Advanced Monolithic Systems
FEATURES
• ±4 mV (±0.3%) max. initial tolerance (A grade) • Operating Current 10µ A 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.
AMS285-1.2/AMS385-1.2
MICROPOWER VOLTAGE REFERENCE DIODE
APPLICATIONS
• 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 TO-92 AMS285-1.2AN AMS285-1.2BN AMS285-1.2CN AMS385-1.2AN AMS385-1.2BN AMS385-1.2CN PACKAGE TYPE 8 LEAD SOIC AMS285-1.2AS AMS285-1.2BS AMS285-1.2CS AMS385-1.2AS AMS385-1.2BS AMS385-1.2CS SOT-89 AMS285-1.2AL AMS285-1.2BL AMS285-1.2CL AMS385-1.2AL AMS385-1.2BL AMS385-1.2CL 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
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-1.2/AMS385-1.2
ABSOLUTE MAXIMUM RATINGS
Reverse Current Forward Current Operating Temperature Range AMS285-1.2 AMS385-1.2 30mA 10mA -40°C to 85°C 0°C to 70°C Storage temperature Soldering information TO-92 package: 10 sec. SOIC package: Vapor phase (60 sec) Infrared (15 sec.) SOT-89 package: 10 sec. -55°C to +150°C 260°C 215°C 220°C 265°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) Min. Operating Current (Note 4) Wide Band Noise (Note 5) Temperature Coeff. (Note 6) Long Term Stability (Note 5) TA=25°C±.1°C T = 1000 Hr IR - 100 µA, 10Hz ≤ f ≤ 10kHz
Conditions
IR - 100 µA IR - 100 µA, f =20Hz 10µ A ≤IR ≤1mA 1mA ≤IR ≤20mA
Min
AMS285A-1.2 Typ Max
1.235 0.2 1.0 10 8 10 20 1.239 0.60
Min
1.223
AMS285B-1.2 Typ Max
1.235 1 1.0 10 8 10 20 1.247
Min
AMS285C-1.2 Typ Max
1.235 1 1.0 20 8 15 25 1.260
Units
V Ω mV
1.231
1.205
µA µA µV
60
60
60
25
50
100
150
ppm/°C
20
20
20
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) Min. Operating Current (Note 4) Wide Band Noise (Note 5) Temperature Coeff. (Note 6) Long Term Stability (Note 5) TA=25°C±.1°C T = 1000 Hr IR - 100 µA, 10Hz ≤ f ≤ 10kHz
Conditions
IR - 100 µA IR - 100 µA, f =20Hz 10µ A ≤IR ≤1mA 1mA ≤IR ≤20mA
Min
AMS385A-1.2 Typ Max
1.235 0.2 1.0 10 8 10 20 1.239 0.60
Min
AMS385B-1.2 Typ Max
1.235 1 1.0 20 8 10 20 1.247
Min
AMS385C-1.2 Typ Max
1.235 1 1.0 20 8 15 25 1.260
Units
V Ω mV
1.231
1.223
1.205
µA µA µV
60
60
60
25
50
100
150
ppm/°C
20
20
20
ppm
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
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
TO-92
170°C/W (0.125” leads)
SO-8
165°C/W
SOT-89
160°C/W
ϕ JA (junction to ambient)
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) 8L SOIC SO Package (S)
+ 8 N/C N/C N/C 7 6 5
SOT-89 (L)
3
2
1
3 1 2 3 N/C N/C N/C 4 N/C
2 +
1 -
Bottom View
Top View
Top View
TYPICAL APPLICATIONS
Wide Input Range Reference Micropower Reference from 9V Battery Reference from 1.5V Battery
VIN = 2.3V TO 30V
9V
1.5V
500k LM334 1.2V 4.3k AMS385-1.2 OUT 1.24V AMS385-1.2
3k 1.2V AMS385-1.2
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-1.2/AMS385-1.2
TYPICAL APPLICATIONS (Continued)
0° C - 100° C Thermometer Lower Power Thermometer 0° C - 100° C Thermometer
*
150
M 1.3 TO 1.6V‡
150
0-100µA M IOUT R1 4k R2 1k R AMS385-1.2 R3 100 R4 220
LM334 AMS385-1.2
8k TO 12k†
0-50µA IOUT
M R1 2k R2 1k R AMS385-1.2 R3 50 R4 100
V+ LM334 V-
1.5V (1.3-1.6V)†
V+ LM334 V-
1.3-1.6V
* 2N3638 or 2N2907 select for inverse HFE ≅ 5 † Select for operation at 1.3V ‡ IQ ≅ 600µ A to 900 µ A
Calibration 1. Short AMS385-1.2, adjust R3 for IOUT = temp at 1µ A/°K 2. Remove short, adjust R2 for correct reading in °C † IQ at 1.3V ≅ 500 µ A IQ at 1.6V ≅ 2.4mA
Calibration 1. Short AMS385-1.2, adjust R3 for IOUT = temp at 1.8µ A/°K 2. Remove short, adjust R2 for correct reading in °F
Centigrade Thermometer
Micropower* 10V Reference
IQ VIN = 15V 2.2k V
