ADR291W
Rev. 0 | Page 6 of 8
TERMINOLOGY
Line Regulation
Line regulation refers to the change in output voltage due to a
specified change in input voltage. It includes the effects of self-
heating. Line regulation is expressed as percent per volt, parts
per million per volt, or microvolts per volt change in input
voltage.
Load Regulation
The change in output voltage is due to a specified change in
load current and includes the effects of self-heating. Load
regulation is expressed in microvolts per milliampere, parts per
million per milliampere, or ohms of dc output resistance.
Long-Term Stability
Long-term stability refers to the typical shift of output voltage
at 25°C on a sample of parts subjected to a test of 1000 hours
at 125°C.
6
10ppm
0
OUT
1
OUT
0
OUT
OUT
1
OUT
0
OUTOUT
tV
tVtV
V
V
VV
where:
V
OUT
(t
0
) = V
OUT
at 25°C at Time 0.
V
OUT
(t
1
) = V
OUT
at 25°C after 1000 hours of operation at 125°C.
Temperature Coefficient
Temperature coefficient is the change of output voltage over
the operating temperature change, normalized by the output
voltage at 25°C, expressed in ppm/°C. The equation follows:
6
10
C25
Cppm/
12
OUT
1
OUT
2
OUT
O
TTV
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.
NC = No Connect
There are internal connections at NC pins that are reserved for
manufacturing purposes. Users should not connect anything at
the NC pins.
Thermally Induced Output Voltage Hysteresis
Thermally induced output voltage hysteresis is defined as the
change of output voltage after the device is cycled through
temperatures from +25°C to −40°C, then 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
C)25(
)25(
[ppm]
C)25(
OUT
OUT_TCOUT
HYSΟUT
OUT_TCOUTHYSOUT
V
VCV
V
VVV
where:
V
OUT
(25°C) = V
OUT
at 25°C.
V
OUT–TC
= V
OUT
at 25°C after temperature cycle from +25°C to
−40°C, then to +85°C, and back to +25°C.
