ADR3425_技术文档

Micropower, High Accuracy

Voltage References

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

FEATURES

PIN CONFIGURATION

Initial accuracy: 0.1ꢀ (maximum)

GND FORCE

GND SENSE

ENABLE

1

6

5

4

V

FORCE

OUT

IN

Maximum temperature coefficient: 8 ppm/°C

Operating temperature range: −40°C to +125°C

Output current: +10 mA source/−3 mA sink

Low quiescent current: 100 μA (maximum)

Low dropout voltage: 250 mV at 2 mA

Output noise (0.1 Hz to 10 Hz): <10 μV p-p at 1.2 V (typical)

6-lead SOT-23

ADR34xx

SENSE

2

3

TOP VIEW

(Not to Scale)

Figure 1. 6-Lead SOT-23

APPLICATIONS

Precision data acquisition systems

Industrial instrumentation

Medical devices

Battery-powered devices

GENERAL DESCRIPTION

Table 2. Voltage Reference Choices from Analog Devices

The ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/

ADR3440/ADR3450 are low cost, low power, high precision

CMOS voltage references, featuring 0ꢀ1ꢁ initial accuracy, low

operating current, and low output noise in a small SOT-23

packageꢀ For high accuracy, output voltage and temperature

coefficient are trimmed digitally during final assembly using

Analog Devices, Incꢀ, patented DigiTrim® technologyꢀ

High Voltage,

High Perfor-

mance

V_OUT

(V)

Low Cost/

Low Power Power

Ultralow Low

Noise

0.5/1.0

1.2

ADR130

ADR3412

ADR280

2.048

2.5

ADR360

ADR3420

ADR3425

AD1582

ADR361

ADR3430

AD1583

ADR363

REF191

ADR430

ADR440

Stability and system reliability are further improved by the low

output voltage hysteresis of the device and low long-term output

voltage driftꢀ Furthermore, the low operating current of the

device (100 μA maximum) facilitates usage in low power

devices, and its low output noise helps maintain signal integrity

in critical signal processing systemsꢀ

ADR291 ADR431

REF192

ADR03

AD780

ADR441

ADR433

ADR443

3.0

REF193

ADR06

AD780

These CMOS are available in a wide range of output voltages, all

of which are specified over the industrial temperature range of

−40°C to +125°Cꢀ

3.3

ADR366

REF196

ADR3433

4.096

ADR3440

AD1584

ADR364

ADR3450

AD1585

ADR365

ADR292 ADR434

Table 1. Selection Guide

Model

Output Voltage (V)

Input Voltage Range (V)

2.3 to 5.5

2.7 to 5.5

3.2 to 5.5

3.5 to 5.5

4.3 to 5.5

5.2 to 5.5

REF198

ADR293 ADR435

REF195 ADR445

ADR444

ADR3412

ADR3420

ADR3425

ADR3430

ADR3433

ADR3440

ADR3450

1.200

2.048

2.500

3.000

3.300

4.096

5.000

5.0

ADR02

AD586

ADR01

AD587

10.0

Rev. B

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarks and registeredtrademarks arethe property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

Fax: 781.461.3113

www.analog.com

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications....................................................................................... 1

Pin Configuration............................................................................. 1

General Description......................................................................... 1

Revision History ............................................................................... 2

Specifications..................................................................................... 3

ADR3412 Electrical Characteristics .......................................... 3

ADR3420 Electrical Characteristics .......................................... 4

ADR3425 Electrical Characteristics .......................................... 5

ADR3430 Electrical Characteristics .......................................... 6

ADR3433 Electrical Characteristics .......................................... 7

ADR3440 Electrical Characteristics .......................................... 8

ADR3450 Electrical Characteristics .......................................... 9

ESD Caution................................................................................ 10

Pin Configuration and Function Descriptions........................... 11

Typical Performance Characteristics ........................................... 12

Terminology.................................................................................... 18

Theory of Operation ...................................................................... 19

Power Dissipation....................................................................... 19

Applications Information.............................................................. 20

Basic Voltage Reference Connection....................................... 20

Input and Output Capacitors.................................................... 20

4-Wire Kelvin Connections ...................................................... 20

V_INSlew Rate Considerations................................................... 20

Shutdown/Enable Feature ......................................................... 20

Sample Applications................................................................... 21

Outline Dimensions....................................................................... 22

Ordering Guide .......................................................................... 22

Absolute Maximum Ratings and Minimum Operating

Condition......................................................................................... 10

Thermal Resistance .................................................................... 10

REVISION HISTORY

6/10—Rev. A to Rev. B

Added ADR3430 Electrical Characteristics Section.....................4

Added Table 4; Renumbered Sequentially .....................................4

Added ADR3440 Electrical Characteristics Section and

Added ADR3412, ADR3420, ADR3433..................... Throughout

Changes to Table 1 and Table 2....................................................... 1

Added ADR3412 Electrical Characteristics Section

and Table 3......................................................................................... 3

Added ADR3420 Electrical Characteristics Section

and Table 4......................................................................................... 4

Added ADR3433 Electrical Characteristics Section and

Table 7, Renumbered Subsequent Tables ...................................... 7

Replaced Figure 5 Through Figure 7 ........................................... 12

Replaced Figure 11 Through Figure 13 ....................................... 13

Table 5 .................................................................................................5

Changes to Table 6.............................................................................6

Changes to Figure 2...........................................................................8

Changes to Figure 4 and Figure 5....................................................9

Changes to Figure 11...................................................................... 10

Changes to Figure 36 and Figure 37 Caption ............................. 14

Changes to Figure 39 and Theory of Operation Section .......... 16

Changes to Figure 40 and Figure 41............................................. 17

Changes to Negative Reference Section, Boosted Output

4/10—Rev. 0 to Rev. A

Current Reference Section, Figure 43, and Figure 44................ 18

Changes to Ordering Guide.......................................................... 19

Added ADR3430 and ADR3440.......................................Universal

Changes to Table 1, Table 2, and Figure 1 ..................................... 1

Changes to Table 3............................................................................ 3

3/10—Revision 0: Initial Version

Rev. B | Page 2 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

SPECIFICATIONS

ADR3412 ELECTRICAL CHARACTERISTICS

V_IN= 2.3 V to 5.5 V, T_A= 25°C, I_LOAD= 0 mA, unless otherwise noted.

Table 3.

