Datasheet AMS9491 Datasheet (Advanced Monolithic Systems)

http://www.BDTIC.com/AMS

Advanced AMS9491

Monolithic 1.235V VOLTAGE REFERENCE
Systems

RoHS compliant

FEATURES APPLICATIONS

• ±10 mV max. initial tolerance (A grade) • Battery Powered Systems

• Operating Current 10µA to 20mA • Instrumentation

• Low Voltage Reference 1.235 • A/D, D/A Converters

• Max. 0.6Ω Dynamic Impedance (A grade) • Temperature measurement

• Low Temperature Coefficient • Current sources

GENERAL DESCRIPTION

The AMS9491 is a two-terminal micropower band-gap voltage reference diode. It feature a very low dynamic impedance and
good temperature coefficient, operating over a 10µA to 20mA current range. On-chip trimming is used to provide tight voltage
tolerance. Since the AMS9491 is a band-gap reference, uses only transistors and resistors, low noise and good long-term
stability result. Careful design of the AMS9491 has made the device exceptionally tolerant of capacitive loading, making it
easy to use in almost any reference application. The wide dynamic operating range allows its use with widely varying supplies
with excellent regulation. The extremely low power drain of the AMS9491 makes this reference diode useful for micropower
circuitry.
The AMS9491 can be used to make portable meters, regulators or general purpose analog circuitry with battery life
approaching shelf life. Further more, the wide operating current allows it to replace older references with a tight tolerance part.
The AMS9491 is operating over a 0°C to 70°C temperature range and is available in TO-92 and SO-8 packages.

ORDERING INFORMATION:

TOL. PACKAGE TYPE OPERATING

TO-92 8 LEAD SOIC

±10mV AMS9491AN AMS9491AS
±20mV AMS9491BN AMS9491BS

PIN CONNECTIONS

TO-92 8L SOIC

Plastic Package (N) SO Package (S)

13

+

756

• Pagers

TEMPERATURE RANGE

0 to 70° C
0 to 70° C

N/C N/CN/C

Bottom View Top View

Advanced Monolithic Systems, Inc.

12843

N/C N/C N/C

-

AMS9491

http://www.BDTIC.com/AMS

ABSOLUTE MAXIMUM RATINGS (Note 1)

Reverse Current 30mA Soldering information (25 sec .)
Forward Current 10mA
Operating Temperature Range
Storage temperature

0°C to 70°C

-55°C to +150°C

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at IR = 100 µA, and TA = +25°C unless otherwise specified.

Parameter Conditions AMS9491A AMS9491B Units

Reverse Breakdown Voltage
(Note 4)

Reverse Dynamic Impedance
(Note 4)

Reverse Breakdown Voltage
Change with current (Note 4)

Min. Operating Current (Note

4)

- 100 µA

I

R

- 100 µA, f =20Hz

I

R

10µA ≤I
1mA ≤I

≤1mA

R

≤20mA

R

Min Typ Max Min Typ Max

1.215

0.2 0.6 0.2 0.6

2.0

8 10

1.235

1.255

20

20

1.215

2.0

8 10

265°C

1.235

1.255

20

20

V

Ω

mV

µA

Wide Band Noise
(Note 5)

Temperature Coeff.
(Note 6)

Long Term Stability
(Note 5)

IR - 100 µA,
10Hz ≤ f ≤ 10kHz

=25°C±.1°C

T

A

T = 1000 Hr

60 60

50

20 20 ppm

100

ppm/°C

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the

device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical
Characteristics

. The guaranteed specifications apply only for the test conditions listed.

Note 2: Thermal resistance is as follows:

Thermal Resistance TO-92 SO-8

ϕ

(junction to ambient)

JA

170°C/W (0.125” leads) 165°C/W

Note 3: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at T
Note 4: Guaranteed and 100% production tested.
Note 5: Guaranteed but not 100% production tested. These limits are not used to calculate average outgoing quality levels.
Note 6: The average temperature coefficient is defined as the maximum deviation of reference voltage at all measured temperatures between the operating

T

MAX and TMIN

, divided by T

MAX

- T

. The measured temperatures are 0°C, 25°C, 70°C.

