Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
Advanced
AMS285-2.5/AMS385-2.5
Monolithic
MICROPOWER VOLTAGE REFERENCE DIODE
Systems
FEATURES
APPLICATIONS
20 mV (
0.8%) max. initial tolerance (A grade)
Battery Powered Systems
Operating Current 20
A to 20mA
Instrumentation
Low Voltage Reference 2.5V
A/D, D/A Converters
Max. 0.6
Dynamic Impedance (A grade)
Temperature measurement
Low Temperature Coefficient
Current sources
1.2V Device and Adjustable Device also available
Notebook/Personal Computer
AMS285-1.2 and AMS285 series, respectively
Monitors/ VCR/ TV
AMS385-1.2 and AMS385 series.
Pagers
GENERAL DESCRIPTION
The AMS285-2.5/AMS385-2.5 are two-terminal micropower band-gap voltage reference diodes. They feature a very low
dynamic impedance and good temperature coefficient, operating over a 20
A to 20mA current range. On-chip trimming is
used to provide tight voltage tolerance. Since the AMS285-2.5/AMS385-2.5 is a band-gap reference, uses only transistors and
resistors, low noise and good long term stability result. Careful design of the AMS285-2.5/AMS385-2.5 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
AMS285-2.5/AMS385-2.5 makes these reference diodes useful for micropower circuitry. These voltage references 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 AMS285-2.5 is operational in the full industrial temperature range of -40
C to 85
C while AMS385-2.5 is operating
over a 0
C to 70
C temperature range. The AMS285-2.5/AMS385-2.5 are available in TO-92, SO-8 and SOT-89 packages.
ORDERING INFORMATION:
TOL.
PACKAGE TYPE
OPERATING
TO-92
8 LEAD SOIC
SOT-89
TEMPERATURE RANGE
20mV AMS285-2.5AN
AMS285-2.5AS
AMS285-2.5AL
-40 to 85
C
38mV AMS285-2.5BN
AMS285-2.5BS
AMS285-2.5BL
-40 to 85
C
75mV AMS285-2.5CN
AMS285-2.5CS
AMS285-2.5CL
-40 to 85
C
20mV AMS385-2.5AN
AMS385-2.5AS
AMS385-2.5AL
0 to 70
C
38mV AMS385-2.5BN
AMS385-2.5BS
AMS385-2.5BL
0 to 70
C
75mV AMS385-2.5CN
AMS385-2.5CS
AMS385-2.5CL
0 to 70
C
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
ABSOLUTE MAXIMUM RATINGS
Reverse Current
30mA
Storage temperature
-55
C to +150
C
Forward Current
10mA
Soldering information
Operating Temperature Range
TO-92 package: 10 sec.
260
C
AMS285-2.5
-40
C to 85
C
SOIC package: Vapor phase (60 sec)
215
C
AMS385-2.5
0
C to 70
C
Infrared (15 sec.)
220
C
SOT-89 package: 10 sec.
265
C
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I
R
= 100
A, and T
A
= +25C unless otherwise specified.
Parameter
Conditions
AMS285A-2.5
Min Typ Max
AMS285B-2.5
Min Typ Max
AMS285C-2.5
Min Typ Max
Units
Reverse Breakdown
Voltage (Note 4)
I
R
- 100
A
2.480
2.500
2.520
2.462
2.500
2.538
2.425
2.500
2.575
V
Reverse Dynamic
Impedance (Note 4)
I
R
- 100
A, f =20Hz
0.2
0.60
1
1
Reverse Breakdown
Voltage Change with
current (Note 4)
10
A
I
R
1mA
1mA
I
R
20mA
1.0
10
1.0
10
2.0
20
mV
Min. Operating
Current (Note 4)
12
18
20
13
20
30
13
20
30
A
A
Wide Band Noise
(Note 5)
I
R
- 100
A,
10Hz
f
10kHz
120
120
120
V
Temperature Coeff.
(Note 6)
25
50
100
150
ppm/C
Long Term Stability
(Note 5)
T
A
=25C.1C
T = 1000 Hr
20
20
20
ppm
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I
R
= 100
A, and T
A
= +25C unless otherwise specified.
