TERMINOLOGY
Temperature Coefficient
The change of output voltage with respect to operating temperature
changes normalized by the output voltage at 25°C. This parameter
is expressed in ppm/°C and can be determined by
TCV O
[ppm/°C
]
=
VO
VO (T2 )
(25°C)
–
×
VO (T1 )
(T2 –T1
)
× 10 6
(1)
where:
VO (25°C) is VO at 25°C.
VO (T1) is VO at Temperature 1.
VO (T2) is VO at Temperature 2.
Line Regulation
The change in output voltage due to a specified change in input
voltage. This parameter accounts for the effects of self-heating.
Line regulation is expressed in either percent per volt, parts-per-
million per volt, or microvolts per volt change in input voltage.
Load Regulation
The change in output voltage due to a specified change in load
current. This parameter accounts for the effects of self-heating.
Load regulation is expressed in either microvolts per milliampere,
parts-per-million per milliampere, or ohms of dc output resistance.
ADR391/ADR392/ADR395
Long-Term Stability
Typical shift of output voltage at 25°C on a sample of parts
subjected to a test of 1000 hours at 25°C.
ΔVO = VO(t0) − VO(t1)
ΔVO[ppm]
=
⎜⎜⎝⎛
VO
(t0 ) − VO
VO (t0 )
(t1)
×106
⎟⎟⎠⎞
(2)
where:
VO (t0) is VO at 25°C at Time 0.
VO (t1) is VO at 25°C after 1000 hours operation at 25°C.
Thermally Induced Output Voltage Hysteresis
The change of output voltage after the device cycles through
the temperatures from +25°C to –40°C to +125°C and back to
+25°C. This is a typical value from a sample of parts put through
such a cycle.
VO_HYS = VO(25°C) − VO_TC
(3)
VO _ HYS[ppm] =
VO (25o C) − VO _TC
VO (25o C)
× 10 6
(4)
where:
VO (25°C) is VO at 25°C.
VO_TC is VO at 25°C after a temperature cycle from +25°C to
−40°C to +125°C and back to +25°C.
Rev. H | Page 13 of 20