DocID026041 Rev 1

13/24

CS70

Parameter definitions

24

5

Parameter definitions

5.1

Common-mode rejection ratio (CMR)

The common-mode rejection ratio (CMR) measures the ability of the current-sensing

amplifier to reject any DC voltage applied on both inputs Vp and Vm. The CMR is referred

back to the input so that its effect can be compared with the applied differential signal. The

CMR is defined by the formula:

5.2

Supply voltage rejection ratio (SVR)

The supply-voltage rejection ratio (SVR) measures the ability of the current-sensing

input so that its effect can be compared with the applied differential signal. The SVR is

defined by the formula:

5.3

The input offset voltage is defined as the intersection between the linear regression of the

calculated with the following formula.

CMR

20

–

V

out

V

icm

Av



----------------------------

log



=

SVR

20

–

V

out

V

CC

Av



---------------------------

log



=

V

os

V

sense1

V

sense1

V

sense2

–

V

out1

V

out2

–

------------------------------------------------ V

out1







–

=