ADR520/ADR525/ADR530/ADR540/ADR550
Rev. E | Page 7 of 16
PARAMETER DEFINITIONS
TEMPERATURE COEFFICIENT
Temperature coefficient is defined as the change in output
voltage with respect to operating temperature changes and is
normalized by the output voltage at 25°C. This parameter is
expressed in ppm/°C and is determined by the following
equation:
6
12
12
10
)(C)25(
)()(
C
ppm
×
−×°
−
=
⎥
⎦
⎤
⎢
⎣
⎡
° TTV
TVTV
TCV
OUT
OUTOUT
O
(1)
where:
V
OUT
(T
2
) = V
OUT
at Temperature 2.
V
OUT
(T
1
) = V
OUT
at Temperature 1.
V
OUT
(25°C) = V
OUT
at 25°C.
THERMAL HYSTERESIS
Thermal hysteresis is defined as the change in output voltage
after the device is cycled through temperatures ranging from
+25°C to −40°C, then to +85°C, and back to +25°C. The
following equation expresses a typical value from a sample of
parts put through such a cycle:
6
_
_
__
10
C)25(
C)25(
[ppm]
C)25(
×
°
−°
=
−°=
OUT
ENDOUTOUT
HYSOUT
ENDOUTOUTHYSOUT
V
VV
V
VVV
(2)
where:
V
OUT
(25°C) = V
OUT
at 25°C.
V
OUT_END
= V
OUT
at 25°C after a temperature cycle from +25°C to
−40°C, then to +85°C, and back to +25°C.
