ADR121/ADR125/ADR127

Rev. B | Page 15 of 20

TERMINOLOGY

Temperature Coefficient

The change in output voltage with respect to operating

temperature change normalized by the output voltage at 25°C.

This parameter is expressed in ppm/°C and can be determined

as follows:

[]

()

( )

() (

)

6

10

C

25

C

ppm/

×

−

×

°

−

=

°

1

2

OUT

1

OUT

2

UT

O

OUT

T

T

V

T

V

T

V

TCV

(1)

where:

Line Regulation

The change in the output voltage due to a specified change

in input voltage. This parameter accounts for the effects of

self-heating. Line regulation is expressed in percent per volt,

parts-per-million per volt, or microvolts per voltage 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 microvolts per milliampere,

parts-per-million per milliampere, or ohms of dc output

resistance.

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.

( )( )

[]

()

( )

()

6

10

ppm

×

−

=

Δ

−

Δ

0

OUT

1

OUT

0

OUT

OUT

1

UT

O

0

OUT

UT

O

t

V

t

V

t

V

V

t

V

t

V

V

(2)

where:

Thermal Hysteresis

The change in output voltage after the device is cycled through

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.

(

)

TC

OUT

OUT

HYS

OUT

V

V

V

_

_

C

25

−

°

=

(3)

[]

()

()

6

_

_

10

C

25

C

25

ppm

×

°

−

°

=

OUT

TC

OUT

UT

O

HYS

OUT

V

V

V

V

where:

−40°C to +125°C and back to +25°C.