LM185/LM285/LM385 Adjustable Micropower Voltage References General Description The LM185/LM285/LM385 are micropower 3-terminal adjustable band-gap voltage reference diodes. Operating from 1.24 to 5.3V and over a 10µA to 20mA 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 band-gap reference uses only transistors and resistors, low noise and good long-term stability result. Careful design of the LM185 has made the device 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 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 is rated for operation over a −55˚C to 125˚C temperature range, while the LM285 is rated −40˚C to 85˚C and the LM385 0˚C to 70˚C. The LM185 is available in a hermetic TO-46 package and a leadless chip carrier package, while the LM285/LM385 are available in a low-cost TO-92 molded package, as well as S.O. Features n n n n n Adjustable from 1.24V to 5.30V Operating current of 10µA to 20mA 1% and 2% initial tolerance 1Ω dynamic impedance Low temperature coefficient Connection Diagrams TO-92 Plastic Package TO-46 Metal Can Package 00525009 00525001 Bottom View Bottom View SOIC Package 20-Leadless Chip Carrier 00525010 Top View 00525015 Top View © 2005 National Semiconductor Corporation DS005250 www.national.com LM185/LM285/LM385 Adjustable Micropower Voltage Reference February 2005 LM185/LM285/LM385 Ordering Information Package Temperature Range −55˚C to 125˚C −40˚C to 85˚C 0˚C to 70˚C NSC Drawing LM185BH LM185BH/883 TO-46 H03H LM185BYH LM185BYH/883 TO-92 LM285BXZ LM385BXZ LM285BYZ LM385BYZ LM285Z LM385BZ LM285M LM385M LM285BYM LM385BM Z03A LM385Z 8-Pin SOIC 20-Leadless Chip Carrier LM185BE/883 E20A Block Diagram 00525013 Typical Applications 1.2V Reference 5.0V Reference 00525014 00525002 www.national.com M08A 2 Storage Temperature If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Soldering Information (Note 2) −55˚C to 150˚C TO-92 Package (10 sec.) 260˚C TO-46 Package (10 sec.) 300˚C SO Package Reverse Current 30mA Vapor Phase (60 sec.) 215˚C Forward Current 10mA Infrared (15 sec.) 220˚C Operating Temperature Range (Note 3) LM185 Series −55˚C to 125˚C LM285 Series −40˚C to 85˚C LM385 Series 0˚C to 70˚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, LM285 LM385 LM185BX, LM185BY Parameter Conditions LM385BX, LM185B, LM285BX, Typ LM285 LM285BY IR = 100µA Tested Design Tested Design Limit Limit Limit Limit Limit Limit Limit Limit (Note 5) (Note 6) (Note 5) (Note 6) (Note 5) (Note 6) (Note 5) (Note 6) 1.265 1.270 1.240 1.252 1.255 1.265 1.270 1.215 1.205 1.215 1.215 1.205 1.240 1.252 1.255 1.228 1.215 IMIN < IR < 1mA Change with Current 1mA < IR < 20mA V (max) 1.228 Reference Voltage Units (Limit) Typ Tested Design Tested Design Reference Voltage LM385 LM385BY V (min) 0.2 1 1.5 1 1.5 0.2 1 1.5 1 1.5 mV 4 10 20 10 20 5 15 25 15 25 (max) Dynamic Output IR = 100µA, f = 100Hz Impedance Reference Voltage IAC = 0.1 IR VOUT = VREF 0.3 0.4 VOUT = 5.3V 0.7 1 Ω IR = 100µA Change with Output mV 1 3 6 3 6 2 5 10 5 10 13 20 25 20 25 16 30 35 30 35 nA (max) (max) Voltage Feedback Current Minimum Operating VOUT = VREF 6 9 10 9 10 7 11 13 11 13 µA Current (see curve) VOUT = 5.3V 30 45 50 45 50 35 55 60 55 60 (max) Output Wideband IR = 100µA, 10Hz < f < 10kHz Noise VOUT = VREF 50 50 VOUT = 5.3V 170 170 3 µVrms www.national.com LM185/LM285/LM385 Absolute Maximum Ratings (Note 1) LM185/LM285/LM385 Electrical Characteristics (Note 4) (Continued) LM185, LM285 LM385 LM185BX, LM185BY