LM185-2.5/ LM285-2.5/LM385-2.5 Micropower Voltage Reference U FEATURES ■ ■ ■ ■ DESCRIPTIO 20µA to 20mA Operating Range Guaranteed 1% Initial Voltage Tolerance Guaranteed 1Ω Dynamic Impedance Very Low Power Consumption 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. U APPLICATIO S ■ ■ ■ ■ ■ Portable Meter References Portable Test Instruments Battery-Operated Systems Panel Meters Current Loop Instrumentation For applications requiring guaranteed temperature drift, see the LT1034 data sheet. , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO Thermocouple Cold Junction Compensator Reverse Voltage Change 16 VIN 16k 1M 2 MERCURY CELLS 2.6V LM334 100k W.W. ZERO V– RSET 2k LM385-2.5 950Ω TYPE K 450Ω + – METER 10k ADJUST FOR 12.17mV AT 25°C ACROSS 450Ω LM185-2.5 TA01 OUTPUT VOLTAGE CHANGE (mV) IQ ≈ 50µA –55°C ≤ TA ≤ +125°C 12 8 4 0 –4 0.01 0.1 1 10 REVERSE CURRENT (mA) 100 LM185-2.5 TA02 1 LM185-2.5/ LM285-2.5/LM385-2.5 W W W AXI U U ABSOLUTE RATI GS (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 U W U PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER BOTTOM VIEW BOTTOM VIEW LM185H-2.5 LM285H-2.5 LM385H-2.5 LM385BH-2.5 H PACKAGE 2-LEAD TO-46 METAL CAN Z PACKAGE 3-LEAD TO-92 PLASTIC LM285Z-2.5 LM385Z-2.5 LM385BZ-2.5 (NOTE 3) TJMAX = 100°C, θJA = 160°C/W (NOTE 3) TJMAX = 150°C, θJA = 440°C/W, θJC = 80°C/W ORDER PART NUMBER OBSOLETE PACKAGE Consider the S8 or Z Packages for Alternate Source ORDER PART NUMBER TOP VIEW NC 1 8 NC 2 7 NC 3 6 4 5 S8 PACKAGE 8-LEAD PLASTIC SO NC NC (DO NOT USE) TJMAX = 150°C, θJA = 220°C/W Consult LTC Marketing for parts specified with wider operating temperature ranges. 2 LM285S8-2.5 LM385S8-2.5 LM385BS8-2.5 S8 PART MARKING 2852 3852 3852B LM185-2.5/ LM285-2.5/LM385-2.5 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 2) SYMBOL PARAMETER CONDITIONS VZ Reverse Breakdown Voltage TA = 25°C, 20µA ≤ IR ≤ 20mA LM185-2.5/285-2.5 LM385-2.5 LM385B-2.5 (Note 3) LM185-2.5/285-2.5 MIN TYP MAX 2.462 Average Temperature Coefficient IMIN Minimum Operating Current TMIN ≤ TA ≤ TMAX ● ∆VZ ∆IR Reverse Breakdown Voltage Change With Current 20µA ≤ IR ≤ 1mA TA = 25°C TMIN ≤ TA ≤ TMAX ● 1mA ≤ IR ≤ 20mA TA = 25°C TMIN ≤ TA ≤ TMAX ● IR = 100µA (Note 4) TA = 25°C TMIN ≤ TA ≤ TMAX ● Reverse Dynamic Impedance 20µA ≤ IR ≤ 20mA (Note 3) 20 8 0.2 UNITS 2.538 2.425 2.462 ∆VZ ∆Temp rZ 2.500 LM385-2.5/385B-2.5 MIN TYP MAX V V V 2.500 2.575 2.500 2.538 20 ppm/°C 20 µA 1.0 1.5 2.0 2.5 mV mV 10 20 20 25 mV mV 1.0 1.5 Ω Ω 20 0.6 1.5 8 0.4 en Wide Band Noise (RMS) 10Hz ≤ f ≤ 10kHz, IR = 100µA 120 120 µV ∆VZ ∆Time Long Term Stability TA = 25°C ± 0.1°C, IR = 100µA 20 20 ppm/kHr 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 U W TYPICAL PERFOR A CE CHARACTERISTICS Reverse Characteristics Forward Characteristics TA = 25°C 10 1 2.520 REFERENCE VOLTAGE (V) FORWARD VOLTAGE (V) –55°C TO 125°C REVERSE CURRENT (µA) Temperature Drift 2.525 1.6 100 1.2 0.8 0.4 2.515 2.510 2.505 2.500 2.495 2.490 2.485 0.1 0.5 0 1.0 1.5 2.0 REVERSE VOLTAGE (V) 2.5 0 0.01 3.0 1 10 0.1 FORWARD CURRENT (mA) LM185-2.5 • TPC01 Reverse Dynamic Impedance LM185-2.5 • TPC03 Reverse Dynamic Impedance Noise Voltage 10k 1400 f = 25Hz –55°C TO 125°C 10 1 1200 1k 1000 NOISE (nV/√Hz) DYNAMIC IMPEDANCE (Ω) TA = 25°C IR = 100µA 100 5 25 45 65 85 105 125 TEMPERATURE (°C) LM185-2.5 • TPC02 1000 DYNAMIC IMPEDANCE (Ω) 2.480 –55 –35 –15 100 100 10 800 600 400 1 200 0.1 0.01 1 10 0.1 REVERSE CURRENT (mA) 0.1 100 100 10 10k 1k FREQUENCY (Hz) LM185-2.5 • TPC05 100k 0 1M 10 100 1k 10k FREQUENCY (Hz) LM185-2.5M • TPC06 LM185-2.5 • TPC05 Filtered Output Noise Response Time 120 R 4.0 C 80 3.0 VOLTAGE (V) INTEGRATED NOISE (µVRMS) 100mA 100 60 40 RC LOW PASS 20 OUTPUT 2.0 24k 1.0 VIN VOUT 0 5V INPUT 0 100 1k 10k 100k CUTOFF FREQUENCY (Hz) LM185-2.5 • TPC07 4 0 0 100k 100 500 TIME (µS) LM185-2.5 • TPC08 LM185-2.5/ LM285-2.5/LM385-2.5 W W SCHE ATIC DIAGRA + 7.5k Q13 200k Q12 Q4 Q3 Q7 20pF Q11 20pF Q1 50k 600k 500k Q10 Q5 Q2 300k Q9 Q6 100k Q8 500Ω Q14 60k 500k – LM185-2.5 SD01 U PACKAGE DESCRIPTIO H Package 2-Lead and 3-Lead TO-46 Metal Can (Reference LTC DWG # 05-08-1340) 0.209 – 0.219 (5.309 – 5.537) 0.178 – 0.195 (4.521 – 4.953) REFERENCE PLANE 0.085 – 0.105 (2.159 – 2.667) 0.500 (12.700) MIN 0.100 (2.540) TYP 0.050 (1.270) TYP PIN 1 * 0.016 – 0.021** (0.406 – 0.533) DIA 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 U PACKAGE DESCRIPTIO 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 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) SO8 1298 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 0°– 8° TYP 0.016 – 0.050 (0.406 – 1.270) 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 6 2 3 4 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSC LM185-2.5/ LM285-2.5/LM385-2.5 U PACKAGE DESCRIPTIO 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) 0.060 ± 0.005 (1.524± 0.127) DIA 0.90 (2.286) NOM 0.180 ± 0.005 (4.572 ± 0.127) 0.500 (12.70) MIN 0.050 (1.27) BSC 0.050 UNCONTROLLED (1.270) LEAD DIMENSION MAX 0.016 ± 0.003 (0.406 ± 0.076) 0.060 ± 0.010 (1.524 ± 0.254) 0.140 ± 0.010 (3.556 ± 0.127) 5° NOM 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 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 UO TYPICAL APPLICATI S V+ 9V 3.7V ≤ V + ≤ 30V LM334 220k R 2.7k 2.5V 2.5V LM385-2.5 LM385-2.5 OPERATION OVER A WIDE SUPPLY RANGE REFERENCE FROM A 9V BATTERY LM185-2.5 TA03 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1634 Micropower Shunt Voltage Reference 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 ● FAX: (408) 434-0507 ● www.linear.com 185fc LT/CP 0801 1.5K REV C • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1992