Parameter

Symbol

V_OUT

Conditions

Min

Typ

Max

Unit

V

OUTPUT VOLTAGE

INITIAL ACCURACY

1.1988

1.2000 1.2012

V_OERR

0.1

1.2

8

%

mV

TEMPERATURE COEFFICIENT

LINE REGULATION

TCV_OUT

−40°C ≤ T_A≤ +125°C

ppm/°C

ppm/V

ΔV_O/ΔV_INV_IN= 2.3 V to 5.5 V

V_IN= 2.3 V to 5.5 V, −40°C ≤ T_A≤ +125°C

7

50

160

LOAD REGULATION

Sourcing

ΔV_O/ΔI_L

I_L= 0 mA to 10 mA,

V_IN= 2.8 V, −40°C ≤ T_A≤ +125°C

I_L= 0 mA to −3 mA,

14

7

30

50

ppm/mA

Sinking

V_IN= 2.8 V, −40°C ≤ T_A≤ +125°C

OUTPUT CURRENT CAPACITY

Sourcing

Sinking

I_L

V_IN= 2.8 V to 5.5 V

10

−3

mA

QUIESCENT CURRENT

Normal Operation

I_Q

ENABLE > V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

ENABLE < 0.7 V

85

100

5

μA

V

Shutdown

DROPOUT VOLTAGE¹

V_DO

I_L= 0 mA, −40°C ≤ T_A≤ +125°C

I_L= 2 mA, −40°C ≤ T_A≤ +125°C

1

1.1

1.15

V

ENABLE PIN

Shutdown Voltage

ENABLE Voltage

ENABLE Pin Leakage Current

OUTPUT VOLTAGE NOISE

V_L

V_H

I_EN

0

0.7

V_IN

3

V

μA

V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

f = 0.1 Hz to 10 Hz

f = 10 Hz to 10 kHz

f = 1 kHz

0.85

8

28

e_np-p

μV p-p

μV rms

μV/√Hz

OUTPUT VOLTAGE NOISE

DENSITY

e_n

0.6

OUTPUT VOLTAGE HYSTERESIS²

RIPPLE REJECTION RATIO

LONG-TERM STABILITY

ΔV_{OUT_HYS}T_A= +25°C to −40°C to +125°C to +25°C

RRR f_IN= 60 Hz

ΔV_{OUT_LTD}1000 hours at 50°C

t_R

70

ppm

dB

−60

30

ppm

μs

TURN-ON SETTLING TIME

100

C_IN= 0.1 μF, C_L= 0.1 μF, R_Load= 1 kΩ

¹Refers to the minimum difference between V_INand V_OUTsuch that V_OUTmaintains a minimum accuracy of 0.1%. See the Terminology section.

²See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.

Rev. B | Page 3 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

ADR3420 ELECTRICAL CHARACTERISTICS

V_IN= 2.3 V to 5.5 V, T_A= 25°C, I_LOAD= 0 mA, unless otherwise noted.

Table 4.

Parameter

Symbol

V_OUT

Conditions

Min

Typ

Max

Unit

V

OUTPUT VOLTAGE

INITIAL ACCURACY

2.0459

2.0480 2.0500

0.1

V_OERR

%

2.048 mV

TEMPERATURE COEFFICIENT

LINE REGULATION

TCV_OUT

−40°C ≤ T_A≤ +125°C

8

ppm/°C

ppm/V

ΔV_O/ΔV_IN

V_IN= 2.3 V to 5.5 V

V_IN= 2.3 V to 5.5 V, −40°C ≤ T_A≤ +125°C

7

50

160

LOAD REGULATION

Sourcing

ΔV_O/ΔI_L

I_L= 0 mA to 10 mA,

V_IN= 2.8 V, −40°C ≤ T_A≤ +125°C

I_L= 0 mA to −3 mA,

12

7

30

50

ppm/mA

Sinking

V_IN= 2.8 V, −40°C ≤ T_A≤ +125°C

OUTPUT CURRENT CAPACITY

Sourcing

Sinking

I_L

V_IN= 2.8 V to 5.5 V

10

−3

mA

QUIESCENT CURRENT

Normal Operation

I_Q

ENABLE > V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

ENABLE < 0.7 V

85

100

5

μA

mV

Shutdown

DROPOUT VOLTAGE¹

V_DO

I_L= 0 mA, −40°C ≤ T_A≤ +125°C

I_L= 2 mA, −40°C ≤ T_A≤ +125°C

100

150

250

300

ENABLE PIN

Shutdown Voltage

ENABLE Voltage

ENABLE Pin Leakage Current

OUTPUT VOLTAGE NOISE

V_L

V_H

I_EN

0

0.7

V_IN

3

V

μA

V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

f = 0.1 Hz to 10 Hz

f = 10 Hz to 10 kHz

f = 1 kHz

0.85

15

38

e_np-p

μV p-p

μV rms

μV/√Hz

OUTPUT VOLTAGE NOISE

DENSITY

e_n

0.9

OUTPUT VOLTAGE HYSTERESIS²

RIPPLE REJECTION RATIO

LONG-TERM STABILITY

ΔV_{OUT_HYS}

RRR

T_A= +25°C to −40°C to +125°C to +25°C

f_IN= 60 Hz

70

ppm

dB

−60

30

ΔV_{OUT_LTD}

t_R

1000 hours at 50°C

ppm

μs

TURN-ON SETTLING TIME

400

C_IN= 0.1 μF, C_L= 0.1 μF, R_Load= 1 kΩ

¹Refers to the minimum difference between V_INand V_OUTsuch that V_OUTmaintains a minimum accuracy of 0.1%. See the Terminology section.

²See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.

Rev. B | Page 4 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

ADR3425 ELECTRICAL CHARACTERISTICS

V_IN= 2.7 V to 5.5 V, I_L= 0 mA, T_A= 25°C, unless otherwise noted.

Table 5.