+
LM334 V1.5V†
R 2.3k
V1
V2
90k
25k
1M 2 + 7 LM4250C 3 8 4 22M 150pF 3.5M 6 10V
OUTPUT 1mV/° C
1.2k
27k
AMS385-1.2
R1 1k AMS385-1.2
500k
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 = 50µ A to 150µ A
*IQ ≅ 20µ A standby current
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-1.2/AMS385-1.2
TYPICAL APPLICATIONS (Continued)
Micropower Thermocouple Cold Junction Compensator
V+
LM334 2k 1%
5.1k
1M 1% V-
R
Adjustment Procedure
TC ADJ 500
MERCURY + CELL 1.345V AMS385-1.2
ZERO ADJ 100k
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 Type Seebeck Coefficient (mV/ ° C) 52.3 42.8 40.8 6.4 R1 (Ω ) R2 Voltage Voltage (Ω ) Across R1 Across R2 @ 25° C (mV) (mV) 1.24k 1k 953Ω 150Ω 15.60 12.77 12.17 1.908 14.32 11.78 11.17 1.766
R2
R1
+ THERMOCOUPLE + COLD JUNCTION ISO THERMAL WITH LM334 METER
J T K S
523 432 408 63.4
Typical supply current 50µ A
Precision 1µ A to 1mA Current Sources
AMS385-1.2 AMS385-1.2 30V
C1 150pF R1 100k 2 LM312 3 IOUT* -1.5V TO -27V -30V + 4 IOUT* R2 1.5V TO 27V R2 C1 150pF 2 LM312 6 3 + 4 7 6
R1 100k
7
*IOUT =1.23V/R2
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-1.2/AMS385-1.2
TYPICAL PERFORMANCE CHARACTERISTICS
Reverse Characteristics OUTPUT VOLTAGE CHANGE (mV) 10 8 6 4 2 0 -2 0.01 0.1 1 10 REVERSE CURRENT (mA) 100
TA =25° C TA =-55° C
Reverse Characteristics 100 REVERSE CURRENT (µ A) FORWARD VOLTAGE (V) 1.2
Forward Characteristics
TA =125° C
TA =-55° C
10
T A =125° C TA =-55° C
0.8
1
TA =25° C
0.4
T A =25° C TA =125° C
0.1 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 REVERSE VOLTAGE (V) Temperature Drift of 3 Representative Units 1.260 DYNAMIC IMPEDANCE (Ω ) REFERENCE VOLTAGE (V)
I R= 100 µA
0 0.01 0.1 1 10 100 FORWARD CURRENT (mA)
Reverse Dynamic Impedance 100 DYNAMIC IMPEDANCE (Ω )
Reverse Dynamic Impedance 10k 1k 100 10
T A =25° C I R= 100 µA
1.250
10
TA =125° C
1.240
1
TA =-55° C
TA =25° C
1.230
1 0.1
1.220 -55 -35 -15 5 25 45 65 85 105 125 TEMPERATURE (° C) Noise Voltage 700
0.1 0.01 0.1 1 10 REVERSE CURRENT (mA) 100
10
100
10k 100k 1k FREQUENCY (Hz)
1M
Filtered Output Noise 70
IR= 100 µA
Response Time 2.0
IR= 100 µA
INTEGRATED NOISE ( µ V)
60 50 40 30 20 10 0 100
AMS385-1.2 100 µA
VOLTAGE SWING (V)
SINGLE POLE LOW PASS
600 NOISE (nV/√Hz) 500 400 300 200 100 0
1.5 1.0 0.5 0
OUTPUT INPUT 100k OUTPUT
OUTPUT
~ ~
INPUT
~ ~
10
SHARP CUTOFF FILTER
0 10 100 1k 10k FREQUENCY (Hz) 100k 0 200 400 TIME ( µs) 600
1k 10k 100k CUTOFF FREQUENCY (Hz)
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-1.2/AMS385-1.2
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) 0.060±0.010 (1.524±0.254) 0.140±0.010 (3.556±0.127)
0.180±0.005 (4.572±0.127)
0.90 (2.286) NOM
5° NOM 0.500 (12.70) MIN
10° NOM
0.050 (1.270) MAX
UNCONTROLLED LEAD DIMENSIONS
0.050±0.005 (1.270±0.127)
0.016±0.003 (0.406±0.076)
0.015±0.002 (0.381±0.051)
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
0.053-0.069 (1.346-1.752) 0.004-0.010 (0.101-0.254) 0.008-0.010 (0.203-0.254)
0.010-0.020 x 45° (0.254-0.508) 0°-8° TYP
0.014-0.019 (0.355-0.483)
0.050 (1.270) 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. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
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) 0.064-0.072 (1.62-1.83)
0.055-0.063 (1.40-1.60) 0.014-0.017 (0.35-0.44)
0.155-0.167 (3.94-4.25) 0.090-0.102 (2.29-2.60) 0.084-0.090 (2.13-2.29)
0.035-0.047 (0.89-1.20) 0.059 (1.50) BSC 0.118 (3.00) BSC 0.014-0.019 (0.36-0.48) 0.017-0.022 (0.44-0.56)
L (SOT-89 ) AMS DRW# 042392
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140