AMS285-1.2

Advanced
Monolithic
Systems
AMS285-1.2/AMS385-1.2
MICROPOWER VOLTAGE REFERENCE DIODE
RoHS compliant
FEATURES
APPLICATIONS
• ±4 mV (±0.3%) max. initial tolerance (A grade)
• Operating Current 10µA to 20mA
• Low Voltage Reference 1.235
• Max. 0.6Ω Dynamic Impedance (A grade)
• Low Temperature Coefficient
• 2.5V Device and Adjustable Device also available
AMS285-2.5 and AMS285 series, respectively
AMS385-2.5 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 AMS285-1.2/AMS385-1.2 are two-terminal micropower band-gap voltage reference diodes. They 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 AMS285-1.2/AMS385-1.2 is a band-gap reference, uses only transistors and
resistors, low noise and good long-term stability result. Careful design of the AMS285-1.2/AMS385-1.2 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
AMS285-1.2/AMS385-1.2 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 AMS285-1.2 is operational in the full industrial temperature range of -40°C to 85°C while AMS385-1.2 is operating over
a 0°C to 70°C temperature range. The AMS285-1.2/AMS385-1.2 are available in TO-92, SO-8 and SOT-89 packages.
ORDERING INFORMATION:
TOL.
±4mV
±12mV
±25mV
±4mV
±12mV
±25mV
PACKAGE TYPE
TO-92
AMS285-1.2AN
AMS285-1.2BN
AMS285-1.2CN
AMS385-1.2AN
AMS385-1.2BN
AMS385-1.2CN
8 LEAD SOIC
AMS285-1.2AS
AMS285-1.2BS
AMS285-1.2CS
AMS385-1.2AS
AMS385-1.2BS
AMS385-1.2CS
Advanced Monolithic Systems, Inc.
SOT-89
AMS285-1.2AL
AMS285-1.2BL
AMS285-1.2CL
AMS385-1.2AL
AMS385-1.2BL
AMS385-1.2CL
www.advanced-monolithic.com
OPERATING
TEMPERATURE RANGE
-40 to 85° C
-40 to 85° C
-40 to 85° C
0 to 70° C
0 to 70° C
0 to 70° C
Phone (925) 443-0722
Fax (925) 443-0723
AMS285-1.2/AMS385-1.2
ABSOLUTE MAXIMUM RATINGS
Reverse Current
Forward Current
Operating Temperature Range
AMS285-1.2
AMS385-1.2
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-1.2
Typ
Max
1.231
1.235
1.239
IR - 100 µA, f =20Hz
0.2
0.60
10µA ≤IR ≤1mA
1mA ≤IR ≤20mA
1.0
10
(Note 5)
1.223
1.235
1.247
AMS285C-1.2
Min
Typ
Max
1.205
1.235
1.260
Units
V
IR - 100 µA
Min. Operating
Current (Note 4)
Wide Band Noise
AMS285B-1.2
Typ
Max
Min
8
IR - 100 µA,
10Hz ≤ f ≤ 10kHz
Temperature Coeff.
1
1.0
10
10
20
8
Ω
1
10
20
8
60
60
60
25
50
100
20
20
20
1.0
20
mV
15
25
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
Min
1.231
1.235
1.239
IR - 100 µA, f =20Hz
0.2
0.60
10µA ≤IR ≤1mA
1mA ≤IR ≤20mA
1.0
10
(Note 5)
Min
AMS385B-1.2
Typ
Max
1.223
1.235
1.247
AMS385C-1.2
Min
Typ
Max
1.205
1.235
1.260
Units
V
IR - 100 µA
Min. Operating
Current (Note 4)
Wide Band Noise
AMS385A-1.2
Typ
Max
8
IR - 100 µA,
10Hz ≤ f ≤ 10kHz
Temperature Coeff.
1
1.0
20
10
20
8
Ω
1
10
20
8
60
60
60
25
50
100
20
20
20
1.0
20
mV
15
25
µA
µA
µV
150
ppm/°C
(Note 6)
Long Term Stability
(Note 5)
TA=25°C±.1°C
T = 1000 Hr
Advanced Monolithic Systems, Inc.
www.advanced-monolithic.com
Phone (925) 443-0722
Fax (925) 443-0723
ppm
AMS285-1.2/AMS385-1.2
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, 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
Micropower Reference
from 9V Battery
Reference from
1.5V Battery
TYPICAL APPLICATIONS
Wide Input
Range Reference
1.5V
9V
VIN = 2.3V TO 30V
3k
500k
LM334
1.2V
1.2V
AMS385-1.2
AMS385-1.2
4.3k
OUT
1.24V
AMS385-1.2
Advanced Monolithic Systems, Inc.