MIN

= TJ = 25°C.

A

µV

Advanced Monolithic Systems, Inc.

AMS9491

http://www.BDTIC.com/AMS

TYPICAL APPLICATIONS

Wide Input Micropower Reference Reference from

Range Reference from 9V Battery 1.5V Battery

V

= 2.3V TO 30V

IN

9V

1.5V

LM334

4.3k

OUT

1.24V

AMS9491

0°C - 100°C Thermometer

150

M

0-100

µ

I

OUT

A

LM334

+

V

-

V

R1
4k

R2
1k

R

AMS9491

R3
100

R4
220

1.5V
(1.3-1.6V)†

Calibration

1. Short AMS9491, adjust R3 for I

= temp at

OUT

1µA/°K

2. Remove short, adjust R2 for correct reading in
°C

† IQ at 1.3V ≅ 500 µA
I

at 1.6V ≅ 2.4mA

Q

500k

1.2V

AMS9491

Lower Power Thermometer

*

M

LM334

AMS9491

* 2N3638 or 2N2907 select for inverse H
† Select for operation at 1.3V

≅ 600µA to 900 µA

‡ I

Q

3k

1.2V

AMS9491

0°C - 100°C Thermometer

150

1.3 TO

8k TO
12k†

FE

1.6V‡

≅ 5

M

0-50

µ

A

I

OUT

+

V

LM334

-

V

R1
2k

R2
1k

R

AMS9491

R3
50

R4
100

1.3-1.6V

Calibration

1. Short AMS9491, adjust R3 for I

= temp at

OUT

1.8µA/°K

2. Remove short, adjust R2 for correct reading in
°F

Advanced Monolithic Systems, Inc.

http://www.BDTIC.com/AMS

TYPICAL APPLICATIONS (Continued)

LM334

1.5V†

Calibration

1. Adjust R1 so that V1 = temp at 1mV/°K.

2. Adjust V2 to 273.2mV.

for 1.3V to 1.6V battery voltage = 50µA to 150µA

† I

Q

Micropower Thermocouple Cold Junction Compensator

MERCURY

+

CELL

1.345V

THERMOCOUPLE

Centigrade Thermometer Micropower* 10V Reference

+

V

-

V

1.2k

R1
1k

V1 V2

R

OUTPUT
1mV/° C

2.3k

90k 25k

27k

2.2k

AMS9491

+

LM334

V

5.1k

+

-

1M
1%

AMS9491

COLD JUNCTION

ISO THERMAL

WITH LM334

ZERO ADJ
100k

R2

V

R1

+

METER

-

2k
1%

R

-

TC ADJ
500

AMS9491

I

Q

VIN = 15V

1M

2

7

+

6

8

4

22M

150pF

AMS9491

3

-

*I

≅ 20µA standby current

Q

Adjustment Procedure

1. Adjust TC ADJ pot until voltage across R1 equals Kelvin temperature
multiplied by the thermocouple Seebeck coefficient.

2. Adjust ZERO ADJ pot until voltage across R2 equals the thermocouple
Seebeck coefficient multiplied by 273.2.

Thermocouple Seebeck R1 R2 Voltage Voltage
Type Coefficient (Ω) (Ω) Across R1 Across R2
(mV/ °C) @ 25°C (mV) (mV)

J 52.3 523 1.24k 15.60 14.32
T 42.8 432 1k 12.77 11.78
K 40.8 408 953Ω 12.17 11.17
S 6.4 63.4 150Ω 1.908 1.766

Typical supply current 50µA

10VLM4250C

3.5M

500k

Advanced Monolithic Systems, Inc.

http://www.BDTIC.com/AMS

TYPICAL APPLICATIONS (Continued)

AMS9491

C1

150pF

Precision 1µA to 1mA Current Sources

30V

AMS9491

AMS9491

C1

150pF

7

6

4

R2

-1.5V TO -27V

R1
100k

2

­7

-30V

6

4

R2

*I

OUT

=1.23V/R2

1.5V TO 27V

LM312

3

+

I

*

OUT

R1
100k

2

-

LM312

3

+

I

*

OUT

Advanced Monolithic Systems, Inc.

