Datasheet

ADR380/ADR381
Rev. C | Page 10 of 16
TERMINOLOGY
Temperature Coefficient
The change of output voltage over the operating temperature
change and normalized by the output voltage at 25°C, expressed
in ppm/°C. The equation follows:
6
10
)(
)()(
]Cppm/[ ×
−×°
−
=°
12
OUT
1
OUT
2
OUT
OUT
TTC)(25V
TVTV
TCV
where:
V
OUT
(25°C) = V
OUT
at 25°C.
V
OUT
(T
1
) = V
OUT
at Temperature 1.
V
OUT
(T
2
) = V
OUT
at Temperature 2.
Line Regulation
The change in output voltage due to a specified change in input
voltage. It includes 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. It includes 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.
Long-Term Stability
A typical shift in output voltage over 1000 hours at a controlled
temperature. Figure 24 and Figure 25 show a sample of parts
measured at different intervals in a controlled environment of
50°C for 1000 hours.
6
10
)(
)()(
]ppm[
)()(
×
−
=Δ
−=Δ
0
UT
O
1
OUT
0
OUT
UT
O
1
UT
O
0
OUTOUT
tV
tVtV
V
tVtVV
where:
V
OUT
(t
0
) = V
OUT
at Time 0.
V
OUT
(t
1
) = V
OUT
after 1000 hours of operation at a controlled
temperature.
Note that 50°C was chosen because most applications run at a
higher temperature than 25°C.
Thermal Hysteresis
The change of output voltage after the device is cycled through
temperature from +25°C to −40°C to +85°C and back to +25°C.
This is a typical value from a sample of parts put through such
a cycle.
6_
_
__
10
)C25(
]ppm[ ×
°
−°
=
−°=
C)(25V
VV
V
VC)(25VV
OUT
TCOUTOUT
HYSOUT
TCOUT
UT
O
HYSOUT
where:
V
OUT
(25°C) = V
OUT
at 25°C.
V
OUT_TC
= V
OUT
at 25°C after a temperature cycle from +25°C to
−40°C to +85°C and back to +25°C.