LM385-2.5

LM185-2.5/ LM285-2.5/LM385-2.5 Micropower Voltage Reference FEATURES s s s s DESCRIPTIO 20µA to 20mA Operating Range Guaranteed 1% Initial Voltage Tolerance Guaranteed 1Ω Dynamic Impedance Very Low Power Consumption APPLICATIO S s s s s s Portable Meter References Portable Test Instruments Battery-Operated Systems Panel Meters Current Loop Instrumentation The LM185-2.5 is a two-terminal band gap reference diode that has been designed for applications which require precision performance with micropower operation. The device provides guaranteed operation specifications at currents as low as 20µA. The nominal voltage is 2.5V with both 1% and 2% tolerances available. Some additional features are: maximum dynamic impedance of 1Ω, low noise and excellent stability over time and temperature. The advanced design, processing and testing techniques make Linear’s LM185-2.5 a superior choice over previous designs. A circuit for cold junction compensation of a thermocouple is shown below. For applications requiring guaranteed temperature drift, see the LT1034 data sheet. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO Thermocouple Cold Junction Compensator IQ ≈ 50µA 16k 1M 2 MERCURY CELLS 2.6V LM385-2.5 950Ω 450Ω 10k ADJUST FOR 12.17mV AT 25°C ACROSS 450Ω LM185-2.5 TA01 OUTPUT VOLTAGE CHANGE (mV) VIN LM334 100k W.W. ZERO V– RSET 2k TYPE K + – METER U Reverse Voltage Change 16 –55°C ≤ TA ≤ +125°C 12 8 4 0 –4 0.01 0.1 1 10 REVERSE CURRENT (mA) 100 LM185-2.5 TA02 U U 1 LM185-2.5/ LM285-2.5/LM385-2.5 ABSOLUTE AXI U RATI GS U WW W (Note 1) Reverse Breakdown Current ................................ 30mA Forward Current .................................................. 10mA Operating Temperature Range LM185-2.5 (OBSOLETE) ............ – 55°C to 125°C LM285-2.5 ...................................... – 40°C to 85°C LM385-2.5 ........................................... 0°C to 70°C Storage Temperature Range LM185-2.5 (OBSOLETE) ............ – 65°C to 150°C LM285-2.5 .................................... – 65°C to 150°C LM385-2.5 .................................... – 65°C to 150°C Lead Temperature (Soldering, 10 sec.)................ 300°C PACKAGE/ORDER I FOR ATIO BOTTOM VIEW ORDER PART NUMBER LM185H-2.5 LM285H-2.5 LM385H-2.5 LM385BH-2.5 (NOTE 3) H PACKAGE 2-LEAD TO-46 METAL CAN TJMAX = 150°C, θJA = 440°C/W, θJC = 80°C/W OBSOLETE PACKAGE Consider the S8 or Z Packages for Alternate Source TOP VIEW NC NC NC 1 2 3 4 8 7 6 5 NC (DO NOT USE) NC S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 220°C/W Consult LTC Marketing for parts specified with wider operating temperature ranges. 2 U BOTTOM VIEW W U ORDER PART NUMBER LM285Z-2.5 LM385Z-2.5 LM385BZ-2.5 (NOTE 3) Z PACKAGE 3-LEAD TO-92 PLASTIC TJMAX = 100°C, θJA = 160°C/W ORDER PART NUMBER LM285S8-2.5 LM385S8-2.5 LM385BS8-2.5 S8 PART MARKING 2852 3852 3852B LM185-2.5/ LM285-2.5/LM385-2.5 The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 2) SYMBOL VZ PARAMETER Reverse Breakdown Voltage CONDITIONS TA = 25°C, 20µA ≤ IR ≤ 20mA LM185-2.5/285-2.5 LM385-2.5 LM385B-2.5 (Note 3) 20µA ≤ IR ≤ 20mA (Note 3) TMIN ≤ TA ≤ TMAX 20µA ≤ IR ≤ 1mA TA = 25°C TMIN ≤ TA ≤ TMAX 1mA ≤ IR ≤ 20mA TA = 25°C TMIN ≤ TA ≤ TMAX rZ Reverse Dynamic Impedance IR = 100µA (Note 4) TA = 25°C TMIN ≤ TA ≤ TMAX 10Hz ≤ f ≤ 10kHz, IR = 100µA TA = 25°C ± 0.1°C, IR = 100µA q ELECTRICAL CHARACTERISTICS LM185-2.5/285-2.5 MIN TYP MAX 2.462 2.500 2.538 LM385-2.5/385B-2.5 MIN TYP MAX UNITS V V V ppm/°C 2.425 2.462 20 8 20 1.0 1.5 10 20 0.2 q 2.500 2.575 2.500 2.538 20 8 20 2.0 2.5 20 25 0.4 120 20 1.0 1.5 ∆VZ ∆Temp IMIN ∆VZ ∆IR Average Temperature Coefficient Minimum Operating Current Reverse Breakdown Voltage Change With Current µA mV mV mV mV Ω Ω µV ppm/kHr q q 0.6 1.5 en ∆VZ ∆Time Wide Band Noise (RMS) Long Term Stability 120 20 Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: All specifications are for TA = 25°C unless otherwise noted. For the LM185-2.5 TMIN = – 55°C and TMAX = 125°C. For LM285-2.5, TMIN = – 40°C and TMAX = 85°C. For LM385-2.5, TMIN = 0°C and TMAX = 70°C. Note 3: For very low initial tolerance, consult LT1004 data sheet. The LT1004 is a low cost, pin for pin substitution device. For guaranteed temperature coefficient consult the LT1034-2.5 data sheet. Note 4: Guaranteed but not tested. 