www.advanced-monolithic.com
Phone (925) 443-0722
Fax (925) 443-0723
AMS285-1.2/AMS385-1.2
TYPICAL APPLICATIONS (Continued)
Lower Power Thermometer
0°C - 100°C Thermometer
0°C - 100°C Thermometer
*
150
150
M
1.3 TO
1.6V‡
0-100µA M
R1
4k
IOUT
R2
1k
LM334
R
R2
1k
V+
1.5V
(1.3-1.6V)†
R
LM334
AMS385-1.2
V-
R1
2k
IOUT
LM334
AMS385-1.2
V+
M
0-50µA
8k TO
12k†
V-
R3
100
AMS385-1.2
R3
50
* 2N3638 or 2N2907 select for inverse HFE ≅ 5
† Select for operation at 1.3V
‡ IQ ≅ 600µA to 900 µA
R4
220
1.3-1.6V
R4
100
Calibration
Calibration
1. Short AMS385-1.2, adjust R3 for IOUT = temp at
1µA/°K
2. Remove short, adjust R2 for correct reading in
°C
† IQ at 1.3V ≅ 500 µA
IQ at 1.6V ≅ 2.4mA
1. Short AMS385-1.2, adjust R3 for IOUT = temp at
1.8µA/°K
2. Remove short, adjust R2 for correct reading in
°F
Centigrade Thermometer
Micropower* 10V Reference
IQ
VIN = 15V
2.2k
+
V
LM334
V1
R
V1.5V†
2.3k
V2
90k
25k
1M
OUTPUT
1mV/° C
2
7
+
6
LM4250C
3
1.2k
27k
4
AMS385-1.2
10V
8
22M
150pF
R1
1k
3.5M
500k
AMS385-1.2
*IQ ≅ 20µA standby current
Calibration
1. Adjust R1 so that V1 = temp at 1mV/°K.
2. Adjust V2 to 273.2mV.
† IQ for 1.3V to 1.6V battery voltage = 50µA to 150µA
Advanced Monolithic Systems, Inc.
www.advanced-monolithic.com
Phone (925) 443-0722
Fax (925) 443-0723
AMS285-1.2/AMS385-1.2
TYPICAL APPLICATIONS (Continued)
Micropower Thermocouple Cold Junction Compensator
V+
5.1k
LM334
1M
1%
2k
1%
R
Adjustment Procedure
VMERCURY
+
CELL
1.345V
TC ADJ
500
ZERO ADJ
100k
AMS385-1.2
R2
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.
R1
Thermocouple
Type
+
THERMOCOUPLE
+
J
T
K
S
METER
COLD JUNCTION
ISO THERMAL
WITH LM334
Seebeck
Coefficient
(mV/ °C)
R1
(Ω)
R2
Voltage
Voltage
(Ω) Across R1
Across R2
@ 25°C (mV)
(mV)
52.3
42.8
40.8
6.4
523
432
408
63.4
1.24k
1k
953Ω
150Ω
15.60
12.77
12.17
1.908
14.32
11.78
11.17
1.766
Typical supply current 50µA
Precision 1µA to 1mA Current Sources
AMS385-1.2
30V
AMS385-1.2
C1
150pF
R1
100k
R1
100k
2
-
-
+
7
6
LM312
7
6
LM312
3
C1
150pF
2
3
+
4
4
IOUT*
R2
1.5V TO 27V
IOUT*
R2
-1.5V TO -27V
-30V
*IOUT =1.23V/R2
Advanced Monolithic Systems, Inc.
www.advanced-monolithic.com
Phone (925) 443-0722
Fax (925) 443-0723
AMS285-1.2/AMS385-1.2
TYPICAL PERFORMANCE CHARACTERISTICS
Reverse Characteristics
TA =125° C
6
4
TA =25° C
2
TA =-55° C
0
10
TA =125° C
TA =-55° C
1
TA =25° C
0.1
-2
0.1
1
10
REVERSE CURRENT (mA)
TA =25° C
TA =-55° C
Reverse Dynamic Impedance
1.250
1.240
1.230
1.220
100
AMS385-1.2
SHARP CUTOFF
FILTER
1.5
VOLTAGE SWING (V)
NOISE (nV/√Hz)
100µA
20
0
100
10
10k
100k
1k
FREQUENCY (Hz)
1M
IR= 100µA
40
10
1
2.0
600
SINGLE POLE LOW PASS
OUTPUT
30
10
Response Time
700
IR= 100µA
50
100
Noise Voltage
Filtered Output Noise
70
60
TA =25° C
IR= 100µA
1k
0.1
-55 -35 -15 5 25 45 65 85 105 125
TEMPERATURE (° C)
100
0.1
1
10
100
FORWARD CURRENT (mA)
10k
IR= 100µA
0.1
0.1
1
10
REVERSE CURRENT (mA)
TA =125° C
0.01
DYNAMIC IMPEDANCE (Ω)
REFERENCE VOLTAGE (V)
TA =125° C
0.01
TA =25° C
0.4
0.2 0.4 0.6 0.8 1.0 1.2 1.4
REVERSE VOLTAGE (V)
1.260
1
0.8
Temperature Drift of 3
Representative Units
100
10
TA =-55° C
0
0
100
Reverse Dynamic Impedance
DYNAMIC IMPEDANCE (Ω)
1.2
FORWARD VOLTAGE (V)
8
0.01
INTEGRATED NOISE ( µV)
Forward Characteristics
100
REVERSE CURRENT (µA)
OUTPUT VOLTAGE CHANGE (mV)
Reverse Characteristics
10
500
400
300
200
100k
0.5
0
OUTPUT
~
~
~
~
10
INPUT
100
0
1k
10k
CUTOFF FREQUENCY (Hz)
OUTPUT
INPUT
1.0
100k
Advanced Monolithic Systems, Inc.
0
10
100
1k
10k
FREQUENCY (Hz)
www.advanced-monolithic.com
100k
0
Phone (925) 443-0722
200
400
TIME (µs)
600
Fax (925) 443-0723
AMS285-1.2/AMS385-1.2
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)
S (SO-8 ) AMS DRW# 042293
*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.
www.advanced-monolithic.com
Phone (925) 443-0722
Fax (925) 443-0723
AMS285-1.2/AMS385-1.2
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
Advanced Monolithic Systems, Inc.
www.advanced-monolithic.com
Phone (925) 443-0722
Fax (925) 443-0723