link to page 9 link to page 9 ADR380/ADR381 TERMINOLOGY Temperature CoefficientLong-Term Stability The change of output voltage over the operating temperature A typical shift in output voltage over 1000 hours at a controlled change and normalized by the output voltage at 25°C, expressed temperature. Figure 24 and Figure 25 show a sample of parts in ppm/°C. The equation follows: measured at different intervals in a controlled environment of 50°C for 1000 hours. V (T ) OUT 2 −V (T ) OUT 1 6 TCV [ppm/ C OUT ° ]= 10 × Δ OUT V =V (t ) OUT 0 − V (t ) OUT 1 OUT V (25°C)×( 2 T −T ) 1 V (t ) OUT 0 − V (t ) OUT 1 6 where: ΔV [ppm] O = ×10 UT V t V ( ) OUT 0 OUT (25°C) = VOUT at 25°C. VOUT (T1) = VOUT at Temperature 1. where: VOUT (T2) = VOUT at Temperature 2. VOUT (t0) = VOUT at Time 0. V Line Regulation OUT (t1) = VOUT after 1000 hours of operation at a controlled The change in output voltage due to a specified change in input temperature. voltage. It includes the effects of self-heating. Line regulation is Note that 50°C was chosen because most applications run at a expressed in either percent per volt, parts-per-million per volt, higher temperature than 25°C. or microvolts per volt change in input voltage. Thermal HysteresisLoad Regulation The change of output voltage after the device is cycled through The change in output voltage due to a specified change in load temperature from +25°C to −40°C to +85°C and back to +25°C. current. It includes the effects of self-heating. Load regulation is This is a typical value from a sample of parts put through such expressed in either microvolts per milliampere, parts-per-million a cycle. per milliampere, or ohms of dc output resistance. VOUT HYS =VO (25°C)−V _ UT OUT _ TC V 25 ( C OUT ° )−VOUT _ TC 6 V [ppm] OUT HYS = ×10 _ VOUT (25°C) where: VOUT (25°C) = VOUT at 25°C. VOUT_TC = VOUT at 25°C after a temperature cycle from +25°C to −40°C to +85°C and back to +25°C. Rev. C | Page 10 of 16 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION PIN CONFIGURATION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ADR380 ELECTRICAL CHARACTERISTICS ADR381 ELECTRICAL CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION DEVICE POWER DISSIPATION CONSIDERATIONS INPUT CAPACITOR OUTPUT CAPACITOR APPLICATIONS INFORMATION STACKING REFERENCE ICs FOR ARBITRARY OUTPUTS A NEGATIVE PRECISION REFERENCE WITHOUT PRECISION RESISTORS PRECISION CURRENT SOURCE PRECISION HIGH CURRENT VOLTAGE SOURCE OUTLINE DIMENSIONS ORDERING GUIDE