Datasheet AS2431DR5VST, AS2431DR5VSB, AS2431DR5VSA, AS2431DR5VS7, AS2431DR5VS13 Datasheet (ASTEC)

1

ASTEC Semiconductor

AS2431

Precision Adjustable Shunt Reference

Features

¥

Temperature-compensated: 15 ppm/¡C

¥

Trimmed bandgap reference

¥

Internal amplifier with 100 mA capability

¥

Multiple temperature ranges

¥

Low frequency dynamic output impedance:
< 450 m½

¥

Low output noise

Description

The AS2431 is a three-terminal adjustable shunt regulator providing a highly accu­rate bandgap reference. The adjustable shunt regulator is ideal for a wide variety
of linear applications that can be implemented using external components to
obtain adjustable currents and voltages.

In the standard shunt configuration, the combination of low temperature coeffi­cient (TC), sharp turn-on characteristics, low output impedance and program­mable output voltage make this precision reference an excellent error amplifier.

The AS2431 is a direct replacement for the AS431 in low voltage, low current appli­cations. It is also available in the very small footprint SOT-23.

SEMICONDUCTOR

Pin Configuration Ñ Top view

CATHODE

TO-92 (LP) SOIC (D)

ANODE

REFERENCE

CATHODE

REFERENCE

ANODE

ANODE

N/C

CATHODE

ANODE

ANODE

N/C

SOT-89 (S)

SOT-23/3L (VS)

ANODE

REFERENCE

1

2

3

4

8

7

6

5

CATHODE

REFERENCE

ANODE

Circuit Type:
Precision Adjustable
Shunt Regulator

Temperature Range:
A = 0°C to 70°C
B = 0°C to 105°C
C = –40°C to +85°C
D = –55°C to +125°C

Bandgap Tolerance:
2
1
R4
R5
R25

= ±2%
= ±1%
= ±0.4%
= ±0.5%
= ±0.25%

AS2431 A 2 D 7

Packaging Option:
A
B
T
7
13

Package Style:
D
LP
S
VS

= Ammo Pack
= Bulk
= Tube
= Tape and Reel (7" Reel Dia)
= Tape and Reel (13" Reel Dia)

= SOIC
= TO-92
= SOT-89
= SOT-23/3L

Ordering Information

2

ASTEC Semiconductor

AS2431 Precision Adjustable Shunt Reference

Functional Block Diagram

Absolute Maximum Ratings

Parameter Symbol Rating Units

Cathode-Anode Reverse Breakdown V

KA

18 V

Anode-Cathode Forward Current I

AK

1 A

Operating Cathode Current I

KA

100 mA

Reference Input Current I

REF

1 mA

Continuous Power Dissipation at 25¡C P

D

TO-92 775 mW

8L SOIC 750 mW

SOT-89 1000 mW

SOT-23/3L 200 mW

Junction Temperature T

J

150 ¡C

Storage Temperature T

STG

Ð65 to 150 ¡C

Lead Temp, Soldering 10 Seconds T

L

300 ¡C

Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a
stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sec­tions of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.

Ð

+

REFERENCE

(R)

ANODE (A)

CATHODE (K)

2.5 V

Recommended Conditions

Parameter Symbol Rating Unit

Cathode Voltage V

KA

V

REF

to 18 V

Cathode Current I

K

10 mA

Typical Thermal Resistances

Package θ

JA

θ

JC

Typical Derating

TO-92 160¡C/W 80¡C/W 6.3 mW/¡C

SOIC 175¡C/W 45¡C/W 5.7 mW/¡C

SOT-89 110¡C/W 8¡C/W 9.1 mW/¡C

SOT-23/3L 575¡C/W 150¡C/W 1.7 mW/¡C

3

ASTEC Semiconductor

AS2431Precision Adjustable Shunt Reference

Electrical Characteristics

Electrical Characteristics are guaranteed over full junction temperature range (0 to 105¡C). Ambient temperature must be derated based
on power dissipation and package thermal characteristics. The conditions are: VKA= V

REF

and IK= 10 mA unless otherwise stated.