Parameter

Symbol

V_OUT

Conditions

Min

Typ

Max

2.5025

0.1

Unit

V

OUTPUT VOLTAGE

INITIAL ACCURACY

2.4975

2.500

V_OERR

%

2.5

mV

TEMPERATURE COEFFICIENT

LINE REGULATION

TCV_OUT

−40°C ≤ T_A≤ +125°C

2.5

5

8

ppm/°C

ppm/V

ΔV_O/ΔV_IN

V_IN= 2.7 V to 5.5 V

V_IN= 2.7 V to 5.5 V, −40°C ≤ T_A≤ +125°C

50

120

LOAD REGULATION

Sourcing

ΔV_O/ΔI_L

I_L= 0 mA to 10 mA,

V_IN= 3.0 V, −40°C ≤ T_A≤ +125°C

I_L= 0 mA to −3 mA,

10

30

50

ppm/mA

Sinking

V_IN= 3.0 V, −40°C ≤ T_A≤ +125°C

OUTPUT CURRENT CAPACITY

Sourcing

Sinking

I_L

V_IN= 3.0 V to 5.5 V

10

−3

mA

QUIESCENT CURRENT

Normal Operation

I_Q

ENABLE ≥ V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

ENABLE ≤ 0.7 V

85

100

5

μA

mV

Shutdown

DROPOUT VOLTAGE¹

V_DO

I_L= 0 mA, T_A= −40°C ≤ T_A≤ +125°C

I_L= 2 mA, T_A= −40°C ≤ T_A≤ +125°C

50

75

200

250

ENABLE PIN

Shutdown Voltage

ENABLE Voltage

ENABLE Pin Leakage Current

OUTPUT VOLTAGE NOISE

V_L

V_H

I_EN

0

0.7

V_IN

3

V

μA

V_IN× 0.85

ENABLE = V_IN, T_A= −40°C ≤ T_A≤ +125°C

f = 0.1 Hz to 10 Hz

f = 10 Hz to 10 kHz

1

e_np-p

18

42

1

μV p-p

μV rms

ꢀV/√Hz

OUTPUT VOLTAGE NOISE

DENSITY

e_n

f = 1 kHz

OUTPUT VOLTAGE HYSTERESIS²ΔV_{OUT_HYS}

T_A= +25°C to −40°C to +125°C to +25°C

f_IN= 60 Hz

70

ppm

dB

RIPPLE REJECTION RATIO

LONG-TERM STABILITY

TURN-ON SETTLING TIME

RRR

−60

30

ΔV_{OUT_LTD}

t_R

1000 hours at 50°C

ppm

μs

600

C_IN= 0.1 μF, C_L= 0.1 μF, R_Load= 1 kΩ

¹Refers to the minimum difference between V_INand V_OUTsuch that V_OUTmaintains a minimum accuracy of 0.1%. See the Terminology section.

²See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.

Rev. B | Page 5 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

ADR3430 ELECTRICAL CHARACTERISTICS

V_IN= 3.2 V to 5.5 V, I_L= 0 mA, T_A= 25°C, unless otherwise noted.

Table 6.

Parameter

Symbol

V_OUT

Conditions

Min

Typ

Max

Unit

V

OUTPUT VOLTAGE

INITIAL ACCURACY

2.9970

3.0000 3.0030

V_OERR

0.1

3.0

%

mV

TEMPERATURE COEFFICIENT

LINE REGULATION

TCV_OUT

−40°C ≤ T_A≤ +125°C

2.5

5

8

ppm/°C

ppm/V

ΔV_O/ΔV_INV_IN= 3.2 V to 5.5 V

V_IN= 3.2 V to 5.5 V, −40°C ≤ T_A≤ +125°C

50

120

LOAD REGULATION

Sourcing

ΔV_O/ΔI_L

I_L= 0 mA to 10 mA,

V_IN= 3.5 V, −40°C ≤ T_A≤ +125°C

I_L= 0 mA to −3 mA,

9

30

50

ppm/mA

Sinking

10

V_IN= 3.5 V, −40°C ≤ T_A≤ +125°C

OUTPUT CURRENT CAPACITY

Sourcing

Sinking

I_L

V_IN= 3.5 V to 5.5 V

10

−3

mA

QUIESCENT CURRENT

Normal Operation

I_Q

ENABLE ≥ V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

ENABLE ≤ 0.7 V

85

100

5

μA

mV

Shutdown

DROPOUT VOLTAGE¹

V_DO

I_L= 0 mA, T_A= −40°C ≤ T_A≤ +125°C

I_L= 2 mA, T_A= −40°C ≤ T_A≤ +125°C

50

75

200

250

ENABLE PIN

Shutdown Voltage

ENABLE Voltage

ENABLE Pin Leakage Current

OUTPUT VOLTAGE NOISE

V_L

V_H

I_EN

0

0.7

V_IN

3

V

μA

V_IN× 0.85

ENABLE = V_IN, T_A= −40°C ≤ T_A≤ +125°C

f = 0.1 Hz to 10 Hz

f = 10 Hz to 10 kHz

0.85

22

45

e_np-p

μV p-p

μV rms

ꢀV/√Hz

ppm

dB

OUTPUT VOLTAGE NOISE DENSITY e_n

f = 1 kHz

1.1

70

OUTPUT VOLTAGE HYSTERESIS²

RIPPLE REJECTION RATIO

LONG-TERM STABILITY

ΔV_{OUT_HYS}T_A= +25°C to −40°C to +125°C to +25°C

RRR f_IN= 60 Hz

ΔV_{OUT_LTD}1000 hours at 50°C

t_R

−60

30

ppm

μs

TURN-ON SETTLING TIME

700

C_IN= 0.1 μF, C_L= 0.1 μF, R_Load= 1 kΩ

¹Refers to the minimum difference between V_INand V_OUTsuch that V_OUTmaintains a minimum accuracy of 0.1%. See the Terminology section.

²See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.

Rev. B | Page 6 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

ADR3433 ELECTRICAL CHARACTERISTICS

V_IN= 3.5 V to 5.5 V, I_L= 0 mA, T_A= 25°C, unless otherwise noted.

Table 7.

Parameter

Symbol

V_OUT

Conditions

Min

Typ Max

Unit

V

OUTPUT VOLTAGE

INITIAL ACCURACY

3.2967

3.30 3.3033

V_OERR

0.1

3.3

8

%

mV

TEMPERATURE COEFFICIENT

LINE REGULATION

TCV_OUT

−40°C ≤ T_A≤ +125°C

ppm/°C

ppm/V

ΔV_O/ΔV_INV_IN= 3.5 V to 5.5 V

5

50

V_IN= 3.5 V to 5.5 V, −40°C ≤ T_A≤ +125°C

120

LOAD REGULATION

Sourcing

ΔV_O/ΔI_L

I_L= 0 mA to 10 mA,

V_IN= 3.8 V, −40°C ≤ T_A≤ +125°C

I_L= 0 mA to −3 mA,

9

30

50

ppm/mA

Sinking

10

V_IN= 3.8 V, −40°C ≤ T_A≤ +125°C

OUTPUT CURRENT CAPACITY

Sourcing

Sinking

I_L

V_IN= 3.8 V to 5.5 V

10

−3

mA

QUIESCENT CURRENT

Normal Operation

I_Q

ENABLE > V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

ENABLE < 0.7 V

85

100

5

μA

mV

Shutdown

DROPOUT VOLTAGE¹

V_DO

I_L= 0 mA, −40°C ≤ T_A≤ +125°C

I_L= 2 mA, −40°C ≤ T_A≤ +125°C

50

75

200

250

ENABLE PIN

Shutdown Voltage

ENABLE Voltage

ENABLE Pin Leakage Current

OUTPUT VOLTAGE NOISE

V_L

V_H

I_EN

0

0.7

V_IN

3

V

μA

V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

f = 0.1 Hz to 10 Hz

f = 10 Hz to 10 kHz

f = 1 kHz

0.85

25

46

e_np-p

μV p-p

μV rms

μV/√Hz

ppm

dB

OUTPUT VOLTAGE NOISE DENSITY e_n

1.2

70

OUTPUT VOLTAGE HYSTERESIS²

RIPPLE REJECTION RATIO

LONG-TERM STABILITY

ΔV_{OUT_HYS}T_A= +25°C to −40°C to +125°C to +25°C

RRR f_IN= 60 Hz

ΔV_{OUT_LTD}1000 hours at 50°C

t_R

-60

30

ppm

μs

TURN-ON SETTLING TIME

750

C_IN= 0.1 μF, C_L= 0.1 μF, R_Load= 1 kΩ

¹Refers to the minimum difference between V_INand V_OUTsuch that V_OUTmaintains a minimum accuracy of 0.1%. See the Terminology section.

