AMS AMS385

AMS285/385-2.5
FEATURES
APPLICATIONS
• ±20 mV (±0.8%) max. initial tolerance (A grade)
• Operating Current 20µA to 20mA
• Low Voltage Reference 2.5V
• Max. 0.6Ω Dynamic Impedance (A grade)
• Low Temperature Coefficient
• 1.2V Device and Adjustable Device also available
AMS285-1.2 and AMS285 series, respectively
AMS385-1.2 and AMS385 series.
• Battery Powered Systems
• Instrumentation
• A/D, D/A Converters
• Temperature measurement
• Current sources
• Notebook/Personal Computer
• Monitors/ VCR/ TV
• 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 20µA 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.
±20mV
±38mV
±75mV
±20mV
±38mV
±75mV
PACKAGE TYPE
TO-92
AMS285-2.5AN
AMS285-2.5BN
AMS285-2.5CN
AMS385-2.5AN
AMS385-2.5BN
AMS385-2.5CN
8 LEAD SOIC
AMS285-2.5AS
AMS285-2.5BS
AMS285-2.5CS
AMS385-2.5AS
AMS385-2.5BS
AMS385-2.5CS
OPERATING
SOT-89
AMS285-2.5AL
AMS285-2.5BL
AMS285-2.5CL
AMS385-2.5AL
AMS385-2.5BL
AMS385-2.5CL
TEMPERATURE RANGE
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-40 to 85° C
-40 to 85° C
-40 to 85° C
0 to 70° C
0 to 70° C
0 to 70° C
AMS285/385-2.5
ABSOLUTE MAXIMUM RATINGS
Reverse Current
Forward Current
Operating Temperature Range
AMS285-2.5
AMS385-2.5
30mA
10mA
Storage temperature
Soldering information (25 sec)
-55°C to +150°C
265°C
-40°C to 85°C
0°C to 70°C
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at IR = 100 µA, and TA = +25°C unless otherwise specified.
Parameter
Reverse Breakdown
Voltage (Note 4)
Reverse Dynamic
Impedance (Note 4)
Reverse Breakdown
Voltage Change with
current (Note 4)
Conditions
Min
AMS285A-2.5
Typ
Max
2.480
2.500
2.520
IR - 100 µA, f =20Hz
0.2
0.60
10µA ≤IR ≤1mA
1mA ≤IR ≤20mA
1.0
10
(Note 5)
2.462
2.500
2.538
AMS285C-2.5
Min
Typ
Max
2.425
2.500
2.575
Units
V
IR - 100 µA
Min. Operating
Current (Note 4)
Wide Band Noise
AMS285B-2.5
Typ
Max
Min
Temperature Coeff.
18
20
13
Ω
1
1.0
10
12
IR - 100 µA,
10Hz ≤ f ≤ 10kHz
1
20
30
13
120
120
120
25
50
100
20
20
20
2.0
20
mV
20
30
µA
µA
µV
150
ppm/°C
(Note 6)
Long Term Stability
(Note 5)
TA=25°C±.1°C
T = 1000 Hr
ppm
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at IR = 100 µA, and TA = +25°C unless otherwise specified.
Parameter
Reverse Breakdown
Voltage (Note 4)
Reverse Dynamic
Impedance (Note 4)
Reverse Breakdown
Voltage Change with
Current (Note 4)
Conditions
(Note 5)
AMS385A-2.5
Typ
Max
2.480
2.500
2.520
IR - 100 µA, f =20Hz
0.2
0.60
10µA ≤IR ≤1mA
1mA ≤IR ≤20mA
1.0
10
Min
AMS385B-2.5
Typ
Max
2.462
2.500
2.538
AMS385C-2.5
Min
Typ
Max
2.425
2.500
2.575
Units
V
IR - 100 µA
Min. Operating
Current (Note 4)
Wide Band Noise
Min
Temperature Coeff.