Test AS2431 (0.25%) AS2431 (0.5%) Test

Parameter Symbol Condition Min. Typ. Max. Min. Typ. Max. Unit Circuit

Reference Voltage V

REF

TA= 25¡C 2.494 2.500 2.506 2.490 2.500 2.515 V 1

Over temp. 2.480 2.518 2.480 2.530 V 1

ÆV

REF

with Temp* TC 0.04 0.06 0.04 0.06 mV/¡C 1

Ratio of Change in ÆV

REFVREF

to 10 V Ð2.7 Ð1.01 Ð2.7 Ð1.01

V

REF

to Cathode

ÆV

K

mV/V 2

Voltage 10 V to 18 V Ð2.0 Ð0.4 0.3 Ð2.0 Ð0.4 0.3

Reference Input I

REF

0.7 4 0.7 4 µA 2

Current

I

REF

Temp Deviation ÆI

REF

Over temp. 0.4 1.2 0.4 1.2 µA 2

Min IKfor Regulation I

K(min)

0.4 1 0.4 1 mA 1

Off State Leakage I

K(off)

V

REF

= 0 V, 0.04 500 0.04 500 nA 3

VKA= 18 V

Dynamic Output Z

KA

f ² 1 kHz 0.45 1 0.45 1 ½ 1

Impedance IK= 1 to 150 mA

Test AS2431 (1.0%) AS2431 (2.0%) Test

Parameter Symbol Condition Min. Typ. Max. Min. Typ. Max. Unit Circuit

Reference Voltage V

REF

TA= 25¡C 2.470 2.495 2.520 2.440 2.495 2.550 V 1

Over temp. 2.450 2.540 2.415 2.580 V 1

ÆV

REF

with Temp* TC 0.04 0.06 0.04 0.06 mV/¡C 1

Ratio of Change in ÆV

REFVREF

to 10 V Ð2.7 Ð1.01 Ð2.7 Ð1.01

V

REF

to Cathode

ÆV

K

mV/V 2

Voltage 10 V to 18 V Ð2.0 Ð0.4 0.3 Ð2.0 Ð0.4 0.3

Reference Input I

REF

0.7 4 0.7 4 µA 2

Current

I

REF

Temp Deviation ÆI

REF

Over temp. 0.4 1.2 0.4 1.2 µA 2

Min IKfor Regulation I

K(min)

0.4 1 0.4 1 mA 1

Off State Leakage I

K(off)

V

REF

= 0 V, 0.04 500 0.04 500 nA 3

VKA= 18 V

Dynamic Output Z

KA

f ² 1 kHz 0.45 1 0.45 1 ½ 1

Impedance IK= 1 to 150 mA

*Calculating Average Temperature Coefficient (TC). Refer to following page.

4

ASTEC Semiconductor

AS2431 Precision Adjustable Shunt Reference

Test Circuits

Figure 1a. Test Circuit 1 Figure 1b. Test Circuit 2 Figure 1c. Test Circuit 3

Average Temperature Coefficient

0

–10

–20

0.55000

0 0

0 15

0.07 mV/°C

0.003%/°C
27 ppm/°C

30 45 60 75 90 105

ppm

mV

%

∆V

REF

∆T

Temperature (°C)

• TC in mV/°C =

• TC in %/°C =

∆T

A

∆T

A

X 100

∆V

REF

(mV)

V

REF

at 25°C

∆V

REF

• TC in ppm/°C =
∆T

A

X 10

6

V

REF

at 25°C

∆V

REF

R

1

R

2

I

K

V

IN

V

KA

(V

REF

)

I

REF

I

REF

I

K

V

IN

VKA = V

REF

I

K (OFF)

V

IN

VKA

5

ASTEC Semiconductor

AS2431Precision Adjustable Shunt Reference

Typical Performance

Figure 2

Figure 4

Figure 3

Figure 5

I

K

– Cathode Current (µA)

900

700
600

500
400
300
200

100

0
–100
–200

800

–1.0 0 1.0

V

KA

– Cathode Voltage (V)