²See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.

Rev. B | Page 7 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

ADR3440 ELECTRICAL CHARACTERISTICS

V_IN= 4.3 V to 5.5 V, I_L= 0 mA, T_A= 25°C, unless otherwise noted.

Table 8.

Parameter

Symbol

V_OUT

Conditions

Min

Typ

Max

4.1000

0.1

Unit

V

OUTPUT VOLTAGE

INITIAL ACCURACY

4.0919

4.0960

V_OERR

%

4.096

8

mV

TEMPERATURE COEFFICIENT

LINE REGULATION

TCV_OUT

−40°C ≤ T_A≤ +125°C

2.5

3

ppm/°C

ppm/V

ΔV_O/ΔV_IN

V_IN= 4.3 V to 5.5 V

V_IN= 4.3 V to 5.5 V, −40°C ≤ T_A≤ +125°C

50

120

LOAD REGULATION

Sourcing

ΔV_O/ΔI_L

I_L= 0 mA to 10 mA,

V_IN= 4.6 V, −40°C ≤ T_A≤ +125°C

I_L= 0 mA to −3 mA,

6

30

50

ppm/mA

Sinking

15

V_IN= 4.6 V, −40°C ≤ T_A≤ +125°C

OUTPUT CURRENT CAPACITY

Sourcing

Sinking

I_L

V_IN= 4.6 V to 5.5 V

10

−3

mA

QUIESCENT CURRENT

Normal Operation

I_Q

ENABLE ≥ V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

ENABLE ≤ 0.7 V

85

100

5

μA

mV

Shutdown

DROPOUT VOLTAGE¹

V_DO

I_L= 0 mA, T_A= −40°C ≤ T_A≤ +125°C

I_L= 2 mA, T_A= −40°C ≤ T_A≤ +125°C

50

75

200

250

ENABLE PIN

Shutdown Voltage

ENABLE Voltage

ENABLE Pin Leakage Current

OUTPUT VOLTAGE NOISE

V_L

V_H

I_EN

0

0.7

V_IN

3

V

μA

V_IN× 0.85

ENABLE = V_IN, T_A= −40°C ≤ T_A≤ +125°C

f = 0.1 Hz to 10 Hz

f = 10 Hz to 10 kHz

e_np-p

29

53

1.4

μV p-p

μV rms

ꢀV/√Hz

OUTPUT VOLTAGE NOISE

DENSITY

e_n

f = 1 kHz

OUTPUT VOLTAGE HYSTERESIS²ΔV_{OUT_HYS}

T_A= +25°C to −40°C to +125°C to +25°C

f_IN= 60 Hz

70

ppm

dB

RIPPLE REJECTION RATIO

LONG-TERM STABILITY

TURN-ON SETTLING TIME

RRR

−60

30

ΔV_{OUT_LTD}

t_R

1000 hours at 50°C

ppm

μs

800

C_IN= 0.1 μF, C_L= 0.1 μF, R_Load= 1 kΩ

¹Refers to the minimum difference between V_INand V_OUTsuch that V_OUTmaintains a minimum accuracy of 0.1%. See the Terminology section.

²See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.

Rev. B | Page 8 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

ADR3450 ELECTRICAL CHARACTERISTICS

V_IN= 5.2 V to 5.5 V, I_L= 0 mA, T_A= 25°C, unless otherwise noted.

Table 9.

Parameter

Symbol

V_OUT

Conditions

Min

Typ

Max

5.0050

0.1

Unit

V

OUTPUT VOLTAGE

INITIAL ACCURACY

4.9950

5.0000

V_OERR

%

5.0

mV

TEMPERATURE COEFFICIENT

LINE REGULATION

TCV_OUT

−40°C ≤ T_A≤ +125°C

2.5

3

8

ppm/°C

ppm/V

ΔV_O/ΔV_IN

V_IN= 5.2 V to 5.5 V

V_IN= 5.2 V to 5.5 V, −40°C ≤ T_A≤ +125°C

50

120

LOAD REGULATION

Sourcing

ΔV_O/ΔI_L

I_L= 0 mA to 10 mA,

V_IN= 5.5 V, −40°C ≤ T_A≤ +125°C

I_L= 0 mA to −3 mA,

3

30

50

ppm/mA

Sinking

19

V_IN= 5.5 V, −40°C ≤ T_A≤ +125°C

OUTPUT CURRENT CAPACITY

Sourcing

Sinking

I_L

V_IN= 5.5 V

10

−3

mA

QUIESCENT CURRENT

Normal Operation

I_Q

ENABLE ≥ V_IN× 0.85

ENABLE = V_IN, −40°C ≤ T_A≤ +125°C

ENABLE ≤ 0.7 V

85

100

5

μA

mV

Shutdown

DROPOUT VOLTAGE¹

V_DO

I_L= 0 mA, T_A= −40°C ≤ T_A≤ +125°C

I_L= 2 mA, T_A= −40°C ≤ T_A≤ +125°C

50

75

200

250

ENABLE PIN

Shutdown Voltage

ENABLE Voltage

ENABLE Pin Leakage Current

OUTPUT VOLTAGE NOISE

V_L

V_H

I_EN

0

0.7

V_IN

3

V

μA

V_IN× 0.85

ENABLE = V_IN, T_A= −40°C ≤ T_A≤ +125°C

f = 0.1 Hz to 10 Hz

f = 10 Hz to 10 kHz

1

e_np-p

35

60

1.5

μV p-p

μV rms

ꢀV/√Hz

OUTPUT VOLTAGE NOISE

DENSITY

e_n

f = 1 kHz

OUTPUT VOLTAGE HYSTERESIS²ΔV_{OUT_HYS}

T_A= +25°C to −40°C to +125°C to +25°C

f_IN= 60 Hz

70

ppm

dB

RIPPLE REJECTION RATIO

LONG-TERM STABILITY

TURN-ON SETTLING TIME

RRR

−58

30

ΔV_{OUT_LTD}

t_R

1000 hours at 50°C

ppm

ꢀs

900

C_IN= 0.1 μF, C_L= 0.1 μF, R_Load= 1 kΩ

¹Refers to the minimum difference between V_INand V_OUTsuch that V_OUTmaintains a minimum accuracy of 0.1%. See the Terminology section.

²See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.

Rev. B | Page 9 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

ABSOLUTE MAXIMUM RATINGS AND MINIMUM OPERATING CONDITION

T_A= 25°C, unless otherwise noted.

THERMAL RESISTANCE

θ_JAis specified for the worst-case conditions, that is, a device

soldered in a circuit board for surface-mount packages.

Table 10.

