Advanced Monolithic Systems AMS9491 1.235V VOLTAGE REFERENCE RoHS compliant FEATURES APPLICATIONS • ±10 mV 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 • 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 long-term 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 Advanced Monolithic Systems, Inc. 4 - Top View www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 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 (25 sec .) 265°C ELECTRICAL CHARACTERISTICS Electrical Characteristics at IR = 100 µA, and TA = +25°C unless otherwise specified. Parameter Conditions AMS9491A 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 (Note 5) Units Typ 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 Min. Operating Current (Note 4) Wide Band Noise AMS9491B Min 8 IR - 100 µA, 10Hz ≤ f ≤ 10kHz 10 20 60 Temperature Coeff. 8 µV 60 50 100 ppm/°C (Note 6) Long Term Stability (Note 5) 20 TA=25°C±.1°C T = 1000 Hr 20 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 SO-8 170°C/W (0.125” leads) 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. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 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 Lower Power Thermometer 0°C - 100°C Thermometer 0°C - 100°C Thermometer * 150 150 M 1.3 TO 1.6V‡ 0-100µA M 8k TO 12k† R1 4k IOUT R2 1k LM334 V- R LM334 AMS9491 R4 220 R2 1k V+ 1.5V (1.3-1.6V)† R3 100 R1 2k IOUT LM334 AMS9491 V+ M 0-50µA R V- * 2N3638 or 2N2907 select for inverse HFE ≅ 5 † Select for operation at 1.3V ‡ IQ ≅ 600µA to 900 µA 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. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 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 150pF 22M 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 Adjustment Procedure VMERCURY + CELL 1.345V TC ADJ 500 ZERO ADJ 100k AMS9491 R2 2k 1% 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 Advanced Monolithic Systems, Inc. J T K S 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 www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS9491 TYPICAL APPLICATIONS (Continued) Precision 1µA to 1mA Current Sources AMS9491 AMS9491 30V C1 150pF R1 100k 2 R1 100k - 7 + - 6 LM312 3 C1 150pF 2 4 IOUT* 7 6 LM312 3 + 4 IOUT* R2 -1.5V TO -27V 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 AMS9491 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 AMS9491 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 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. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723