http://www.BDTIC.com/AMS

TYPICAL PERFORMANCE CHARACTERISTICS

Reverse Characteristics

10

Reverse Characteristics Forward Characteristics

100

AMS9491

1.2

8

6

4

2

0

OUTPUT VOLTAGE CHANGE (mV)

-2

0.01

Reverse Dynamic Impedance

100

)

Ω

10

1

DYNAMIC IMPEDANCE (

0.1

0.01

TA =25° C

0.1 1 10 100

REVERSE CURRENT (mA)

TA =125° C

TA =-55° C

0.1 1 10 100

REVERSE CURRENT (mA)

TA =125° C

TA =25° C

TA =-55° C

A)

µ

10

TA =125° C TA =-55° C

1

REVERSE CURRENT (

0.1

1.260

1.250

1.240

1.230

REFERENCE VOLTAGE (V)

1.220

-55

TA =25° C

0

0.2

0.4 0.6

REVERSE VOLTAGE (V)

Temperature Drift of 3
Representative Units

-35 -15

5

TEMPERATURE (° C)

0.8 1.0 1.2

65 85 105

25 45

IR= 100µA

1.4

125

0.8

TA =25° C

0.4

FORWARD VOLTAGE (V)

0

10k

)

Ω

1k

100

10

1

DYNAMIC IMPEDANCE (

0.1

0.1 1 10 100

0.01
FORWARD CURRENT (mA)

Reverse Dynamic Impedance

TA =25° C

IR= 100µA

10

100

1k

FREQUENCY (Hz)

TA =-55° C

TA =125° C

10k 100k

1M

Filtered Output Noise

70

IR= 100µA

60

V)

µ

50

40

30

20

INTEGRATED NOISE (

10

0

100 1k 10k 100k

SINGLE POLE LOW PASS

100µA

OUTPUT

AMS9491

SHARP CUTOFF
FILTER

CUTOFF FREQUENCY (Hz)

Advanced Monolithic Systems, Inc.

700

600

500

Hz)

√

400
300

NOISE (nV/

200

100

Noise Voltage

0

10

100 1k 10k 100k

FREQUENCY (Hz)

IR= 100µA

2.0

1.5

1.0

0.5
0

~

~

10

VOLTAGE SWING (V)

0

Response Time

INPUT

0

200 400 600

TIME (

OUTPUT

100k

INPUT

OUTPUT

µ

s)

~

~

http://www.BDTIC.com/AMS

PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted.

3 LEAD TO-92 PLASTIC PACKAGE (N)

0.060±0.005

(1.524±0.127)

DIA

0.180±0.005

(4.572±0.127)

0.180±0.005

(4.572±0.127)

0.90

(2.286)

NOM

AMS9491

0.060±0.010

(1.524±0.254)

0.140±0.010

(3.556±0.127)

10°

NOM

N (TO-92 ) AMS DRW# 042391

0.500

(12.70)

MIN

0.050±0.005
(1.270±0.127)

0.050

(1.270)

MAX

0.016±0.003

(0.406±0.076)

UNCONTROLLED
LEAD DIMENSIONS

5° NOM

0.015±0.002

(0.381±0.051)

8 LEAD SOIC PLASTIC PACKAGE (S)

0.189-0.197*

(4.801-5.004)

87 65

0.228-0.244

(5.791-6.197)

0.150-0.157**

(3.810-3.988)

12 34

0.053-0.069

(1.346-1.752)

0.014-0.019

(0.355-0.483)

*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE

Advanced Monolithic Systems, Inc.

0.050

(1.270)

TYP

0.004-0.010

(0.101-0.254)

0.008-0.010

(0.203-0.254)

0.010-0.020
(0.254-0.508)

0.016-0.050

(0.406-1.270)

x 45°

0°-8° TYP

S (SO-8 ) AMS DRW# 042293