Datasheet

TSC1031 Parameter definitions
Doc ID 16875 Rev 2 13/26
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 V
p
and V
m
. 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
amplifier to reject any variation of the supply voltage V
CC
. The SVR is referred back to the
input so that its effect can be compared with the applied differential signal. The SVR is
defined by the formula:
5.3 Gain (Av) and input offset voltage (V
os
)
The input offset voltage is defined as the intersection between the linear regression of the
V
out
vs. V
sense
curve with the X-axis (see Figure 17.). If V
out1
is the output voltage with
V
sense
=V
sense1
and V
out2
is the output voltage with V
sense
=V
sense2
, then V
os
can be
calculated with the following formula.
CMR 20–
ΔV
out
ΔV
icm
Av⋅
------------------------------log⋅=
SVR 20–
ΔV
out
ΔV
CC
Av⋅
------------------------------log⋅=
V
os
V
sense1
V
sense1
V
sense2
–
V
out1
V
out2
–
------------------------------------------------
V
out1
⋅
⎝⎠
⎛⎞
–=