LM385/LM385B Adjustable Micropower Voltage Reference n FEATURES n DESCRIPTION The LM385 is micropower 3-terminal adjustable l Adjustable from 1.24V to 5.3V. l Operating Current from 10µA to 20mA. l Low Temperature Coefficient. l 1% and 2% Initial Tolerance. l Low Dynamic Impedance. band-gap voltage reference. Operating from 1.24V to 5.3V and over 10µA to 20mA current range. They feature exceptionally low dynamic impedance and good temperature stability. Onchip trimming is used to achieve tight voltage tolerance. Since the LM385 band-gap reference n APPLICATIONS uses only transistors and resistors, low noise l Portable, Battery-Powered Equipment. and good longterm stability result. l Instrumentation. Careful design of the LM385 has made the de- l Process Control. vice tolerant of capacitive loading, making it l Energy Management. easy to use in almost any reference application. l Product Testing. The wide dynamic operating range allows its l Automotive. use with widely varying supplies with excellent l Precision Audio Components. regulation. n TYPICAL APPLICATION CIRCUIT The extremely low power drain of the LM385 makes it useful for micropower circuitry. This V IN voltage reference can be used to make portable RS meters, regulators or general purpose analog 1.24V + IR - FB circuitry with battery life approaching shelf life. Further, the wide operating current allows it to replace older references with a tighter tolerance LM385 part. Precision 1.24V Voltage Reference Analog Integrations Corporation 4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw DS-385B-01 012102 1 LM385/LM385B n ORDERING INFORMATION LM385X-CXXX PIN CONFIGURATION PACKING TYPE BG: BAG TR: TAPE & REEL TB: TUBE (for SO-8) SOT-89 TOP VIEW 1: FB 2: 3: + PACKAGE TYPE X: SOT-89 Z: TO-92 S: SMALL OUTLINE 1 2 3 TO-92 1 TOP VIEW 1: FB 2: + 3: - TOLERANCE Default: 2% B: 1% Example: LM385-CXTR à 2% version, in SOT-89 Package & Taping & Reel Packing Type (CS is not available in BAG packing type.) 2 3 SO-8 TOP VIEW NC 1 8 + NC 2 7 NC NC 3 6 NC - 4 5 FB n ABSOLUTE MAXIMUM RATINGS Reverse Current ....… ................................… … … … … ............................................ 30mA Forward Current … … … ....................................… ..… … … … .....................................10mA Operating Temperature Range. .… … … … … … … … .… … … ................… ........ 0°C to 70°C Storage Temperature ...................................… … .… … … … ....................... -65°C to 150°C Lead Temperature TO-92 Package Soldering (10 seconds) ..................… … … … … … ..… … ................ 260°C SO Package Vapor phase (60 seconds) ............… … … … … … … … ........................ 215°C n TEST CIRCUIT Refer to TYPICAL APPLICATION CIRCUIT. 