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 2terminal band-gap voltage regulator diodes. Operating over a 20 mA to 20 mA current range, they feature exceptionally low dynamic impedance and good temperature stability. Onchip 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 b55 C to 125 C temperature range while the LM285-2.5 is rated b 40 C to 85 C and the LM385-2.5 0 C to 70 C. The LM1852.5/LM285-2.5 are available in a hermetic TO-46 package and the LM285-2.5/LM385-2.5 are also available in a lowcost TO-92 molded package, as well as S.O. The LM185-25 is also available in a hermetic leadless chip carrier package. Features Y Y Y Y Y Y g 20 mV ( g 0.8%) max. initial tolerance (A grade) Operating current of 20 mA to 20 mA 0.6X dynamic impedance (A grade) Low temperature coefficient Low voltage reference2.5V 1.2V device and adjustable device also available LM185-1.2 series and LM185 series, respectively Applications Wide Input Range Reference Micropower Reference from 9V Battery TL/H/5519 - 2 TL/H/5519-12 Connection Diagrams TO-46 Metal Can Package TO-92 Plastic Package SO Package TL/H/5519-8 Bottom View Order Number LM285Z-2.5, LM285AZ-2.5, LM285AXZ-2.5, LM285AYZ-2.5, LM285BXZ-2.5, LM285BYZ-2.5, LM385Z-2.5, LM385AZ-2.5, LM385AXZ-2.5, LM385AYZ-2.5, LM385BZ-2.5, LM385BXZ-2.5 or LM385BYZ-2.5 See NS Package Number Z03A C1995 National Semiconductor Corporation TL/H/5519 TL/H/5519 - 13 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, LM285BXH-2.5 or LM285BYH-2.5 See NS Package Number H02A TL/H/5519 - 11 Order Number LM285M-2.5, LM285AM-2.5, LM285AXM-2.5, LM285AYM-2.5, LM285BXM-2.5, LM285BYM-2.5, LM385M-2.5, LM385AM-2.5, LM385AXM-2.5, LM385AYM-2.5, LM385BM-2.5, LM385BXM-2.5 or LM385BYM-2.5 See NS Package Number M08A RRD-B30M75/Printed in U. S. A. LM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference Diode December 1994 Absolute Maximum Ratings (Note 1) Storage Temperature If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. (Note 2) Reverse Current 30 mA Forward Current 10 mA Operating Temperature Range (Note 3) b 55 C to a 125 C LM185-2.5 b 40 C to a 85 C LM285-2.5 LM385-2.5 0 C to 70 C b 55 C to a 150 C Soldering Information TO-92 Package (10 sec.) TO-46 Package (10 sec.) SO Package Vapor Phase (60 sec.) Infrared (15 sec.) 260 C 300 C 215 C 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) Parameter Conditions LM285A-2.5 LM285AX-2.5 LM285AY-2.5 Typ Tested Limit (Notes 5, 8) Reverse Breakdown Voltage IR e 100 mA 2.500 2.480 2.520 2.500 Minimum Operating Current Design Limit (Note 6) LM385A-2.5 LM385AX-2.5 LM385AY-2.5 Tested Limit (Note 5) 2.480 2.520 2.460 2.535 12 Design Limit (Note 6) 2.470 2.530 18 20 18 20 Units (Limits) V(Min) V(Max) V(Min) V(Max) mA (Max) Reverse Breakdown Voltage Change with Current IMIN s IR s 1mA 1 1.5 1 1.5 mV (Max) 1 mA s IR s 20 mA 10 20 10 20 mV (Max) Reverse Dynamic Impedance IR e 100 mA, f e 20 Hz 0.2 Wideband Noise (rms) IR e 100 mA 10 Hz s f s 10 kHz 120 mV Long Term Stability IR e 100 mA, T e 1000 Hr, TA e 25 C g 0.1 C 20 ppm Average Temperature Coefficient (Note 7) 0.6 1.5 IMIN s IR s 20 mA X Suffix Y Suffix All Others 30 50 30 50 150 2 0.6 1.5 X ppm/ C (Max) 150 Electrical Characteristics (Continued) (Note 4) Parameter Conditions LM185-2.5 LM185BX-2.5 LM185BY-2.5 LM285-2.5 LM285BX-2.5 LM285BY-2.5 Typ Tested Limit (Notes 5, 8) Reverse Breakdown Voltage TA e 25 C, 20 mA s IR s 20 mA Minimum Operating Current Design Limit (Note 6) LM385B-2.5 LM385BX-2.5 LM385BY-2.5 Tested Limit (Note 