18
20
13
Ω
1
2.0
20
12
IR - 100 µA,
10Hz ≤ f ≤ 10kHz
1
20
30
13
120
120
120
25
50
100
20
20
20
2.0
20
mV
20
30
µA
µA
µV
150
ppm/°C
(Note 6)
Long Term Stability
(Note 5)
TA=25°C±.1°C
T = 1000 Hr
2
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ppm
AMS285/385-2.5
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, Tj max is:
AMS285
AMS385
+125°C
+100°C
Thermal Resistance
ϕ JA (junction to ambient)
TO-92
170°C/W (0.125” leads)
SO-8
SOT-89
165°C/W
160°C/W
Note 3: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at TA = TJ = 25°C.
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
TMAX and TMIN, divided by TMAX - TMIN. The measured temperatures are 0°C, 25°C, 70°C and 85°C.
PIN CONNECTIONS
TO-92
Plastic Package (N)
3
2
8L SOIC
SO Package (S)
N/C N/C N/C
7
6
5
+
8
1
1
2
3
N/C N/C N/C
Bottom View
SOT-89
(L)
4
-
3
2
1
N/C
+
-
Top View
Top View
TYPICAL APPLICATIONS
Wide Input
Range Reference
Micropower Reference
from 9V Battery
9V
VIN = 3.7V TO 30V
200k
LM334
2.5V
3.3k
AMS385-2.5
OUT
2.5V
AMS385-2.5
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AMS285/385-2.5
TYPICAL APPLICATIONS (Continued)
0°C - 100°C Thermometer
0°C - 100°C Thermometer
1k
150
0-100µA M
M
0-50µA
R1
8k
IOUT
R2
1k
V+
R
LM334
R2
1k
V+
3V
R
LM334
AMS385-2.5
V-
R1
4k
IOUT
AMS385-2.5
V-
R3
100
3V
R3
50
R4
220
R4
100
Calibration
Calibration
1. Short AMS385-2.5, adjust R3 for IOUT = temp at 1µA/°K
2. Remove short, adjust R2 for correct reading in °C
1. Short AMS385-2.5, adjust R3 for IOUT = temp at 1.8µA/°K
2. Remove short, adjust R2 for correct reading in °F
Micropower* 5V Regulator
Micropower* 10V Reference
IQ
IQ
VIN ≥ 5.2V
V+
47k
R
LM334
VIN = 15V
500k
2
2N2905
V-
2.2k
3
6
LM4250C
+
7
3
VO = 5V
IL ≤ 100mA
6
LM4250C
2
7
+
8 1N457
4
150pF
1N457
10V
8
4
22M
150pF
100k
+
4.7µF
TANTALUM
500k
AMS385-2.5
10M
2k
1.5M
100k
AMS385-2.5
*IQ ≅ 20µA standby current
*IQ ≅ 40µA
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TYPICAL APPLICATIONS (Continued)
Micropower Thermocouple Cold Junction Compensator
V+
18k
LM334
1M
1%
2k
1%
R
Adjustment Procedure
V-
TC ADJ
500
ZERO ADJ
100k
3V +
LITHIUM
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.
AMS385-2.5
R2
R1
Thermocouple
Type
+
THERMOCOUPLE
+
R1
(Ω)
R2
Voltage
Voltage
(Ω) Across R1
Across R2
@ 25°C (mV)
(mV)
52.3
42.8
40.8
6.4
523
432
412
63.4
1.24k
1k
953Ω
150Ω
J
T
K
S
METER
-
Seebeck
Coefficient
(mV/ °C)
COLD JUNCTION
ISO THERMAL
WITH LM334
Typical supply current 50µA
Precision 1µA to 1mA Current Sources
AMS385-2.5
AMS385-2.5
30V
C1
150pF
R1
68k
R1
68k
2
-
+
2
-
7
3
4
+
IOUT*
IOUT*
7
6
LM312
6
LM312
3
C1
150pF
1.5V TO 27V
R2
-1.5V TO -27V
-30V
*IOUT =2.5V/R2
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4
R2
15.60
12.77
12.17
1.908
14.32