Parameter

Rating

Supply Voltage

6 V

V_IN

0.1 V/ms

−40°C to +125°C

−65°C to +125°C

−65°C to +150°C

Table 11. Thermal Resistance

Package Type

ENABLE to GND SENSE Voltage

V_INMinimum Slew Rate

Operating Temperature Range

Storage Temperature Range

Junction Temperature Range

θ_JA

θ_JC

Unit

6-Lead SOT-23 (RJ-6)

230

92

°C/W

ESD CAUTION

Stresses above those listed under Absolute Maximum Ratings

may cause permanent damage to the device. This is a stress

rating only; functional operation of the device at these or any

other conditions above those indicated in the operational

section of this specification is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect

device reliability.

Rev. B | Page 10 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

GND FORCE

1

6

V

FORCE

OUT

IN

ADR34xx

5

4

V

SENSE

GND SENSE

ENABLE

2

3

TOP VIEW

(Not to Scale)

Figure 2. Pin Configuration

Table 12. Pin Function Descriptions

Pin No.

Mnemonic

GND FORCE

GND SENSE

ENABLE

Description

Ground Force Connection.¹

1

2

3

4

5

6

Ground Voltage Sense Connection. Connect directly to the point of lowest potential in the application.¹

Enable Connection. Enables or disables the device.

Input Voltage Connection.

Reference Voltage Output Sensing Connection. Connect directly to the voltage input of the load devices.¹

Reference Voltage Output.¹

V_IN

V_OUTSENSE

V_OUTFORCE

¹See the Applications Information section for more information on force/sense connections.

Rev. B | Page 11 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

TYPICAL PERFORMANCE CHARACTERISTICS

T_A= 25°C, unless otherwise noted.

2.5010

2.5008

2.5006

2.5004

2.5002

2.5000

2.4998

2.4996

2.4994

2.4992

2.4990

5.0025

5.0020

5.0015

5.0010

5.0005

5.0000

4.9995

4.9990

4.9985

4.9980

4.9975

V

= 5.5V

V

= 5.5V

IN

–40 –25 –10

5

20

35

50

65

80

95 110 125

–40 –25 –10

5

20

35

50

65

80

95 110 125

TEMPERATURE (ºC)

Figure 3. ADR3425 Output Voltage vs. Temperature

Figure 6. ADR3450 Output Voltage vs. Temperature

40

35

30

25

20

15

10

5

45

40

35

30

25

20

15

10

5

0

1

2

3

4

5

6

7

8

9

10

11

0

1

2

3

4

5

6

7

8

9

10 MORE

TEMPERATURE COEFFICIENT (ppm/°C)

Figure 4. ADR3425 Temperature Coefficient Distribution

Figure 7. ADR3450 Temperature Coefficient Distribution

24

22

35

ADR3412

ADR3420

ADR3425

ADR3430

ADR3433

ADR3412

ADR3420

ADR3425

ADR3430

ADR3433

I

= 0mA TO +10mA

I

= 0mA TO –3mA

L

20

18

16

14

12

10

8

30

SOURCING

SINKING

ADR3440

ADR3450

ADR3440

ADR3450

25

20

15

10

5

6

4

2

0

–40 –25 –10

5

20

35

50

65

80

95 110 125

–40 –25 –10

5

20

35

50

65

80

95 110 125

TEMPERATURE (°C)

Figure 5. Load Regulation vs. Temperature (Sourcing)

Figure 8. Load Regulation vs. Temperature (Sinking)

Rev. B | Page 12 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

1.20

1.15

1.10

1.05

1.00

0.95

0.90

0.85

0.80

400

–40°C

+25°C

+125°C

350

300

T

= –40°C

= +25°C

= +125°C

A

250

200

150

100

50

0

–3 –2 –1

0

1

2

3

4

5

6

7

8

9

10

–3 –2 –1

0

1

2

3

4

5

6

7

8

9

10

LOAD CURRENT (mA)

Figure 9. ADR3412 Dropout Voltage vs. Load Current

Figure 12. ADR3425 Dropout Voltage vs. Load Current

450

400

350

300

250

200

150

100

50

350

300

250

200

150

100

50

–40°C

+25°C

+125°C

T

= –40°C

= +25°C

= +125°C

A

0

–50

–3 –2 –1

0

1

2

3

4

5

6

7

8

9

10

–3 –2 –1

0

1

2

3

4

5

6

7

8

9

10

LOAD CURRENT (mA)

Figure 13. ADR3450 Dropout Voltage vs. Load Current

Figure 10. ADR3420 Dropout Voltage vs. Load Current

140

120

100

80

ADR3412

ADR3420

ADR3425

ADR3430

ADR3433

FREQUENCY GEN = 1Hz

V

C

R

= 2V/DIV

IN

ADR3440

ADR3450

= C = 0.1µF

IN OUT

= 1kΩ

L

2

60

V

= 500mV/DIV

OUT

40

20

1

0

CH1 500mV

CH2 2.00V

M100µs

A

CH2

2.36V

–40 –25 –10

5

20

35

50

65

80

95 110 125

TEMPERATURE (°C)

Figure 11. ADR3412 Start-Up (Turn-On Settle) Time

Figure 14. Line Regulation vs. Temperature

Rev. B | Page 13 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

0

C

= 1.1µF

L

–10

–20

–30

–40

–50

–60

–70

–80

= 0.1µF

IN

1

10µV/DIV

TIME = 1s/DIV

CH1 RMS = 3.14µV

–90

CH1 pk-pk = 18µV

10

100

1k

10k

100k

FREQUENCY (Hz)

Figure 15. ADR3425 Output Voltage Noise (0.1 Hz to 10 Hz)

Figure 18. ADR3425 Ripple Rejection Ratio vs. Frequency

C

R

= C = 0.1µF

L

IN

L

=

∞

1

V

IN

= 2V/DIV

1

100µV/DIV

TIME = 200µs/DIV

2

V

OUT

= 1V/DIV

TIME = 1s/DIV

CH1 pk-pk = 300µV

CH1 RMS = 42.0µV

Figure 16. ADR3425 Output Voltage Noise (10 Hz to 10 kHz)

Figure 19. ADR3425 Start-Up Response

12

10

8

ENABLE

V

C

= 1V/DIV

ENABLE

= 3.0v

IN

= C = 0.1µF

IN

L

R

=

∞

1

6

4

V

= 1V/DIV

OUT

TIME = 200µs/DIV

2

0

0.1

1

10

100

1k

10k

FREQUENCY (Hz)

Figure 17. ADR3425 Output Noise Spectral Density

Figure 20. ADR3425 Restart Response from Shutdown

Rev. B | Page 14 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

0

C

= 1.1µF

L

–10

–20

–30

–40

–50

–60

–70

–80

= 0.1µF

IN

1

10µV/DIV

–90

CH1 pk-pk = 33.4µV

CH1 RMS = 5.68µV

10

100

1k

10k

100k

FREQUENCY (Hz)

Figure 21. ADR3450 Output Voltage Noise (0.1 Hz to 10 Hz)

Figure 24. ADR3450 Ripple Rejection Ratio vs. Frequency

C

R

= 0µF

= 0.1µF

IN

L

=

∞

V

IN

2V/DIV

1

V

OUT

2V/DIV

TIME = 200µs/DIV

100µV/DIV

2

CH1 pk-pk = 446µV

CH1 RMS = 60.3µV

Figure 22. ADR3450 Output Voltage Noise (10 Hz to 10 kHz)

