LM285H-1.2

LM185-1.2/LM285-1.2/LM385-1.2 Micropower Voltage Reference Diode January 2000 LM185-1.2/LM285-1.2/LM385-1.2 Micropower Voltage Reference Diode General Description The LM185-1.2/LM285-1.2/LM385-1.2 are micropower 2-terminal band-gap voltage regulator diodes. Operating over a 10 µA to 20 mA current range, they feature exceptionally low dynamic impedance and good temperature stability. On-chip trimming is used to provide tight voltage tolerance. Since the LM185-1.2 band-gap reference uses only transistors and resistors, low noise and good long term stability result. Careful design of the LM185-1.2 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 LM185-1.2 makes it useful for micropower circuitry. This voltage reference can be used to make portable meters, regulators or general purpose analog circuitry with battery life approaching shelf life. Further, the wide operating current allows it to replace older references with a tighter tolerance part. The LM185-1.2 is rated for operation over a −55˚C to 125˚C temperature range while the LM285-1.2 is rated −40˚C to 85˚C and the LM385-1.2 0˚C to 70˚C. The LM185-1.2/ LM285-1.2 are available in a hermetic TO-46 package and the LM285-1.2/LM385-1.2 are also available in a low-cost TO-92 molded package, as well as SO and SOT-23. The LM185-1.2 is also available in a hermetic leadless chip carrier package. Features n n n n n n n ± 4 mV ( ± 0.3%) max. initial tolerance (A grade) Operating current of 10 µA to 20 mA 0.6Ω max dynamic impedance (A grade) Low temperature coefficient Low voltage reference — 1.235V 2.5V device and adjustable device also available LM185-2.5 series and LM185 series, respectively Connection Diagrams T0-92 Plastic Package (Z) SOT23 DS005518-33 * Pin 3 is attached to the Die Attach Pad (DAP) and should be connected to Pin 2 or left floating. DS005518-10 Order Number LM385M3-1.2 See NS Package Number MA03B Bottom View Order Number LM285Z-1.2, LM285BXZ-1.2, LM285BYZ-1.2 LM385Z-1.2, LM385BZ-1.2 LM385BXZ-1.2 or LM385BYZ-1.2 See NS Package Number Z03A © 2000 National Semiconductor Corporation DS005518 www.national.com LM185-1.2/LM285-1.2/LM385-1.2 Connection Diagrams (Continued) SO Package DS005518-9 Order Number LM285M-1.2, LM285BXM-1.2, LM285BYM-1.2 LM385M-1.2, LM385BM-1.2 LM385BXM-1.2 or LM385BYM-1.2 See NS Package Number M08A TO-46 Metal Can Package (H) DS005518-6 Bottom View Order Number LM185H-1.2, LM185H-1.2/883, LM185BXH-1.2, LM185BYH-1.2 LM285H-1.2 or LM285BXH-1.2 See NS Package Number H02A www.national.com 2 LM185-1.2/LM285-1.2/LM385-1.2 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. (Note 2) Reverse Current Forward Current Operating Temperature Range (Note 3) LM185-1.2 LM285-1.2 LM385-1.2 30 mA 10 mA −55˚C to +125˚C −40˚C to +85˚C 0˚C to 70˚C Storage Temperature −55˚C to +150˚C Soldering Information TO-92 package: 10 sec. 260˚C TO-46 package:10 sec. 300˚C SO and SOT Pkg. Vapor phase (60 sec.) 215˚C Infrared (15 sec.) 220˚C See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” for other methods of soldering surface mount devices. Electrical Characteristics (Note 4) LM185-1.2 LM185BX-1.2 LM185BY-1.2 LM285-1.2 Parameter Conditions Typ LM285BX-1.2 LM285BY-1.2 Tested Limit (Notes 5, 8) Reverse Breakdown Voltage Minimum Operating Current Reverse Breakdown Voltage Change with Current Reverse Dynamic Impedance Wideband Noise (rms) Long Term Stability Average Temperature Coefficient (Note 7) IR = 100 µA, 10 Hz ≤ f ≤ 10 kHz IR = 100 µA, T = 1000 Hr, TA = 25˚C ± 0.1˚C IR = 100 µA X Suffix Y Suffix All Others 30 50 150 30 50 150 150 ppm/˚C ppm/˚C ppm/˚C (Max) 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: Refer to RETS185H-1.2 for military specifications. Note 3: For elevated temperature operation, Tj max is: LM185 LM285 LM385 150˚C 125˚C 100˚C LM385B-1.2 LM385BX-1.2 LM385BY-1.2 LM385-1.2 Units (Limit) Tested Limit (Note 5) 1.223 1.247 Design Limit (Note 6) Tested