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 10A 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 -55C to 125C temperature range, while the LM285 is rated -40C to 85C and the LM385 0C to 70C. 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 Adjustable from 1.24V to 5.30V Operating current of 10A to 20mA 1% and 2% initial tolerance 1 dynamic impedance Low temperature coefficient Connection Diagrams TO-92 Plastic Package TO-46 Metal Can Package 525009 Bottom View 525001 Bottom View SOIC Package 20-Leadless Chip Carrier 525010 Top View 525015 Top View (c) 2008 National Semiconductor Corporation 5250 www.national.com LM185/LM285/LM385 Adjustable Micropower Voltage Reference January 30, 2008 LM185/LM285/LM385 Ordering Information Package Temperature Range -55C to 125C -40C to 85C NSC Drawing 0C to 70C 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 525013 Typical Applications 1.2V Reference 5.0V Reference 525014 525002 www.national.com M08A 2 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 Series LM285 Series LM385 Series Electrical Characteristics 30mA 10mA -55C to 125C -40C to 85C 0C to 70C (Note 4) LM185, LM285 Parameter Conditions Typ LM385 LM185BX, LM185BY LM185B, LM285BX, LM285BY LM385BX, LM285 IR = 100A Reference Voltage Change with Current IMIN< IR < 1mA Dynamic Output Impedance IR = 100A, 1.240 1mA < IR < 20mA IAC = 0.1 IR f= 100Hz VOUT = VREF VOUT = 5.3V Reference Voltage Change with Output Voltage 1.252 1.265 1.270 1.255 1.228 1.215 1.215 1.205 Tested Design Tested Design Limit Limit Limit Limit (Note (Note (Note (Note 5) 6) 5) 6) 1.240 1.252 1.255 1.265 1.270 V 1.228 1.215 1.215 1.205 (max) 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) 0.3 0.4 0.7 1 IR = 100A Feedback Current Units (Limit) Typ Tested Design Tested Design Limit Limit Limit Limit (Note (Note (Note (Note 5) 6) 5) 6) Reference Voltage LM385 LM385BY mV 1 3 6 3 6 2 5 10 5 10 13 20 25 20 25 16 30 35 30 35 nA (max) (max) Minimum Operating Current (see curve) VOUT = VREF 6 9 10 9 10 7 11 13 11 13 A VOUT = 5.3V 30 45 50 45 50 35 55 60 55 60 (max) Output Wideband IR = 100A, 10Hz < f < 10kHz VOUT = VREF 50 50 VOUT = 5.3V 170 170 Noise 3 Vrms www.national.com LM185/LM285/LM385 ESD Susceptibility (Note 8) 2kV Storage Temperature -55C to 150C Soldering Information TO-92 Package (10 sec.) 260C TO-46 Package (10 sec.) 300C SO Package Vapor Phase (60 sec.) 215C Infrared (15 sec.) 220C See An-450 "Surface Mounting Methods and Their Effect on Product Reliability" for other methods of soldering surface mount devices. Absolute Maximum Ratings (Note 1) LM185/LM285/LM385 LM185, LM285 Parameter Conditions LM185BX, LM185BY LM185B, LM285BX, LM285BY Typ LM385 LM385BX, LM285 LM385BY IR = 100A Long Term Stability Tested Design Tested Design Limit Limit Limit Limit (Note (Note (Note (Note 5) 6) 5) 6) X Suffix 30 30 Y Suffix 50 50 All Others IR = 100A, T = 1000 Hr, TA = 25C 0.1C 150 ppm/ c (max) 150 20 Units (Limit) Typ Tested Design Tested Design Limit Limit Limit Limit (Note (Note (Note (Note 5) 6) 5) 6) Average Temperature Coefficient (Note 7) LM385 150 20 150 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: Refer to RETS185H for military specifications. Note 3: For elevated temperature operation, TJmax is: LM185 150C LM285 125C LM385 100C Thermal Resistance JA (Junction to Ambient) TO-92 TO-46 SO-8 180C/W (0.4 leads) 440C/W 165C/W 80C/W N/A 170C/W (0.125 leads) JC (Junction to Case) N/A Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at TA = TJ = 25C. 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, 125C. Note 8: The human body model is a 100 pF capacitor discharged through a 1.5 k resistor into each pin. www.national.com 4 LM185/LM285/LM385 Typical Performance Characteristics Temperature Drift of 3 Representative Units Feedback Current 525017 525016 Minimum Operating Current Reverse Characteristics 525018 525019 Reverse Characteristics Forward Characteristics 525020 525021 5 www.national.com LM185/LM285/LM385 Output Noise Voltage Dynamic Output Impedance 525023 525022 Response Time 525024 Temperature Coefficient Typical LM185 LM285 LM385 525004 www.national.com 6 LM185/LM285/LM385 Typical Applications Precision 10V Reference Low AC Noise Reference 525025 525026 25V Low Current Shunt Regulator 200 mA Shunt Regulator 525027 525028 7 www.national.com LM185/LM285/LM385 Series-Shunt 20 mA Regulator High Efficiency Low Power Regulator 525029 525030 Voltage Level Detector Voltage Level Detector 525031 525032 Fast Positive Clamp 2.4V + VD1 Bidirectional Clamp 2.4V 525034 525033 www.national.com 8 LM185/LM285/LM385 Bidirectional Adjustable Clamp 1.8V to 2.4V Bidirectional Adjustable Clamp 2.4V to 6V 525036 525035 Simple Floating Current Detector Current Source 525038 525037 Precision Floating Current Detector 525039 9 www.national.com LM185/LM285/LM385 *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 525012 525011 Schematic Diagram 525008 www.national.com 10 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 11 www.national.com LM185/LM285/LM385 SO Package (M) NS Package Number M08A TO-92 Plastic Package (Z) NS Package Number Z03A www.national.com 12 LM185/LM285/LM385 Notes 13 www.national.com LM185/LM285/LM385 Adjustable Micropower Voltage Reference Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Design Support Amplifiers www.national.com/amplifiers WEBENCH www.national.com/webench Audio www.national.com/audio Analog University www.national.com/AU Clock Conditioners www.national.com/timing App Notes www.national.com/appnotes Data Converters www.national.com/adc Distributors www.national.com/contacts Displays www.national.com/displays Green Compliance www.national.com/quality/green Ethernet www.national.com/ethernet Packaging www.national.com/packaging Interface www.national.com/interface Quality and Reliability www.national.com/quality LVDS www.national.com/lvds Reference Designs www.national.com/refdesigns Power Management www.national.com/power Feedback www.national.com/feedback Switching Regulators www.national.com/switchers LDOs www.national.com/ldo LED Lighting www.national.com/led PowerWise www.national.com/powerwise Serial Digital Interface (SDI) www.national.com/sdi Temperature Sensors www.national.com/tempsensors Wireless (PLL/VCO) www.national.com/wireless THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION ("NATIONAL") PRODUCTS. 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