Parameter
Conditions
AMS385A-2.5
Min Typ Max
AMS385B-2.5
Min Typ Max
AMS385C-2.5
Min Typ Max
Units
Reverse Breakdown
Voltage (Note 4)
I
R
- 100
A
2.480
2.500
2.520
2.462
2.500
2.538
2.425
2.500
2.575
V
Reverse Dynamic
Impedance (Note 4)
I
R
- 100
A, f =20Hz
0.2
0.60
1
1
Reverse Breakdown
Voltage Change with
Current (Note 4)
10
A
I
R
1mA
1mA
I
R
20mA
1.0
10
2.0
20
2.0
20
mV
Min. Operating
Current (Note 4)
12
18
20
13
20
30
13
20
30
A
A
Wide Band Noise
(Note 5)
I
R
- 100
A,
10Hz
f
10kHz
120
120
120
V
Temperature Coeff.
(Note 6)
25
50
100
150
ppm/C
Long Term Stability
(Note 5)
T
A
=25C.1C
T = 1000 Hr
20
20
20
ppm
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
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:
For elevated temperature operation, T
j
max is:
AMS285
+125C
AMS385
+100C
Thermal Resistance
TO-92
SO-8
SOT-89
JA
(junction to ambient)
170C/W (0.125" leads)
165C/W
160C/W
Note 3:
Parameters identified with boldface type apply at temperature extremes. All other numbers apply at T
A
= T
J
= 25C.
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
T
MIN
, divided by T
MAX
- T
MIN
. The measured temperatures are 0
C, 25
C, 70
C and 85
C.
PIN CONNECTIONS
TO-92
8L SOIC
SOT-89
Plastic Package (N)
SO Package (S)
(L)
1
2
3
1
2
8
4
3
7
5
6
N/C
N/C
N/C
N/C N/C
N/C
+
-
N/C
-
+
1
2
3
Bottom View
Top View
Top View
TYPICAL APPLICATIONS
Wide Input
Micropower Reference
Range Reference
from 9V Battery
3.3k
LM334
OUT
2.5V
AMS385-2.5
V
IN
= 3.7V TO 30V
AMS385-2.5
2.5V
200k
9V
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
TYPICAL APPLICATIONS
(Continued)
0
C - 100
C Thermometer
0
C - 100
C Thermometer
AMS385-2.5
1k
R1
8k
R2
1k
R3
100
R4
220
3V
R
V
-
V
+
LM334
M
0-100
A
I
OUT
Calibration
1. Short AMS385-2.5, adjust R3 for I
OUT
= temp at 1
A/
K
2. Remove short, adjust R2 for correct reading in
C
AMS385-2.5
150
R1
4k
R2
1k
R3
50
R4
100
3V
R
V
-
V
+
LM334
M
0-50
A
I
OUT
Calibration
1. Short AMS385-2.5, adjust R3 for I
OUT
= temp at 1.8
A/
K
2. Remove short, adjust R2 for correct reading in
F
Micropower* 5V Regulator
Micropower* 10V Reference
150pF
AMS385-2.5
100k
10M
2.2k
7
4
6
2
3
-
+
V
IN
5.2V
I
Q
V
O
= 5V
I
L
100mA
LM4250C
8
R
V
-
V
+
LM334
2k
100k
47k
2N2905
1N457
1N457
+
4.7
F
TANTALUM
*I
Q
40
A
150pF
AMS385-2.5
1.5M
500k
22M
500k
7
4
6
3
2
-
+
V
IN
= 15V
I
Q
10V
LM4250C
8
*I
Q
20
A standby current
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
TYPICAL APPLICATIONS
(Continued)
Micropower Thermocouple Cold Junction Compensator
+
LM334
AMS385-2.5
R1
R2
ZERO ADJ
100k
1M
1%
18k
2k
1%
TC ADJ
500
METER
3V
LITHIUM
+
-
V
+
V
-
R
THERMOCOUPLE
+
-
COLD JUNCTION
ISO THERMAL
WITH LM334
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 (
) (
) 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 40.8 412 953
12.17 11.17
S 6.4 63.4 150
1.908 1.766
Typical supply current 50
A
Precision 1
A to 1mA Current Sources