Limit (Note 5) 1.205 1.260 20 1.5 25 15 10 1 20 20 15 1.5 25 Design Limit (Note 6) V(Min) V(Max) µA (Max) mV (Max) mV (Max) Ω µV ppm Design Limit (Note 6) TA = 25˚C, 10 µA ≤ IR ≤ 20 mA 1.235 8 1.223 1.247 10 1 10 20 1.5 20 15 1 20 LM385M3-1.2 10 µA ≤ IR ≤ 1 mA 1 mA ≤ IR ≤ 20 mA IR = 100 µA, f = 20 Hz 1 60 20 Thermal Resistance θJA (junction to ambient) θJC (junction to case) TO-92 180˚C/W (0.4" leads) 170˚C/W (0.125" leads) N/A TO-46 440˚C/W 80˚C/W SO-8 165˚C/W N/A SOT23 283˚C/W N/A Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at TA = TJ = 25˚C. 3 www.national.com LM185-1.2/LM285-1.2/LM385-1.2 Electrical Characteristics (Note 4) Note 5: Guaranteed and 100% production tested. (Continued) Note 6: Guaranteed, but not 100% production tested. These limits are not used to calculate average outgoing quality levels. Note 7: 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 −55˚C, −40˚C, 0˚C, 25˚C, 70˚C, 85˚C, 125˚C. Note 8: A military RETS electrical specification is available on request. Typical Performance Characteristics Reverse Characteristics Reverse Characteristics Forward Characteristics DS005518-13 DS005518-14 DS005518-15 Temperature Drift of 3 Representative Units Reverse Dynamic Impedance Reverse Dynamic Impedance DS005518-17 DS005518-16 DS005518-18 Noise Voltage Filtered Output Noise Response Time DS005518-19 DS005518-20 DS005518-21 www.national.com 4 LM185-1.2/LM285-1.2/LM385-1.2 Typical Applications Wide Input Range Reference Micropower Reference from 9V Battery Reference from 1.5V Battery DS005518-22 DS005518-23 DS005518-8 Micropower* 5V Regulator Micropower* 10V Reference DS005518-25 *IQ ≅ 20 µA standby current DS005518-24 *IQ ≅ 30 µA Precision 1 µA to 1 mA Current Sources DS005518-27 DS005518-26 5 www.national.com LM185-1.2/LM285-1.2/LM385-1.2 Typical Applications (Continued) METER THERMOMETERS 0˚C−100˚C Thermometer Lower Power Thermometer DS005518-29 *2N3638 or 2N2907 select for inverse HFE ≅ 5 †Select for operation at 1.3V ‡ IQ ≅ 600 µA to 900 µA DS005518-28 Calibration 1. Short LM385-1.2, adjust R3 for IOUT = temp at 1 µA/˚K 2. Remove short, adjust R2 for correct reading in centigrade †IQ at 1.3V ≅ 500 µA IQ at 1.6V ≅ 2.4 mA 0˚F−50˚F Thermometer Micropower Thermocouple Cold Junction Compensator DS005518-30 Calibration 1. Short LM385-1.2, adjust R3 for IOUT = temp at 1.8 µA/˚K 2. Remove short, adjust R2 for correct reading in ˚F DS005518-31 Adjustment Procedure 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 (µV/˚C) R1 ( Ω) R2 (Ω) Voltage Across R1 @ 25˚C Voltage Across R2 (mV) (mV) J T K S 52.3 42.8 40.8 6.4 523 1.24k 432 1k 15.60 12.77 12.17 1.908 14.32 11.78 11.17 1.766 412 953Ω 63.4 150Ω Typical supply current 50 µA www.national.com 6 LM185-1.2/LM285-1.2/LM385-1.2 Typical Applications (Continued) Centigrade Thermometer DS005518-1 Calibration 1. Adjust R1 so that V1 = temp at 1 mV/˚K 2. Adjust V2 to 273.2 mV †IQ for 1.3V to 1.6V battery voltage = 50 µA to 150 µA Schematic Diagram DS005518-7 7 www.national.com LM185-1.2/LM285-1.2/LM385-1.2 Physical Dimensions inches (millimeters) unless otherwise noted TO-46 Metal Can Package (H) Order Number LM185H-1.2, LM185H-1.2/883, LM185BXH-1.2, LM185BYH-1.2, LM285H-1.2, or LM285BXH-1.2 NS Package Number H02A SOT-23 Package (M3) Order Number LM385M3-1.2 NS Package Number MA03B www.national.com 8 LM185-1.2/LM285-1.2/LM385-1.2 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Small Outline (SO-8) Package Order Number LM285M-1.2, LM285BXM-1.2, LM285BYM-1.2 LM385M-1.2, LM385BM-1.2, LM385BXM-1.2, LM385BYM-1.2 NS Package Number M08A TO-92 Plastic Package (Z) Order Number LM285Z-1.2, LM285BXZ-1.2 LM285BYZ-1.2, LM385Z-1.2, LM385BZ-1.2 LM385BXZ-1.2 or LM385BYZ-1.2 NS Package Number Z03A 9 www.national.com LM185-1.2/LM285-1.2/LM385-1.2 Micropower Voltage Reference Diode Notes LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 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