11.78
11.17
1.766
AMS285/385-2.5
TYPICAL PERFORMANCE CHARACTERISTICS
Reverse Characteristics
8
TA =25° C
4
TA =-55° C
0
10
TA =125° C
TA =-55° C
1
0.1
1
10
REVERSE CURRENT (mA)
0.5 1.0
1.5 2.0
2.5
REVERSE VOLTAGE (V)
3.0
0.01
TA =-55° C
1
TA =25° C
0.1
100
Reverse Dynamic Impedance
2.510
2.500
2.490
2.480
2.470
2.460
2.450
-55 -35 -15 5 25 45 65 85 105 125
TEMPERATURE (° C)
0
100
100
10
1
10
100
IR= 100µA
AMS385-2.5
SHARP CUTOFF
FILTER
OUTPUT
VOLTAGE SWING (V)
NOISE (nV/√Hz)
OUTPUT
1000
800
600
400
200
0
1k
10k
CUTOFF FREQUENCY (Hz)
100k
1M
Response Time
1200
100µA
10k
100k
1k
FREQUENCY (Hz)
3.0
SINGLE POLE LOW PASS
40
20
1k
0.1
1400
100
60
TA =25° C
IR= 100µA
Noise Voltage
Filtered Output Noise
80
IR= 100µA
2.520
120
0.1
1
10
100
FORWARD CURRENT (mA)
10k
DYNAMIC IMPEDANCE (Ω)
REFERENCE VOLTAGE (V)
TA =125° C
IR= 100µA
TA =25° C
0.4
Temperature Drift
100
0.1
1
10
REVERSE CURRENT (mA)
0.8
TA =125° C
2.530
0.01
TA =-55° C
0
0
100
Reverse Dynamic Impedance
10
1.2
TA =25° C
0.1
-4
1000
DYNAMIC IMPEDANCE (Ω)
1.6
FORWARD VOLTAGE (V)
TA =125° C
12
0.01
INTEGRATED NOISE ( µV)
Forward Characteristics
100
REVERSE CURRENT (µA)
OUTPUT VOLTAGE CHANGE (mV)
Reverse Characteristics
16
2.0
INPUT
100k
OUTPUT
1.0
0
~
~
~
~
10
INPUT
0
10
100
1k
10k
FREQUENCY (Hz)
100k
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0
200
400
TIME (µs)
600
AMS285/385-2.5
PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted.
3 LEAD TO-92 PLASTIC PACKAGE (N)
0.180±0.005
(4.572±0.127)
0.060±0.005
(1.524±0.127)
DIA
0.060±0.010
(1.524±0.254)
0.90
(2.286)
NOM
0.180±0.005
(4.572±0.127)
0.140±0.010
(3.556±0.127)
5° NOM
0.500
(12.70)
MIN
0.050
(1.270)
MAX
UNCONTROLLED
LEAD DIMENSIONS
0.015±0.002
(0.381±0.051)
0.016±0.003
(0.406±0.076)
0.050±0.005
(1.270±0.127)
10°
NOM
N (TO-92 ) AMS DRW# 042391
8 LEAD SOIC PLASTIC PACKAGE (S)
0.189-0.197*
(4.801-5.004)
8
7
6
5
0.228-0.244
(5.791-6.197)
0.150-0.157**
(3.810-3.988)
1
2
3
4
0.010-0.020 x 45°
(0.254-0.508)
0.053-0.069
(1.346-1.752)
0.004-0.010
(0.101-0.254)
0.014-0.019
(0.355-0.483)
0.008-0.010
(0.203-0.254)
0.050
(1.270)
TYP
0°-8° TYP
0.016-0.050
(0.406-1.270)
*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
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S (SO-8 ) AMS DRW# 042293
AMS285/385-2.5
PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted (Continued).
SOT-89 PLASTIC PACKAGE (L)
0.173-0.181
(4.40-4.60)
0.055-0.063
(1.40-1.60)
0.014-0.017
(0.35-0.44)
0.064-0.072
(1.62-1.83)
0.155-0.167
(3.94-4.25)
0.084-0.090
(2.13-2.29)
0.090-0.102
(2.29-2.60)
0.035-0.047
(0.89-1.20)
0.059
(1.50)
BSC
0.014-0.019
(0.36-0.48)
0.017-0.022
(0.44-0.56)
L (SOT-89 ) AMS DRW# 042392
0.118
(3.00)
BSC
8
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