 8mm 3000

0.5% TLV431BH6TA

0.2% TLV431TFTA SOT23 V1T Active 7”, 180mm 8mm 3000

TLV431

Document number: DS32088 Rev. 6 - 2

SC70-6

(SOT363)

SC70-6

(SOT363)

V1A Active 7”, 180mm 12mm 1000

V1B Active 7”, 180mm 12mm 1000

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Quanity per

Reel

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Package Outline Dimensions (All dimensions in mm.)

Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for latest version.

SOT23

SOT25

K

J

SC70-6 (SOT363)

K

J

TLV431

Document number: DS32088 Rev. 6 - 2

K

J

A

C

B

H

K1

F

D

G

A

H

D

A

B C

H

D

F

L

B C

N

L

M

L

M

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Dim Min Max Typ

A 0.37 0.51 0.40 B 1.20 1.40 1.30 C 2.30 2.50 2.40 D 0.89 1.03 0.915 F 0.45 0.60 0.535 G 1.78 2.05 1.83 H 2.80 3.00 2.90 J 0.013 0.10 0.05 K 0.903 1.10 1.00

K1 — — 0.400

L 0.45 0.61 0.55 M 0.085 0.18 0.11

α

SC70-6 (SOT363)

Dim Min Max Typ

A 0.10 0.30 0.25 B 1.15 1.35 1.30 C 2.00 2.20 2.10 D 0.65 Typ F 0.40 0.45 0.425 H 1.80 2.20 2.15 J 0 0.10 0.05 K 0.90 1.00 1.00 L 0.25 0.40 0.30

M 0.10 0.22 0.11

α

All Dimensions in mm

SOT23

0° 8° —

All Dimensions in mm

Dim Min Max Typ

0° 8° -

SOT25

A 0.35 0.50 0.38 B 1.50 1.70 1.60 C 2.70 3.00 2.80 D

⎯ ⎯

H 2.90 3.10 3.00 J 0.013 0.10 0.05 K 1.00 1.30 1.10 L 0.35 0.55 0.40 M 0.10 0.20 0.15 N 0.70 0.80 0.75

0° 8°

α

All Dimensions in mm

0.95

⎯

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Suggested Pad Layout

Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version.

SOT23

SOT25

Y

Z

X

E

C2C2

C

SC70-6 (SOT363)

G

Z

Y

X

C2

G

Z

Y

X

TLV431

Document number: DS32088 Rev. 6 - 2

C1

C2

C1

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Dimensions Value (in mm)

Z 2.9 X 0.8 Y 0.9 C E

Dimensions Value (in mm)

Z

G

X Y

C1 2.40

C2

Dimensions Value (in mm)

Z 2.5 G 1.3 X 0.42

Y 0.6 C1 1.9 C2 0.65

2.0

1.35

3.20

1.60

0.55

0.80

0.95

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DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).

Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated website, harmless against all damages.

Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel. Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorize d application, Customers shall indemnify and hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.

Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings noted herein may also be covered by one or more United States, international or foreign trademarks.

Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:

A. Life support devices or systems are devices or systems which:

1. are intended to implant into the body, or

2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the

labeling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the

failure of the life support device or to affect its safety or effectiveness. Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and

acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.

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IMPORTANT NOTICE

LIFE SUPPORT

TLV431

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