3 LM185-2.5/ LM285-2.5/LM385-2.5 TYPICAL PERFOR A CE CHARACTERISTICS Reverse Characteristics 100 –55°C TO 125°C REVERSE CURRENT (µA) 10 FORWARD VOLTAGE (V) 1.2 REFERENCE VOLTAGE (V) 1 0.1 0 0.5 1.0 1.5 2.0 REVERSE VOLTAGE (V) 2.5 3.0 Reverse Dynamic Impedance 1000 f = 25Hz –55°C TO 125°C DYNAMIC IMPEDANCE (Ω) 100 DYNAMIC IMPEDANCE (Ω) 100 NOISE (nV/√Hz) 10 1 0.1 0.01 1 10 0.1 REVERSE CURRENT (mA) Filtered Output Noise 120 100mA INTEGRATED NOISE (µVRMS) 100 80 60 40 R VOLTAGE (V) 20 0 100 4 UW LM185-2.5 • TPC01 LM185-2.5 • TPC05 Forward Characteristics 1.6 TA = 25°C 2.525 2.520 2.515 2.510 2.505 2.500 2.495 2.490 2.485 Temperature Drift 0.8 0.4 0 0.01 1 10 0.1 FORWARD CURRENT (mA) 100 2.480 –55 –35 –15 5 25 45 65 85 105 125 TEMPERATURE (°C) LM185-2.5 • TPC03 LM185-2.5 • TPC02 Reverse Dynamic Impedance 10k TA = 25°C IR = 100µA 1k Noise Voltage 1400 1200 1000 800 600 400 10 1 200 100 0.1 10 100 10k 1k FREQUENCY (Hz) 100k 1M 0 10 100 1k 10k FREQUENCY (Hz) 100k LM185-2.5 • TPC05 LM185-2.5M • TPC06 Response Time 4.0 C 3.0 2.0 1.0 0 5V INPUT 1k 10k 100k LM185-2.5 • TPC07 OUTPUT 24k VIN VOUT RC LOW PASS 0 0 100 TIME (µS) LM185-2.5 • TPC08 500 CUTOFF FREQUENCY (Hz) LM185-2.5/ LM285-2.5/LM385-2.5 SCHE ATIC DIAGRA W + 7.5k Q4 Q3 20pF Q1 Q7 20pF Q11 600k Q10 Q2 Q5 Q9 100k 500Ω Q6 60k Q8 Q14 500k 50k 500k Q12 Q13 200k 300k PACKAGE DESCRIPTIO 0.209 – 0.219 (5.309 – 5.537) 0.178 – 0.195 (4.521 – 4.953) 0.500 (12.700) MIN * REFERENCE PLANE 0.016 – 0.021** (0.406 – 0.533) DIA U W – LM185-2.5 SD01 H Package 2-Lead and 3-Lead TO-46 Metal Can (Reference LTC DWG # 05-08-1340) 0.085 – 0.105 (2.159 – 2.667) 0.050 (1.270) TYP 0.100 (2.540) TYP PIN 1 0.050 (1.270) TYP FOR 3-LEAD PACKAGE ONLY 0.025 (0.635) MAX 45° 0.036 – 0.046 (0.914 – 1.168) 0.028 – 0.048 (0.711 – 1.219) H02/03(TO-46) 1098 *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND 0.045" BELOW THE REFERENCE PLANE 0.016 – 0.024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) OBSOLETE PACKAGE 5 LM185-2.5/ LM285-2.5/LM385-2.5 PACKAGE DESCRIPTIO U S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 8 7 6 5 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157** (3.810 – 3.988) SO8 1298 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0°– 8° TYP 2 3 4 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0.014 – 0.019 (0.355 – 0.483) TYP *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 0.016 – 0.050 (0.406 – 1.270) 0.050 (1.270) BSC 6 LM185-2.5/ LM285-2.5/LM385-2.5 PACKAGE DESCRIPTIO U Z Package 3-Lead Plastic TO-92 (Similar to TO-226) (Reference LTC DWG # 05-08-1410) 0.180 ± 0.005 (4.572 ± 0.127) 0.90 (2.286) NOM 0.050 UNCONTROLLED (1.270) LEAD DIMENSION MAX 5° NOM 0.016 ± 0.003 (0.406 ± 0.076) 0.060 ± 0.010 (1.524 ± 0.254) 0.015 ± 0.002 (0.381 ± 0.051) 0.098 +016/–0.04 (2.5 +0.4/–0.1) 2 PLCS Z3 (TO-92) 0401 0.060 ± 0.005 (1.524± 0.127) DIA 0.180 ± 0.005 (4.572 ± 0.127) 0.500 (12.70) MIN 0.050 (1.27) BSC 0.140 ± 0.010 (3.556 ± 0.127) TO-92 TAPE AND REEL REFER TO TAPE AND REEL SECTION OF LTC DATA BOOK FOR ADDITIONAL INFORMATION 10° NOM Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of circuits as described herein will not infringe on existing patent rights. 7 LM185-2.5/ LM285-2.5/LM385-2.5 TYPICAL APPLICATI 9V REFERENCE FROM A 9V BATTERY RELATED PARTS PART NUMBER LT1634 DESCRIPTION Micropower Shunt Voltage Reference COMMENTS 0.05% Initial Accuracy, 10ppm/°C Maximum Tempco Output Voltage: 1.25V, 2.5V, 4.096V and 5V 8 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 q FAX: (408) 434-0507 UO 220k S V+ 3.7V ≤ V + ≤ 30V LM334 R 2.7k 2.5V LM385-2.5 2.5V LM385-2.5 OPERATION OVER A WIDE SUPPLY RANGE LM185-2.5 TA03 185fc LT/CP 0801 1.5K REV C • PRINTED IN USA q www.linear.com © LINEAR TECHNOLOGY CORPORATION 1992