2 LM385/LM385B n ELECTRICAL CHARACTERISTICS (T =25°C, unless otherwise specified.) A PARAMETER SYMBOL MIN. TEST CONDITIONS Reverse Voltage LM385B IR=100µA Reverse Voltage Change with Current VR LM385 IRMIN ≤IR ≤1mA ∆VR 1mA≤IR ≤20mA VOUT =1.24V Minimum Operating Current 1.228 1.215 VOUT =5.3V TYP. MAX. UNIT 1.240 1.240 1.252 1.265 V 0.2 1 5 15 7 11 IRMIN 35 55 ZR 0.4 mV µA IR=100µA, f=100Hz Dynamic Output Impedance IAC=0.1IR, VOUT =1.24V, 1 VOUT =5.3V Reference Voltage Change with Output Voltage Ω IR=100µA Feedback Current IFB 2 5 mV 8 20 nA IR=100µA, 10Hz<f<10KHz Output Wideband Noise eN VOUT =1.24V, VOUT =5.3V Average Temperature IR=100µA Coefficient (Note) IR=100µA, T=1000Hrs, Long Term Stability Note : µVRMS 50 170 TA=25°C±0.1°C αVR 100 ppm/°C ∆VR/∆t 20 ppm The average temperature coefficient is defined as the maximum deviation of reverse voltage at all measured temperatures from TMIN to TMAX, divided by TMAX - TMIN. The measured temperatures are 0°C, 25°C, 50°C and 70°C. n TYPICAL PERFORMANCE CHARACTERISTICS 100 TA= 25° C TA= -55° C 0.8 Reverse Current ( µA) Forward Voltage (V) 1.0 TA= 125 °C 0.6 0.4 0.2 0 10 TA= -55 °C TA= 25° C TA= 125° C 1 0.1 0.01 0.1 1 10 Forward Current (mA) Fig. 1 Forward characteristics 100 0 0.2 0.4 0.6 0.8 1 1.2 1.4 Reverse Voltage (V) Fig. 2 Reverse Characteristics 3 LM385/LM385B n TYPICAL PERFORMANCE CHARACTERISTICS (Continued) 5 1.27 Output Voltage Change (mV) Reference voltage (V) IR =100µA 1.25 1.23 4 3 2 TA= 25° C TA= 80° C 1.21 -50 0 50 100 TA= -55° C 1 0 125 0.01 0.1 Temperature (°C) Fig. 3 Temperature Drift of 3 Representative Units 1 10 100 Reverse Current (mA) Fig. 4 Reverse Characteristics 10 80 Feedback Current (nA) Minimum Current (µA) I R=100µA 60 40 20 0 8 1 2 3 4 5 6 VOUT=VREF VOUT=5.3V 4 2 0 6 -20 0 20 40 60 80 100 120 Temperature ( °C) Fig. 6 Feedback Current Output Voltage (V) Fig. 5 Minimum Operating Current 10K 5 I R=100µA V OUT=5.3V Input Output 3 1K 50K V OUT 2 + 1 V OUT= V REF Noise Voltage (V) 4 120K - 100 364K 0 10 Input 10 0 -50 0 50 100 150 Time (µS) Fig. 7 Response Time 200 250 10 100 1K 10K 100K Frequency (Hz) Fig. 8 Output Noise Voltage ( nV / Hz ) 4 LM385/LM385B n n BLOCK DIAGRAM SYMBOL + + 1.2 + - FB FB 7µ A - - n PIN DESCRIPTIONS PIN + - sinks current with a range from 20µA to 20mA for normal applications. And a stable positive voltage, relative to Pin-, occurs on Pin+. PIN - - Pin- sources current for normal application. The current value is the same as Pin+. PIN NC - Not connected. n APPLICATION EXAMPLES V IN R4 VIN 50µA<I<200mA FB + R1 120K R3 VOUT 2.5V LM385 2N2219 R3 1K + LM385 R2 120K Fig. 9 200mA Shunt Regulator 100 µA<I<5mA FB R1 120K VOUT 25V R2 2.4M 2N5115 Fig. 10 25V Low Current Shunt Regulator V IN + R1 120K R1 FB + FB - - 2N2905 D1 2N3964 R2 120K R3 200 1 µA<IOUT <100mA I OUT=1.24V/R1 Fig. 11 Current Source R2 1M <-12V LED ON -5V Fig. 12 Voltage Level Detector 5 LM385/LM385B n APPLICATION EXAMPLES D1 (Continued) R1 120K + FB R2 1M R3 330 >-12V LED ON -5V Fig. 13 Voltage Level Detector n PHYSICAL DIMENSIONS l SOT-89 (unit: mm) D A SYMBOL MIN MAX C A 1.40 1.60 B 0.36 0.48 C 0.35 0.44 D 4.40 4.60 D1 1.62 1.83 E 2.29 2.60 D1 H E L B e e1 l e 1.50 (TYP.) e1 3.00 (TYP.) H 3.94 4.25 L 0.89 1.20 SOT-89 Marking Part No. Marking LM385CX AI01 LM385BCX AIB01 6 LM385/LM385B l TO-92 (unit: mm) E L A SYMBOL MIN MAX A 4.32 5.33 C C e1 D 0.38 (TYP.) D 4.40 5.20 E 3.17 4.20 e1 1.27 (TYP.) L 12.7 - l 8 LEAD PLASTIC SO (unit: mm) D H E e SYMBOL MIN MAX A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 4.80 5.00 E 3.80 4.00 e A A1 C B 1.27(TYP) H 5.80 6.20 L 0.40 1.27 L 7