LM385BM-2.5

LM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference Diode February 2005 LM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference Diode General Description The LM185-2.5/LM285-2.5/LM385-2.5 are micropower 2-terminal band-gap voltage regulator diodes. Operating over a 20 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 LM-185-2.5 band-gap reference uses only transistors and resistors, low noise and good long term stability result. Careful design of the LM185-2.5 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 LM185-2.5 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. For applications requiring 1.2V see LM185-1.2. The LM185-2.5 is rated for operation over a −55˚C to 125˚C temperature range while the LM285-2.5 is rated −40˚C to 85˚C and the LM385-2.5 0˚C to 70˚C. The LM185-2.5/ LM285-2.5 are available in a hermetic TO-46 package and the LM285-2.5/LM385-2.5 are also available in a low-cost TO-92 molded package, as well as S.O. and SOT-23. The LM185-2.5 is also available in a hermetic leadless chip carrier package. Features n n n n n n ± 20 mV ( ± 0.8%) max. initial tolerance (A grade) Operating current of 20 µA to 20 mA 0.6Ω dynamic impedance (A grade) Low temperature coefficient Low voltage reference — 2.5V 1.2V device and adjustable device also available — LM185-1.2 series and LM185 series, respectively Connection Diagrams TO-92 Plastic Package SO Package 00551908 Bottom View Order Number LM285Z-2.5, LM285BXZ-2.5, LM285BYZ-2.5 LM385Z-2.5, LM385AXZ-2.5 LM385AYZ-2.5, LM385BZ-2.5, LM385BXZ-2.5 or LM385BYZ-2.5 See NS Package Number Z03A 00551911 Order Number LM285M-2.5, LM285BXM-2.5, LM285BYM-2.5 LM385M-2.5, LM385BM-2.5 LM385BXM-2.5 or LM385BYM-2.5 See NS Package Number M08A SOT-23 00551929 * Pin 3 is attached to the Die Attach Pad (DAP) and should be connected to Pin 2 or left floating. Order Number LM385M3-2.5 See NS Package Number MA03B © 2005 National Semiconductor Corporation DS005519 www.national.com LM185-2.5/LM285-2.5/LM385-2.5 Connection Diagrams (Continued) TO-46 Metal Can Package LCC Leadless Chip Carrier 00551913 00551914 Order Number LM185E-2.5/883 See NS Package Number E20A Bottom View Order Number LM185H-2.5, LM185H-2.5/883, LM185BXH-2.5, LM185BXH-2.5/883, LM185BYH-2.5, LM185BYH2.5/883, LM285H-2.5, or LM285BYH-2.5 See NS Package Number H02A www.national.com 2 LM185-2.5/LM285-2.5/LM385-2.5 Absolute Maximum Ratings 2) (Notes 1, LM385-2.5 Storage Temperature Soldering Information TO-92 Package (10 sec.) TO-46 Package (10 sec.) SO and SOT Package Vapor Phase (60 sec.) Infrared (15 sec.) 0˚C to 70˚C −55˚C to + 150˚C 260˚C 300˚C 215˚C 220˚C If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Reverse Current Forward Current Operating Temperature Range (Note 3) LM185-2.5 LM285-2.5 −55˚C to + 125˚C −40˚C to + 85˚C 30 mA 10 mA See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” for other methods of soldering surface mount devices. Electrical Characteristics (Note 4) LM385A-2.5 LM385AX-2.5 Parameter Conditions Typ LM385AY-2.5 Tested Limit (Note 5) Reverse Breakdown Voltage 2.500 Minimum Operating Current Reverse Breakdown Voltage Change with Current Reverse Dynamic Impedance Wideband Noise (rms) Long Term Stability 1 mA ≤ IR ≤ 20 mA IR = 100 µA, f = 20 Hz IR = 100 µA 10 Hz ≤ f ≤ 10 kHz IR = 100 µA, T = 1000 Hr, TA = 25˚C ± 0.1˚C Average Temperature Coefficient (Note 7) IMIN ≤ IR ≤ 20 mA X Suffix Y Suffix All Others 30 50 150 ppm/˚C (Max) 20 ppm 120 0.2 10 20 0.6 1.5 µV IMIN ≤ IR ≤ 1mA 1 1.5 12 18 IR = 100 µA 2.500 2.480 2.520 2.470 2.530 20 Design Limit (Note 6) V(Min) V(Max) V(Min) V(Max) µA (Max) mV (Max) mV (Max) Ω Units (Limits) 3 www.national.com LM185-2.5/LM285-2.5/LM385-2.5 Electrical Characteristics LM185-2.5 LM185BX-2.5 LM185BY-2.5 LM285-2.5 Parameter Conditions Typ LM285BX-2.5 LM285BY-2.5 Tested Limit (Note 5) (Note 8) Reverse Breakdown Voltage Minimum Operating Current Reverse Breakdown Voltage Change with Current Reverse Dynamic Impedance Wideband Noise (rms) TA = 25˚C, 20 µA ≤ IR ≤ 20 mA 13 LM385M3-2.5 20 µA ≤ IR ≤ 1 mA 1 mA ≤ IR ≤ 20 mA IR = 100 µA, f = 20 Hz IR = 100 µA, 10 Hz ≤ f ≤ 10 kHz Long Term Stability IR = 100 µA, T = 1000 Hr, TA = 25˚C ± 0.1˚C Average Temperature Coefficient (Note 7) 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-2.5 for military specifications. Note 3: For elevated temperature operation, TJ MAX is: LM185 150˚C LM285 LM385 125˚C 100˚C LM385B-2.5 LM385BX-2.5 LM385BY-2.5 LM385-2.5 Units (Limit) Design Limit (Note 6) Tested Limit (Note 5) 2.462 2.538 Design Limit (Note 6) Tested Design Limit (Note 5) 2.425 2.575 Limit (Note 6) V(Min) V(Max) 30 20 2.5 25 µA (Max) mV (Max) mV (Max) Ω 2.5 2.462 2.538 20 30 20 30 20 15 1 10 1.5 20 2.0 20 2.5 25 2.0 20 1 120 µV 20 ppm 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 SO-8 SOT-23 440˚C/W 165˚C/W 283˚C/W 80˚C/W N/A N/A www.national.com 4 LM185-2.5/LM285-2.5/LM385-2.5 Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at TA = TJ = 25˚C. Note 5: Guaranteed and 100% production tested. 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 available on request. Typical Performance Characteristics Reverse Characteristics Reverse Characteristics 00551915 00551916 Forward Characteristics Temperature Drift 00551917 00551918 Reverse Dynamic Impedance Reverse Dynamic Impedance 00551919 00551920 5 www.national.com LM185-2.5/LM285-2.5/LM385-2.5 Typical Performance Characteristics Noise Voltage (Continued) Filtered Output Noise 00551921 00551922 Response Time 00551923 Applications Wide Input Range Reference LM385-2.5 Applications Micropower 5V Reference (Note 9) 00551912 Micropower Reference from 9V Battery 00551909 Note 9: IQ . 40 µA 00551902 www.national.com 6 LM185-2.5/LM285-2.5/LM385-2.5 LM385-2.5 Applications (Continued) Micropower 10V Reference (Note 10) 00551910 Note 10: IQ . 30 µA standby current Precision 1 µA to 1 mA Current Sources 00551925 00551924 7 www.national.com LM185-2.5/LM285-2.5/LM385-2.5 LM385-2.5 Applications METER THERMOMETERS (Continued) 0˚C–100˚C Thermomemter Micropower Thermocouple Cold Junction Compensator 00551926 Calibration 1. Short LM385-2.5, adjust R3 for IOUT=temp at 1µA/˚K 2. Remove short, adjust R2 for correct reading in centigrade 0˚F–50˚F Thermomemter 00551906 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. 00551927 Calibration 1. Short LM385-2.5, adjust R3 for IOUT=temp at 1.8 µA/˚K 2. Remove short, adjust R2 for correct reading in ˚F Seebeck Thermocouple Type J T K S Typical supply current 50 µA Voltage R1 (Ω) R2 (Ω) Across R1 @ 25˚C Voltage Across R2 (mV) 14.32 11.78 11.17 1.766 Coefficient (µV/˚C) 52.3 42.8 40.8 6.4 (mV) 523 1.24k 432 1k 412 953Ω 63.4 150Ω 15.60 12.77 12.17 1.908 www.national.com 8 LM185-2.5/LM285-2.5/LM385-2.5 LM385-2.5 Applications (Continued) Improving Regulation of Adjstable Regulators 00551907 Schematic Diagram 00551901 9 www.national.com LM185-2.5/LM285-2.5/LM385-2.5 Physical Dimensions unless otherwise noted inches (millimeters) Order Number LM185E-2.5/883 NS Package Number E20A TO-46 Metal Can Package (H) Order Number LM185H-2.5, LM185H-2.5/883, LM185BXH-2.5, LM185BXH-2.5/883, LM185BYH-2.5, LM185BYH-2.5/883, LM285H-2.5, or LM285BYH-2.5 NS Package Number H02A www.national.com 10 LM185-2.5/LM285-2.5/LM385-2.5 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) SOT-23 Package (M3) Order Number LM385M3-2.5 NS Package Number MA03B 11 www.national.com LM185-2.5/LM285-2.5/LM385-2.5 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Small Outline (SO-8) Package (M) Order Number LM285M-2.5, LM285BXM-2.5, LM285BYM-2.5, LM385M-2.5, LM385BM-2.5, LM385BXM-2.5 or LM385BYM-2.5 NS Package Number M08A www.national.com 12 LM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference Diode Physical Dimensions inches (millimeters) unless otherwise noted (Continued) TO-92 Plastic Package (Z) Order Number LM285Z-2.5, LM285BXZ-2.5, LM285BYZ-2.5, LM385Z-2.5, LM385AXZ-2.5, LM385AYZ-2.5, LM385BZ-2.5, LM385BXZ-2.5 or LM385BYZ-2.5 NS Package Number Z03A National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. 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