7
4
3
2
+
-
LM312
6
AMS385-2.5
R2
R1
68k
-30V
-1.5V TO -27V
C1
150pF
I
OUT
*
*I
OUT
=2.5V/R2
7
4
3
2
+
-
LM312
6
R2
R1
68k
30V
1.5V TO 27V
C1
150pF
I
OUT
*
AMS385-2.5
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
TYPICAL PERFORMANCE CHARACTERISTICS
-4
4
8
16
0.1
1
10
100
Reverse Characteristics
0
OUTPUT VOLTAGE CHANGE (mV)
T
A
=25 C
0.1
1000
0.1
1
10
100
Reverse Dynamic Impedance
1
100
DYNAMIC IMPEDANCE (
)
0.01
0
0.4
1.6
0.1
1
10
100
0.8
0.01
REVERSE CURRENT (mA)
REVERSE CURRENT (mA)
0
0.5
1.0
1.5
2.0
2.5
0.1
100
10
3.0
REVERSE VOLTAGE (V)
REVERSE CURRENT (
A)
1
Reverse Characteristics
Forward Characteristics
FORWARD CURRENT (mA)
FORWARD VOLTAGE (V)
10
100
1k
10k
100k
0.1
1k
10
Reverse Dynamic Impedance
1M
FREQUENCY (Hz)
DYNAMIC IMPEDANCE (
)
1
10k
100
-55
5
25 45 65 85 105
2.530
2.490
125
REFERENCE VOLTAGE (V)
Temperature Drift
0
10
0
1.0
3.0
0
200
400
600
TIME (
s)
Response Time
VOLTAGE SWING (V)
2.0
~
~
~
~
0
400
800
1200
1400
100
1k
10k
100k
Noise Voltage
200
1000
NOISE (nV/
Hz)
I
R
= 100
A
10
FREQUENCY (Hz)
600
100
1k
10k
100k
CUTOFF FREQUENCY (Hz)
INTEGRATED NOISE (
V
)
0
20
40
60
80
100
120
TEMPERATURE ( C)
2.510
2.470
2.460
-35 -15
I
R
= 100
A
T
A
=-55 C
T
A
=125 C
T
A
=125 C
T
A
=-55 C
T
A
=25 C
T
A
=-55 C
T
A
=25 C
T
A
=125 C
T
A
=25 C
I
R
= 100
A
T
A
=-55 C
T
A
=25 C
T
A
=125 C
I
R
= 100
A
100
A
OUTPUT
AMS385-2.5
OUTPUT
100k
INPUT
OUTPUT
INPUT
SINGLE POLE LOW PASS
SHARP CUTOFF
FILTER
Filtered Output Noise
0.01
10
12
1.2
2.520
2.500
2.480
2.450
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
PACKAGE DIMENSIONS
inches (millimeters) unless otherwise noted.
3 LEAD TO-92 PLASTIC PACKAGE (N)
8 LEAD SOIC PLASTIC PACKAGE (S)
0.1400.010
(3.5560.127)
0.0600.010
(1.5240.254)
0.0150.002
(0.3810.051)
0.0160.003
(0.4060.076)
0.0500.005
(1.2700.127)
0.0600.005
(1.5240.127)
DIA
0.1800.005
(4.5720.127)
0.1800.005
(4.5720.127)
0.050
(1.270)
MAX
0.500
(12.70)
MIN
UNCONTROLLED
LEAD DIMENSIONS
10
NOM
5 NOM
N (TO-92 ) AMS DRW# 042391
0.90
(2.286)
NOM
0-8 TYP
0.010-0.020
(0.254-0.508)
S (SO-8 ) AMS DRW# 042293
x 45
0.016-0.050
(0.406-1.270)
0.008-0.010
(0.203-0.254)
0.004-0.010
(0.101-0.254)
0.014-0.019
(0.355-0.483)
0.053-0.069
(1.346-1.752)
0.050
(1.270)
TYP
0.150-0.157**
(3.810-3.988)
0.228-0.244
(5.791-6.197)
0.189-0.197*
(4.801-5.004)
*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
1
2
3
4
8
7
6
5
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
PACKAGE DIMENSIONS
inches (millimeters) unless otherwise noted (Continued).
SOT-89 PLASTIC PACKAGE (L)
0.090-0.102
(2.29-2.60)
0.173-0.181
(4.40-4.60)
0.064-0.072
(1.62-1.83)
0.155-0.167
(3.94-4.25)
0.059
(1.50)
BSC
0.035-0.047
(0.89-1.20)
L (SOT-89 ) AMS DRW# 042392
0.118
(3.00)
BSC
0.014-0.019
(0.36-0.48)
0.017-0.022
(0.44-0.56)
0.084-0.090
(2.13-2.29)
0.055-0.063
(1.40-1.60)
0.014-0.017
(0.35-0.44)
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