Figure 25. ADR3450 Start-Up Response

12

10

8

ENABLE

V

C

R

= 2V/DIV

ENABLE

= 5.5V

IN

= C = 0.1µF

IN

L

1

=

∞

6

V

= 2V/DIV

OUT

4

TIME = 200µs/DIV

2

0

0.1

1

10

100

1k

10k

FREQUENCY (Hz)

Figure 23. ADR3450 Output Noise Spectral Density

Figure 26. ADR3450 Restart Response from Shutdown

Rev. B | Page 15 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

ENABLE

1V/DIV

ENABLE

2V/DIV

C

= C = 0.1µF

L

= 5V

= 1kΩ

IN

C

= C = 0.1µF

L

= 3V

= 1kΩ

IN

V

R

V

R

IN

L

1

V

= 1V/DIV

V

= 2V/DIV

OUT

2

OUT

2

TIME = 200µs/DIV

Figure 27. ADR3425 Shutdown Response

Figure 30. ADR3450 Shutdown Response

V

= 100mV/DIV

IN

5.5V

5.2V

3.2V

2.7V

C

= C = 0.1µF

L

IN

1

500mV/DIV

C

= C = 0.1µF

L

IN

2

V

= 10mV/DIV

OUT

2

V

= 5mV/DIV

OUT

TIME = 1ms/DIV

1

Figure 28. ADR3425 Line Transient Response

Figure 31. ADR3450 Line Transient Response

I

L

+10mA

–3mA

SOURCING

SINKING

I

+10mA

–3mA

L

SINKING

C

R

=

0.1µF

= 500Ω

IN

C

R

=

0.1µF

= 250Ω

IN

L

5.0V

2.5V

V

= 20mV/DIV

V

= 20mV/DIV

OUT

TIME = 1ms/DIV

Figure 29. ADR3425 Load Transient Response

Figure 32. ADR3450 Load Transient Response

Rev. B | Page 16 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

7

6

5

4

3

2

1

0

100

90

80

70

60

50

40

30

20

10

0

V

= 5.5 V

IN

–40 –25 –10

5

20

35

50

65

80

95 110 125

TEMPERATURE (°C)

RELATIVE SHIFT IN V

OUT

(%)

Figure 33. Supply Current vs. Temperature

Figure 36. Output Voltage Drift Distribution After Reflow (SHR Drift)

2.0

8

T

= +25°C → +150°C → –50°C → +25°C

A

–40°C

+25°C

+125°C

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

7

6

5

4

3

2

1

0

10

20

30

40

50

60

70

80

90

100

ENABLE VOLTAGE (% of V

)

IN

OUTPUT VOLTAGE HYSTERESIS (ppm)

Figure 37. ADR3450 Thermally Induced Output Voltage Hysteresis Distribution

Figure 34. Supply Current vs. ENABLE Pin Voltage

80

10

C

= 0.1µF

= 1.1µF

L

60

40

1

20

0

–20

–40

–60

–80

0.1

0.01

0

200

400

600

800

1000

0.01

0.1

1

10

100

1k

10k

ELAPSED TIME (Hours)

FREQUENCY (Hz)

Figure 35. ADR3450 Output Impedance vs. Frequency

Figure 38. ADR3450 Typical Long-Term Output Voltage Drift

(Four Devices, 1000 Hours)

Rev. B | Page 17 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

TERMINOLOGY

ΔV_{OUT _ HYS}=V_OUT(25°C) −V_{OUT _ TC}[V]

_OUT(25°C) −V_{OUT _ TC}

Dropout Voltage (V_DO

)

Dropout voltage, sometimes referred to as supply voltage

headroom or supply-output voltage differential, is defined as

the minimum voltage differential between the input and output

such that the output voltage is maintained to within 0.1%

accuracy.

V

ΔV_{OUT _ HYS}

=

×10⁶[ppm]

V

_OUT(25°C)

where:

V

_OUT(25°C) is the output voltage at 25°C.

_{OUT_TC}is the output voltage after temperature cycling.

V

_DO= (V_IN− V_OUT)_min| I_L= constant

Long-Term Stability (ΔV_{OUT_LTD}

)

Because the dropout voltage depends upon the current passing

through the device, it is always specified for a given load current.

In series-mode devices, dropout voltage typically increases

proportionally to load current (see Figure 8 and Figure 14).

Long-term stability refers to the shift in output voltage at 50°C

after 1000 hours of operation in a 50°C environment. Ambient

temperature is kept at 50°C to ensure that the temperature

chamber does not switch randomly between heating and cooling,

which can cause instability over the 1000 hour measurement.

This is also expressed as either a shift in voltage or a difference

in ppm from the nominal output.

Temperature Coefficient (TCV_OUT

)

The temperature coefficient relates the change in output voltage

to the change in ambient temperature of the device, as normalized

by the output voltage at 25°C. This parameter is expressed in

ppm/°C and can be determined by the following equation:

ΔV_{OUT _ LTD}= V_OUT(t₁) − V_OUT(t₀) [V]

V_OUT(t₁) −V_OUT(t₀)

max{V_OUT(T₁,T₂,T₃)}− min{V_OUT(T₁,T₂,T₃)}

ΔV_{OUT _ LTD}

=

×10⁶[ppm]

TCV_OUT

=

×

V_OUT(T₂) × (T₃− T₁)

10⁶[ppm/ °C]

V_OUT(t₀)

where:

V_OUT(t₀) is the V_OUTat 50°C at Time 0.

(1)

V_OUT(t₁) is the V_OUTat 50°C after 1000 hours of operation

at 50°C.

where:

V_OUT(T) is the output voltage at Temperature T.

T₁= −40°C.

T₂= +25°C.

T₃= +125°C.

Line Regulation

Line regulation refers to the change in output voltage in response

to a given change in input voltage and is expressed in percent

per volt, ppm per volt, or μV per volt change in input voltage.

This parameter accounts for the effects of self-heating.

This three-point method ensures that TCV_OUTaccurately

portrays the maximum difference between any of the three

temperatures at which the output voltage of the part is

measured.

Load Regulation

Load regulation refers to the change in output voltage in

response to a given change in load current and is expressed in

μV per mA, ppm per mA, or ohms of dc output resistance. This

parameter accounts for the effects of self-heating.

The TCV_OUTfor the ADR3412/ADR3425/ADR3430/ADR3433/

ADR3440/ADR3450 is guaranteed via statistical means. This is

accomplished by recording output voltage data for a large

number of units over temperature, computing TCV_OUTfor each

individual device via Equation 1, then defining the maximum

TCV_OUTlimits as the mean TCV_OUTfor all devices extended by

six standard deviations (6σ).

