LM385-2.5/LM385B-2.5 Micropower Voltage Reference n FEATURES n DESCRIPTION l Operating Current from 20µA to 20mA. The LM385-2.5 is a micropower 2-terminal band- l Low Temperature Coefficient. gap voltage reference, which can operate in l 1% and 2% Initial Tolerance. 20µA to 20mA current range, they feature excep- l Low Dynamic Impedance. tionally low dynamic impedance and good tem- n a perature stability. On-chip trimming is used to APPLICATIONS achieve tight voltage tolerance. Since the LM385- l Portable, Battery-Powered Equipment. l Instrumentation. l Process Control. l Energy Management. l Product Testing. Careful design of the LM385-2.5 has made the de- l Automotive. vice exceptionally tolerant of capacitive loading, l Precision Audio Components. making it easy to use in almost any reference ap- 2.5 bandgap reference uses only transistors and resistors, low noise and good long-term stability result. plication. The wide dynamic operating range allows for its use with widely varying supplies with excellent regulation. The extremely low power drain of the LM385-2.5 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. n TYPICAL APPLICATION CIRCUIT VIN RS 2.5V + - LM385-2.5 Precision 2.500V 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 w ww.analog.com.tw DS-385C-01 012102 1 LM385-2.5/LM385B-2.5 n ORDERING INFORMATION LM385X-2.5CXXX PIN CONFIGURATION SO-8 TOP VIEW PACKING TYPE BG: BAG TB: TUBE (for SO-8) TR: TAPE & REEL PACKAGE TYPE S : SMALL OUTLINE U: SOT-23 X: SOT-89 Z: TO-92 NC 1 8 + NC 2 7 NC 3 6 NC - 4 5 NC 2 SOT-23 TOP VIEW 1: 2: + 3: NC TOLERANCE Default: 2% B: 1% 1 Example: LM385-2.5CSTR à 2% version, in SO-8 Package & Taping & Reel Packing Type (CS is not available in BAG packing type.) NC 3 SOT-89 TOP VIEW 1: NC 2: 3: + 1 TO-92 TOP VIEW 1: NC 2: + 3: - 2 3 1 2 3 n ABSOLUTE MAXIMUM RATINGS Reverse Current ....… .................… … … … … … ........................................................ 30mA Forward Current … … … ....................................… .......… … … … ..............................10mA Operating Temperature Range. Storage Temperature .… … … … … … … … ............… … ......… … ........ 0°C to 70°C .............................… … … … .....… … ......................... -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 LM385-2.5/LM385B-2.5 n ELECTRICAL CHARACTERISTICS (T =25°C, unless otherwise specified.) A PARAMETER Reverse Breakdown Voltage Reverse Breakdown Voltage Change with Current TEST CONDITIONS IR=100µA LM385B-2.5 LM385-2.5 Coefficient (Note) Long Term Stability Note : TYP. MAX. UNIT VR 2.475 2.450 2.500 2.500 2.525 2.550 V ∆VR 2 mV 1mA≤IR ≤20mA ∆VR 20 mV Minimum Operating Current Average Temperature MIN. 20µA≤IR ≤1mA Reverse Dynamic Impedance IR=100µA, f=20Hz Wideband Noise (rms) SYMBOL IR=100µA, 10Hz≤ f ≤10KHz IR=100µA IR=100µA, T=1000Hrs, TA=25°C Ω ZR 1 IRMIN 13 eN 120 µVrms αVR 100 ppm/°C ∆VR /∆t 20 ppm 20 µA The average temperature coefficient is defined as the maximum deviation of reverse breakdown 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. 3 LM385-2.5/LM385B-2.5 TYPICAL PERFORMANCE CHARACTERISTICS 3 Reverse Voltage (V) Output Voltage Change (mV) 8 125 °C 2.5 -25°C 2 1.5 25°C 1 0.5 0 1 10 Reverse Current (µ A) Fig. 1 Reverse Characteristics 4 0 0.1 1 10 100 Reverse Current (mA) Fig. 2 Reverse Characteristics 2.5 1.2 2 1 25 °C -25°C 0.6 125 °C 0.4 80 °C 2 1.4 0.8 -25°C 25 °C 6 -2 0.01 100 Voltage Swing (V) Forward Voltage (V) 0.1 0.2 Input (2) 1.5 Output 100K Output (1) 1 0.5 0 12.5 Input 0 0.01 0.1 1 10 100 0 200 400 600 800 1000 Time (µS) Fig. 4 Response Time Forward Current (mA) Fig. 3 Forward Characteristics 2.52 1000 800 2.51 Noise Reference Voltage (V) n 2.5 600 400 2.49 200 2.48 -20 0 20 40 60 Temperature (°C) Fig. 5 Temperature Drift 80 100 100 1000 1000 10000 Frequency (Hz) Fig. 6 Noise Voltage (n V / Hz ) 4 LM385-2.5/LM385B-2.5 n n BLOCK DIAGRAM SYMBOL + + 2.5V + 13µA - - 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 LM385-2.5 LM385-2.5 C1 150pF C1 150pF R1 68K 2 3 IOUT - 2 . 5V R2 R1 68K 2 + 3 - -1.5V to -27V IOUT = 7 6 4 IOUT 4 R2 1.5V to 27V IOUT = + 30V 7 6 R2 -30V 2 . 5V R2 Fig. 7 Precision 1µA to 1mA Current Source 5 LM385-2.5/LM385B-2.5 n PHYSICAL DIMENSIONS 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 l H 5.80 6.20 L 0.40 1.27 SYMBOL MIN MAX A 1.00 1.30 A1 — 0.10 A2 0.70 0.90 b 0.35 0.50 C 0.10 0.25 D 2.70 3.10 E 1.40 1.80 L SOT-23 (unit: mm) C D L E H θ1 e e A A2 A1 b l 1.27(TYP) 1.90 (TYP) H 2.60 3.00 L 0.37 — θ1 1° 9° SOT-23 MARKING Part No. LM385-25CU LM385B-25CU Marking AIA2 AIB2 6 LM385-2.5/LM385B-2.5 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 SYMBOL MIN MAX A 4.32 5.33 TO-92 (unit: mm) A E L C C e1 D 0.38 (TYP.) D 4.40 5.20 E 3.17 4.20 e1 L 1.27 (TYP.) 12.7 - 7