Parameter Conditions LM385BX, LM185B, LM285BX, LM285 LM385BY LM285BY Typ Units (Limit) Typ Tested Design Tested Design Tested Design Tested Design Limit Limit Limit Limit Limit Limit Limit Limit (Note 5) (Note 6) (Note 5) (Note 6) (Note 5) (Note 6) (Note 5) (Note 6) X Suffix 30 30 ppm/˚c Coefficient (Note 7) Y Suffix 50 50 (max) Long Term Stability IR = 100µA, T = 1000 Hr, Average Temperature IR = 100µA LM385 All Others 150 150 20 150 20 150 ppm TA = 25˚C ± 0.1˚C 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 for military specifications. Note 3: For elevated temperature operation, TJmax is: LM185 150˚C LM285 125˚C LM385 100˚C Thermal Resistance θJA (Junction to Ambient) TO-92 180˚C/W (0.4" leads) TO-46 SO-8 440˚C/W 165˚C/W 170˚C/W (0.125" leads) θJC (Junction to Case) N/A 80˚C/W N/A Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at TA = TJ = 25˚C. Unless otherwise specified, all parameters apply for VREF < VOUT < 5.3V. Note 5: Guaranteed and 100% production tested. Note 6: Guaranteed, but not 100% production tested. These limits are not to be 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 from TMIN to TMAX, divided by TMAX − TMIN. The measured temperatures are −55, −40, 0, 25, 70, 85, 125˚C. www.national.com 4 LM185/LM285/LM385 Typical Performance Characteristics Temperature Drift of 3 Representative Units Feedback Current 00525017 00525016 Minimum Operating Current Reverse Characteristics 00525018 00525019 Reverse Characteristics Forward Characteristics 00525020 00525021 5 www.national.com LM185/LM285/LM385 Typical Performance Characteristics (Continued) Output Noise Voltage Dynamic Output Impedance 00525023 00525022 Response Time 00525024 Temperature Coefficient Typical LM185 LM285 LM385 00525004 www.national.com 6 LM185/LM285/LM385 Typical Applications Precision 10V Reference Low AC Noise Reference 00525025 00525026 25V Low Current Shunt Regulator 200 mA Shunt Regulator 00525027 00525028 7 www.national.com LM185/LM285/LM385 Typical Applications (Continued) Series-Shunt 20 mA Regulator High Efficiency Low Power Regulator 00525029 00525030 Voltage Level Detector Voltage Level Detector 00525031 00525032 Fast Positive Clamp 2.4V + ∆VD1 Bidirectional Clamp ± 2.4V 00525034 00525033 www.national.com 8 LM185/LM285/LM385 Typical Applications (Continued) Bidirectional Adjustable Clamp ± 1.8V to ± 2.4V Bidirectional Adjustable Clamp ± 2.4V to ± 6V 00525036 00525035 Simple Floating Current Detector Current Source 00525038 00525037 9 www.national.com LM185/LM285/LM385 Typical Applications (Continued) Precision Floating Current Detector 00525039 *D1 can be any LED, VF=1.5V to 2.2V at 3 mA. D1 may act as an indicator. D1 will be on if ITHRESHOLD falls below the threshold current, except with I=O. Centigrade Thermometer, 10mV/˚C Freezer Alarm 00525012 00525011 www.national.com 10 LM185/LM285/LM385 Schematic Diagram 00525008 11 www.national.com LM185/LM285/LM385 Physical Dimensions inches (millimeters) unless otherwise noted 20-Leadless Chip Carrier (E) NS Package Number E20A TO-46 Metal Can Package (H) NS Package Number H03H www.national.com 12 LM185/LM285/LM385 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) SO Package (M) NS Package Number M08A TO-92 Plastic Package (Z) NS Package Number Z03A 13 www.national.com LM185/LM285/LM385 Adjustable Micropower Voltage Reference Notes 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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