Solder Heat Resistance (SHR) Drift

SHR drift refers to the permanent shift in output voltage

induced by exposure to reflow soldering, expressed in units of

ppm. This is caused by changes in the stress exhibited upon the

die by the package materials when exposed to high tempera-

tures. This effect is more pronounced in lead-free soldering

processes due to higher reflow temperatures.

Thermally Induced Output Voltage Hysteresis (ΔV_{OUT_HYS}

Thermally induced output voltage hysteresis represents the

change in output voltage after the device is exposed to a

)

specified temperature cycle. This is expressed as either a shift in

voltage or a difference in ppm from the nominal output.

Rev. B | Page 18 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

THEORY OF OPERATION

V

IN

LONG-TERM STABILITY

One of the key parameters of the ADR34xx references is long-

term stability. Regardless of output voltage, internal testing

during development showed a typical drift of approximately

30 ppm after 1000 hours of continuous, nonloaded operation

in a 50°C environment.

BAND GAP

VOLTAGE

REFERENCE

V

BG

ENABLE

V

FORCE

SENSE

OUT

R

FB1

GND FORCE

It is important to understand that long-term stability is not

guaranteed by design and that the output from the device may

shift beyond the typical 30 ppm specification at any time,

especially during the first 200 hours of operation. For systems

that require highly stable output voltages over long periods of

time, the designer should consider burning in the devices prior

to use to minimize the amount of output drift exhibited by the

reference over time. See the AN-713 Application Note, The

Effect of Long-Term Drift on Voltage References, at www.analog.com

for more information regarding the effects of long-term drift

and how it can be minimized.

R

FB2

GND SENSE

Figure 39. Block Diagram

The ADR3412/ADR3425/ADR3430/ADR3433/ADR3440/

ADR3450 use a patented voltage reference architecture to

achieve high accuracy, low temperature coefficient (TC), and

low noise in a CMOS process. Like all band gap references, the

references combine two voltages of opposite TCs to create an

output voltage that is nearly independent of ambient temper-

ature. However, unlike traditional band gap voltage references, the

temperature-independent voltage of the references are arranged

to be the base-emitter voltage, V_BE, of a bipolar transistor at

room temperature rather than the V_BEextrapolated to 0 K (the

V_BEof bipolar transistor at 0 K is approximately V_G0, the band

gap voltage of silicon). A corresponding positive-TC voltage is

then added to the V_BEvoltage to compensate for its negative TC.

POWER DISSIPATION

The ADR34xx voltage references are capable of sourcing up to

10 mA of load current at room temperature across the rated

input voltage range. However, when used in applications subject

to high ambient temperatures, the input voltage and load cur-

rent should be carefully monitored to ensure that the device

does not exceeded its maximum power dissipation rating. The

maximum power dissipation of the device can be calculated via

the following equation:

The key benefit of this technique is that the trimming of the

initial accuracy and TC can be performed without interfering

with one another, thereby increasing overall accuracy across

temperature. Curvature correction techniques further reduce

the temperature variation.

T_J− T_A

P_D=

[W]

θ_JA

where:

The band gap voltage (V_BG) is then buffered and amplified to

produce stable output voltages of 2.5 V and 5.0 V. The output

buffer can source up to 10 mA and sink up to −3 mA of load

current.

P_Dis the device power dissipation.

T_Jis the device junction temperature.

T_Ais the ambient temperature.

θ_JAis the package (junction-to-air) thermal resistance.

The ADR34xx family leverages Analog Devices patented

DigiTrim technology to achieve high initial accuracy and low

TC, and precision layout techniques lead to very low long-term

drift and thermal hysteresis.

Because of this relationship, acceptable load current in high

temperature conditions may be less than the maximum current-

sourcing capability of the device. In no case should the part be

operated outside of its maximum power rating because doing so

can result in premature failure or permanent damage to the device.

Rev. B | Page 19 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

APPLICATIONS INFORMATION

voltages can be sensed accurately. These voltages are fed back

BASIC VOLTAGE REFERENCE CONNECTION

V

into the internal amplifier and used to automatically correct for

the voltage drop across the current-carrying output and ground

lines, resulting in a highly accurate output voltage across the

load. To achieve the best performance, the sense connections

should be connected directly to the point in the load where the

output voltage should be the most accurate. See Figure 41 for an

example application.

OUT

2.5V

V

IN

4

6

V

FORCE

SENSE

2.7V TO

5.5V

IN

ENABLE

OUT

3

5

V

OUT

0.1µF

1µF

0.1µF

ADR34xx

2

1

GND SENSE

GND FORCE

OUTPUT CAPACITOR(S) SHOULD

BE MOUNTED AS CLOSE

Figure 40. Basic Reference Connection

TO V

FORCE PIN AS POSSIBLE.

OUT

The circuit shown in Figure 40 illustrates the basic configuration

for the ADR34xx references. Bypass capacitors should be

connected according to the following guidelines.

0.1µF

6

4

V

FORCE

IN

OUT

3

5

ENABLE

V

SENSE

OUT

INPUT AND OUTPUT CAPACITORS

SENSE CONNECTIONS

SHOULD CONNECT AS

CLOSE TO LOAD

LOAD

A 1 μF to 10 μF electrolytic or ceramic capacitor can be

connected to the input to improve transient response in

applications where the supply voltage may fluctuate. An

additional 0.1 μF ceramic capacitor should be connected

in parallel to reduce high frequency supply noise.

ADR34xx

1µF

0.1µF

DEVICE AS POSSIBLE.

2

1

GND SENSE

GND FORCE

Figure 41. Application Showing Kelvin Connection

A ceramic capacitor of at least a 0.1 μF must be connected to

the output to improve stability and help filter out high fre-

quency noise. An additional 1 μF to 10 μF electrolytic or

ceramic capacitor can be added in parallel to improve transient

performance in response to sudden changes in load current;

however, the designer should keep in mind that doing so

increases the turn-on time of the device.

It is always advantageous to use Kelvin connections whenever

possible. However, in applications where the IR drop is negligi-

ble or an extra set of traces cannot be routed to the load, the

force and sense pins for both V_OUTand GND can simply be tied

together, and the device can be used in the same fashion as a

normal 3-terminal reference (as shown in Figure 40).

Best performance and stability is attained with low ESR (for

example, less than 1 Ω), low inductance ceramic chip-type

output capacitors (X5R, X7R, or similar). If using an electrolytic

capacitor on the output, a 0.1 ꢀF ceramic capacitor should be

placed in parallel to reduce overall ESR on the output.

V_INSLEW RATE CONSIDERATIONS

In applications with slow-rising input voltage signals, the refer-

ence exhibits overshoot or other transient anomalies that appear

on the output. These phenomena also appear during shutdown

as the internal circuitry loses power.

4-WIRE KELVIN CONNECTIONS

To avoid such conditions, ensure that the input voltage wave-

form has both a rising and falling slew rate of at least 0.1 V/ms.

