LM285-2.5

U U FEATURES s 20µA to 20mA Operating Range s Guaranteed 1% Initial Voltage Tolerance s Guaranteed 1Ω Dynamic Impedance s Very Low Power Consumption U APPLICATIO S s Portable Meter References s Portable Test Instruments s Battery-Operated Systems s Panel Meters s Current Loop Instrumentation LM185-2.5/ LM285-2.5/LM385-2.5 Micropower Voltage Reference DESCRIPTIO 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 2 MERCURY CELLS 2.6V 16k 1M LM385-2.5 TYPE K 100k W.W. ZERO 950Ω + – METER VIN LM334 RSET V– 2k 450Ω 10k ADJUST FOR 12.17mV AT 25°C ACROSS 450Ω LM185-2.5 TA01 OUTPUT VOLTAGE CHANGE (mV) Reverse Voltage Change 16 –55°C ≤ TA ≤ +125°C 12 8 4 0 –4 0.01 0.1 1 1...