Datasheet

ADR5040/ADR5041/ADR5043/ADR5044/ADR5045 Data Sheet
Rev. B | Page 10 of 16
TERMINOLOGY
Temperature Coefficient
The change in output voltage with respect to operating temperature
changes. It is normalized by an output voltage of 25°C. This
parameter is expressed in ppm/°C and is determined by the
following equation:
( ) ( )
( ) ( )
6
10
C25C
ppm
×
−×°
−
=






°
12
UT
O
1
OUT
2
OUT
OUT
TTV
TVTV
TCV
(1)
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.
Thermal Hysteresis
The change in output voltage after the device is cycled through
temperatures ranging from +25°C to −40°C, then to +125°C, and
back to +25°C. This is common in precision reference and is
caused by thermal-mechanical package stress. Changes in envi-
ronmental storage temperature, board mounting temperature, and
the operating temperature are some of the factors that can
contribute to thermal hysteresis. The following equation
expresses a typical value from a sample of parts put through
such a cycle:
( )
[ ]
( )
( )
6
]
]
]]
10
C25
C25
ppm
C25
×
°
−°
=
−°=
OUT
TCOUTOUT
HYSOUT
TCOUTOUTHYSOUT
V
VV
V
VVV
(2)
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, then to +125°C, and back to +25°C.