2.0 3.0

Low Current Operating Characteristics

VKA = V

REF

Temperature Range: –55 to 125°C

125°C

25°C

–55°C

I

K

– Cathode Current (mA)

150
125
100

75
50
25

0

–25
–50
–75

–100

–2 –1 0 1 2 3

V

KA

– Cathode Voltage (V)

High Current Operating Characteristics

VKA = V

REF

Temperature Range: –55 to 125°C

I

Z

off – Off State Cathode Current (nA)

100

10

1

0.1

0.01

–60 –30 0 30

T

A

– Ambient Temperature (°C)

60 90 120

Off State Leakage

VKA = 18 V
V

REF

= 0 V

V

REF

– Reference Voltage (V)

3.53

2.52

2.51

2.50

2.49

2.48

2.47

2.46

2.45

–60 –30 0 30

TA – Ambient Temperature (°C)

60 90 120

VKA = V

REF

IK = 10 mA

Reference Voltage vs Ambient Temperature

V

REF

= 2.500 V at 25°C

6

ASTEC Semiconductor

AS2431 Precision Adjustable Shunt Reference

Typical Performance Curves

Figure 6

Figure 8

Figure 7

Figure 9

3.0

2.5

2.0

1.5

1.0

0.5

0

–60 –30 0 30 60 90 120

I

REF

– Reference Input Current (µA)

TA – Ambient Temperature (°C)

Reference Input Current

R1 = 10 kΩ
R2 = ∞
I

K

=10 mA

0

–5

–10

–15

–20

–25

0 3 6 9

V

KA

– Cathode Voltage (V)

12 15 18

∆

V

REF

– Change in Reference Voltage (mV)

IK = 10 mA

Temperature Range: –55 to 125°C

–30°C

25°C

75°C

125°C

Reference Voltage Line Regulation

70

60

50

40

30

20

10

0

10 100 1 k

f – Frequency (Hz)

10 k 100 k

Noise Voltage nV/√Hz

VKA = V

REF

IK = 10 mA
T

A

= 25°C

Noise Voltage

Z

KA

– Dynamic Impedance (Ω)

0.150

0.125

0.100

0.075

0.050

0.025

0.0

–60 –30 0 30

TA – Free Air Temperature

60 90 120

VKA = V

REF

IKA = 1 to 100 mA
f ≤ 1 kHz

Low Frequency Dynamic Output Impedance

7

ASTEC Semiconductor

AS2431Precision Adjustable Shunt Reference

Typical Performance Curves

Figure 10

Figure 11

100

10

1.0

Z

KA

– Dynamic Impedance (Ω)

0.1

0.01
1 k 10 k 100 k

f – Frequency (Hz)

1 M 10 M

TA = 25°C
I

K

= 1 to 100 mA

Dynamic Output Impedance

70

60

50

40

30

20

10

0

1 k 10 k 100 k 1 M 10 M

f – Frequency (Hz)

230 Ω

I

K

A

V

– Small Signal Voltage Gain (dB)

Temperature Range: –55 to 125°C

I

K

= 10 mA

OUT

GND

15 k

8.25 k

9 µF

Small Signal Voltage Gain vs. Frequency

8

ASTEC Semiconductor

AS2431 Precision Adjustable Shunt Reference

Typical Performance Curves

Figure 12

Figure 13

6

5

4

3

Input and Output Votages (V)

2

1

0

–1

0 1 2 3 4 5 6 7

t – Time (ms)

8 9 10 11 12

Input

Output

Pulse Response

INPUT
MONITOR

220 Ω

50 Ω

OUT

GND

fP = 100 kHz

100

90
80
70
60

50
40
30
20

10

0

10

0101102103

CL – Load Capacitance (pF)

10

4105106107

150 Ω

C

L

10 K

I

K

A

C

D

B

T

A

= 25°C

Stability Boundary Conditions

Stability
Region

I

K

– Cathode Current (mA)

A: VKA = V

REF

B: VKA = 5 V at IK = 10 mA
C: V

KA

= 10 V at IK = 10 mA

D: V

KA

= 15 V at IK = 10 mA