5) Design Limit (Note 6) 2.462 2.538 LM385-2.5 Tested Limit (Note 5) Units (Limit) Design Limit (Note 6) 2.5 2.462 2.538 2.425 2.575 V(Min) V(Max) 13 20 30 20 30 20 30 mA (Max) Reverse Breakdown Voltage Change with Current 20 mA s IR s 1 mA 1 1.5 2.0 2.5 2.0 2.5 mV (Max) 1 mA s IR s 20 mA 10 20 20 25 20 25 mV (Max) Reverse Dynamic Impedance IR e 100 mA, f e 20 Hz Wideband Noise (rms) Long Term Stability Average Temperature Coefficient (Note 7) 1 X IR e 100 mA, 10 Hz s f s 10 kHz 120 mV IR e 100 mA, T e 1000 Hr, TA e 25 C g 0.1 C 20 ppm IR e 100 mA X Suffix Y Suffix All Others 30 50 30 50 150 150 150 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 125 C LM385 100 C Thermal Resistance ija (Junction to Ambient) ija (Junction to Case) TO-92 TO-46 SO-8 180 C/W (0.4x Leads) 440 C/W 165 C/W 170 C/W (0.125x Leads) N/A 80 C/W N/A Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at TA e TJ e 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 b 55 C, b 40 C, 0 C, 25 C, 70 C, 85 C, 125 C. Note 8: A military RETS electrical specification available on request. 3 Typical Performance Characteristics Reverse Characteristics Reverse Characteristics Forward Characteristics Temperature Drift Reverse Dynamic Impedance Reverse Dynamic Impedance Noise Voltage Filtered Output Noise Response Time TL/H/5519 - 3 Connection Diagram TL/H/5519 - 14 Order Number LM185E-2.5/883 See NS Package Number E20A 4 LM385-2.5 Applications Micropower* 5V Regulator Micropower* 10V Reference TL/H/5519 - 10 *IQ j 30 mA standby current *IQ j 40 mA TL/H/5519 - 9 Precision 1 mA to 1 mA Current Sources *IOUT e 2.5V R2 TL/H/5519 - 4 METER THERMOMETERS 0 C-100 C Thermometer 0 F -50 F Thermometer TL/H/5519 - 5 Calibration Calibration 1. Short LM385-2.5, adjust R3 for IOUT e temp at 1mA/ K 2. Remove short, adjust R2 for correct reading in centigrade 1. Short LM385-2.5, adjust R3 for IOUT e temp at 1.8 mA/ K 2. Remove short, adjust R2 for correct reading in F 5 LM385-2.5 Applications (Continued) Micropower Thermocouple Cold Junction Compensator 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. TL/H/5519-6 Thermocouple Type J T K S Seebeck Coefficient (mV/ C) 52.3 42.8 40.8 6.4 R1 (X) R2 (X) 523 432 412 63.4 1.24k 1k 953X 150X Voltage Across R1 @ 25 C (mV) 15.60 12.77 12.17 1.908 Voltage Across R2 (mV) Improving Regulation of Adjustable Regulators 14.32 11.78 11.17 1.766 Typical supply current 50 mA TL/H/5519 - 7 Schematic Diagram TL/H/5519 - 1 6 Physical Dimensions inches (millimeters) Order Number LM185E-2.5/883 NS Package Number E20A 7 Physical Dimensions inches (millimeters) (Continued) 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, LM285BXH-2.5 or LM285BYH-2.5 NS Package Number H02A 8 Physical Dimensions inches (millimeters) (Continued) Small Outline (SO-8) Package (M) Order Number LM285M-2.5, LM285AM-2.5, LM285AXM-2.5, LM285AYM-2.5, LM285BXM-2.5, LM285BYM-2.5, LM385M-2.5, LM385AM-2.5, LM385AXM-2.5, LM385AYM-2.5, LM385BM-2.5, LM385BXM-2.5 or LM385BYM-2.5 NS Package Number M08A 9 LM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference Diode Physical Dimensions inches (millimeters) (Continued) TO-92 Plastic Package (Z) Order Number LM285Z-2.5, LM285AZ-2.5, LM285AXZ-2.5, LM285AYZ-2.5, LM285BXZ-2.5, LM285BYZ-2.5, LM385Z-2.5, LM385AZ-2.5, LM385AXZ-2.5, LM385AYZ-2.5, LM385BZ-2.5, LM385BXZ-2.5 or LM385BYZ-2.5 NS Package Number Z03A 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 OF NATIONAL SEMICONDUCTOR CORPORATION. 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