Advanced Monolithic Systems AMS9491 1.235V VOLTAGE REFERENCE FEATURES APPLICATIONS • ±10 mV max. initial tolerance (A grade) • Operating Current 10µ µ A to 20mA • Low Voltage Reference 1.235 • Max. 0.6Ω Ω Dynamic Impedance (A grade) • Low Temperature Coefficient • Battery Powered Systems • Instrumentation • A/D, D/A Converters • Temperature measurement • Current sources • Pagers 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 longterm 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 TO-92 ±10mV AMS9491AN ±20mV AMS9491BN OPERATING TEMPERATURE RANGE 8 LEAD SOIC AMS9491AS AMS9491BS 0 to 70° C 0 to 70° C PIN CONNECTIONS TO-92 Plastic Package (N) 3 1 8L SOIC SO Package (S) + 8 1 N/C N/C N/C 7 6 5 2 3 N/C N/C N/C Bottom View 4 - Top View Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS9491 ABSOLUTE MAXIMUM RATINGS (Note 1) Reverse Current Forward Current Operating Temperature Range Storage temperature 30mA 10mA 0°C to 70°C -55°C to +150°C Soldering information TO-92 package: 10 sec. SOIC package: Vapor phase (60 sec) Infrared (15 sec.) 300°C 215°C 220°C ELECTRICAL CHARACTERISTICS Electrical Characteristics at IR = 100 µA, and TA = +25°C unless otherwise specified. Parameter Conditions Reverse Breakdown Voltage (Note 4) IR - 100 µA Reverse Dynamic Impedance (Note 4) IR - 100 µA, f =20Hz Reverse Breakdown Voltage Change with current (Note 4) 10µA ≤IR ≤1mA 1mA ≤IR ≤20mA AMS9491A Max Min Typ Max 1.215 1.235 1.255 1.215 1.235 1.255 V 0.2 0.6 0.2 0.6 Ω 2.0 20 mV 10 20 µA 2.0 20 8 IR - 100 µA, 10Hz ≤ f ≤ 10kHz 10 20 60 Temperature Coeff. (Note 6) Long Term Stability (Note 5) Units Typ Min. Operating Current (Note 4) Wide Band Noise (Note 5) AMS9491B Min 8 50 20 TA=25°C±.1°C T = 1000 Hr µV 60 100 20 ppm/°C ppm 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 ϕ JA (junction to ambient) TO-92 170°C/W (0.125” leads) SO-8 165°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. Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS9491 TYPICAL APPLICATIONS Wide Input Range Reference Micropower Reference from 9V Battery Reference from 1.5V Battery 9V VIN = 2.3V TO 30V 1.5V 500k 3k LM334 1.2V 1.2V 4.3k AMS9491 AMS9491 OUT 1.24V AMS9491 0°°C - 100°°C Thermometer 0°°C - 100°°C Thermometer Lower Power Thermometer * 150 150 M 1.3 TO 1.6V‡ 0-100µA M 8k TO 12k† R1 4k IOUT R2 1k V+ LM334 V- LM334 R AMS9491 LM334 AMS9491 R4 220 R1 2k IOUT R2 1k V+ 1.5V (1.3-1.6V)† R3 100 M 0-50µA V- * 2N3638 or 2N2907 select for inverse HFE ≅ 5 † Select for operation at 1.3V ‡ IQ ≅ 600µA to 900 µA R 1.3-1.6V AMS9491 R3 50 R4 100 Calibration Calibration 1. Short AMS9491, 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 AMS9491, adjust R3 for IOUT = temp at 1.8µA/°K 2. Remove short, adjust R2 for correct reading in °F Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS9491 TYPICAL APPLICATIONS (Continued) Centigrade Thermometer Micropower* 10V Reference IQ VIN = 15V 2.2k + V LM334 V1 R V- 2.3k 1.5V† V2 90k 25k 1M OUTPUT 1mV/° C 2 7 + 6 LM4250C 3 27k 1.2k 10V 8 4 AMS9491 22M 150pF R1 1k 3.5M 500k AMS9491 *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 Micropower Thermocouple Cold Junction Compensator V+ 5.1k LM334 1M 1% R VMERCURY + CELL 1.345V ZERO ADJ 100k AMS9491 R2 2k 1% Adjustment Procedure TC ADJ 500 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 + METER COLD JUNCTION ISO THERMAL WITH LM334 J T K S Seebeck Coefficient (mV/ ° C) R1 (Ω Ω) R2 Voltage Voltage (Ω 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 Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS9491 TYPICAL APPLICATIONS (Continued) Precision 1µ µ A to 1mA Current Sources AMS9491 AMS9491 30V C1 150pF R1 100k 2 R1 100k - + 2 7 - 6 LM312 3 C1 150pF 4 IOUT* 7 6 LM312 3 IOUT* R2 -1.5V TO -27V + 4 R2 1.5V TO 27V -30V *IOUT =1.23V/R2 Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS9491 TYPICAL PERFORMANCE CHARACTERISTICS Reverse Characteristics TA =125° C 6 4 TA =25° C 2 TA =-55° C 0 10 T A =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 SHARP CUTOFF FILTER 1.5 VOLTAGE SWING (V) AMS9491 NOISE (nV/√Hz) 100µA 20 0 100 10 10k 100k 1k FREQUENCY (Hz) 1M IR= 100 µA 40 10 1 2.0 600 SINGLE POLE LOW PASS OUTPUT 30 10 Response Time 700 IR= 100 µA 50 100 Noise Voltage Filtered Output Noise 70 60 T A =25° C I R= 100 µA 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 I R= 100 µA 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 T A =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 1.0 100k 0.5 0 OUTPUT ~ ~ ~ ~ 10 INPUT 100 0 1k 10k 100k CUTOFF FREQUENCY (Hz) OUTPUT INPUT 0 10 100 1k 10k FREQUENCY (Hz) 100k 0 200 400 TIME (µs) 600 Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS9491 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. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140