Current flowing through a PCB trace produces an IR voltage

drop, and with longer traces, this drop can reach several

millivolts or more, introducing a considerable error into the

output voltage of the reference. A 1 inch long, 5 millimeter wide

trace of 1 ounce copper has a resistance of approximately

100 mΩ at room temperature; at a load current of 10 mA, this

can introduce a full millivolt of error. In an ideal board layout,

the reference should be mounted as close to the load as possible

to minimize the length of the output traces, and, therefore, the

error introduced by voltage drop. However, in applications

where this is not possible or convenient, force and sense

connections (sometimes referred to as Kelvin sensing

connections) are provided as a means of minimizing the IR

drop and improving accuracy.

SHUTDOWN/ENABLE FEATURE

The ADR34xx references can be switched to a low power shut-

down mode when a voltage of 0.7 V or lower is input to the

ENABLE pin. Likewise, the reference becomes operational for

ENABLE voltages of 0.85 × V_INor higher. During shutdown, the

supply current drops to less than 5 μA, useful in applications that

are sensitive to power consumption.

If using the shutdown feature, ensure that the ENABLE pin

voltage does not fall between 0.7 V and 0.85 × V_INbecause this

causes a large increase in the supply current of the device and

may keep the reference from starting up correctly (see Figure 34).

If not using the shutdown feature, however, the ENABLE pin

can simply be tied to the V_INpin, and the reference remains

operational continuously.

Kelvin connections work by providing a set of high impedance

voltage-sensing lines to the output and ground nodes. Because

very little current flows through these connections, the IR drop

across their traces is negligible, and the output and ground

Rev. B | Page 20 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

SAMPLE APPLICATIONS

Negative Reference

4

6

V

+5V

V

FORCE

SENSE

IN

OUT

R1

10kꢀ

3

5

ENABLE

V

OUT

1µF

0.1µF

Figure 42 shows how to connect the ADR3450 and a standard

CMOS op amp, such as the AD8663, to provide a negative

reference voltage. This configuration provides two main

advantages: first, it only requires two devices and, therefore,

does not require excessive board space; second, and more

importantly, it does not require any external resistors, meaning

that the performance of this circuit does not rely on choosing

expensive parts with low temperature coefficients to ensure

accuracy.

0.1µF

ADR3450

R2

10kꢀ

2

1

GND SENSE

GND FORCE

+15V

–5V

ADA4000-1

R3

5kꢀ

–15V

+VDD

Figure 43. ADR3450 Bipolar Output Reference

1µF

0.1µF

4

3

6

5

AD8663

V

FORCE

SENSE

IN

OUT

Boosted Output Current Reference

–5V

ENABLE

V

Figure 44 shows a configuration for obtaining higher current

drive capability from the ADR34xx references without

sacrificing accuracy. The op amp regulates the current flow

through the MOSFET until V_OUTequals the output voltage of

the reference; current is then drawn directly from V_INinstead of

from the reference itself, allowing increased current drive

capability.

OUT

0.1µF

ADR3450

0.1µF

–VDD

2

1

GND SENSE

GND FORCE

Figure 42. ADR3450 Negative Reference

In this configuration, the V_OUTpins of the reference sit at virtual

ground, and the negative reference voltage and load current are

taken directly from the output of the operational amplifier. Note

that in applications where the negative supply voltage is close to

the reference output voltage, a dual-supply, low offset, rail-to-

rail output amplifier must be used to ensure an accurate output

voltage. The operational amplifier must also be able to source or

sink an appropriate amount of current for the application.

V

IN

+16V

U6

R1

100ꢀ

2N7002

4

3

6

V

FORCE

SENSE

IN

OUT

AD8663

ENABLE

V

5

OUT

V

OUT

1µF 0.1µF

0.1µF

ADR34xx

C

L

0.1µF

R

200ꢀ

L

Bipolar Output Reference

2

1

GND SENSE

GND FORCE

Figure 43 shows a bipolar reference configuration. By connecting

the output of the ADR3450 to the inverting terminal of an

operational amplifier, it is possible to obtain both positive and

negative reference voltages. R1 and R2 must be matched as

closely as possible to ensure minimal difference between the

negative and positive outputs. Resistors with low temperature

coefficients must also be used if the circuit is used in environments

with large temperature swings; otherwise, a voltage difference

develops between the two outputs as the ambient temperature

changes.

Figure 44. Boosted Output Current Reference

Because the current-sourcing capability of this circuit depends

only on the I_Drating of the MOSFET, the output drive capability

can be adjusted to the application simply by choosing an

appropriate MOSFET. In all cases, the V_OUTSENSE pin should

be tied directly to the load device to maintain maximum output

voltage accuracy.

Rev. B | Page 21 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

OUTLINE DIMENSIONS

3.00

2.90

2.80

6

1

5

2

4

3

3.00

2.80

2.60

1.70

1.60

1.50

PIN 1

INDICATOR

0.95 BSC

1.90

BSC

1.30

1.15

0.90

0.20 MAX

0.08 MIN

1.45 MAX

0.95 MIN

0.55

0.45

0.35

0.15 MAX

0.05 MIN

10°

4°

0°

SEATING

PLANE

0.60

BSC

0.50 MAX

0.30 MIN

COMPLIANT TO JEDEC STANDARDS MO-178-AB

Figure 45. 6-Lead Small Outline Transistor Package (SOT-23)

(RJ-6)

Dimensions shown in millimeters

ORDERING GUIDE

Ordering

Quantity Branding

Model¹

Output Voltage (V)

1.200

Temperature Range

−40°C to +125°C

Package Description

6-Lead SOT-23

Package Option

RJ-6

ADR3412ARJZ-R2

ADR3412ARJZ-R7

ADR3420ARJZ-R2

ADR3420ARJZ-R7

ADR3425ARJZ-R2

ADR3425ARJZ-R7

ADR3430ARJZ-R2

ADR3430ARJZ-R7

ADR3433ARJZ-R2

ADR3433ARJZ-R7

ADR3440ARJZ-R2

ADR3440ARJZ-R7

ADR3450ARJZ-R2

ADR3450ARJZ-R7

250

3,000

250

3,000

250

3,000

250

3,000

250

3,000

250

3,000

250

3,000

R2R

R2V

R2X

R2Z

R31

R33

R34

1.200

2.048

RJ-6

2.500

RJ-6

3.000

RJ-6

3.300

RJ-6

4.096

RJ-6

5.000

RJ-6

¹Z = RoHS Compliant Part.

Rev. B | Page 22 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

NOTES

Rev. B | Page 23 of 24

ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450

NOTES

registered trademarks are the property of their respective owners.

D08440-0-6/10(B)

Rev. B | Page 24 of 24


型号：	ADR3425
厂家：	ADI
描述：	Micropower, High Accuracy Voltage References 微功耗，高精度电压基准
文件：	总24页 (文件大小：895K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

ADR3425 [ADI]

相关型号：

SI9130DB

SI9135LG-T1

SI9135LG-T1-E3

SI9135_11

SI9136_11

SI9130CG-T1-E3

SI9130LG-T1-E3

SI9130_11

SI9137

SI9137DB

SI9137LG

SI9122E