Microchip Technology ARD00354 Data Sheet
© 2011 Microchip Technology Inc.
DS25073A-page 9
MCP6N11
1.4
DC Test Circuits
1.4.1
INPUT OFFSET TEST CIRCUIT
is used for testing the INA’s input offset
errors and input voltage range (V
E
, V
IVL
and V
IVH
; see
and
). U
2
is part of a control loop that forces V
OUT
to equal V
CNT
; U
1
can be set to any bias point.
FIGURE 1-6:
Test Circuit for Common
Mode (Input Offset).
When MCP6N11 is in its normal range of operation, the
DC output voltages are (where V
DC output voltages are (where V
E
is the sum of input
offset errors and g
E
is the gain error):
EQUATION 1-1:
gives the recommended R
F
and R
G
values
for different G
MIN
options.
1.4.2
DIFFERENTIAL GAIN TEST CIRCUIT
error, non-linearity and input voltage range (g
E
, INL
DM
,
V
DML
and V
DMH
; see
). R
F
and R
G
are 0.01% for
accurate gain error measurements.
FIGURE 1-7:
Test Circuit for Differential
Mode.
The output voltages are (where V
E
is the sum of input
offset errors and g
E
is the gain error):
EQUATION 1-2:
To keep V
REF
, V
FG
and V
OUT
within their ranges, set:
EQUATION 1-3:
shows the recommended R
F
and R
G
. They
produce a 10 k
Ω load; V
L
can usually be left open.
TABLE 1-5:
SELECTING R
F
AND R
G
G
MIN
(V/V)
Nom.
R
F
(
Ω)
Nom.
R
G
(
Ω)
Nom.
G
DM
(V/V)
Nom.
G
DM
V
OS
(±V)
Max.
BW
(kHz)
Nom.
Nom.
1
100k
499
201.4
0.60
2.5
2
0.40
5.0
5
100k
100
1001
0.85
2.5
10
0.50
5.0
100
0.35
35
R
L
V
CM
100 nF
V
DD
2.2 µF
V
REF
V
L
12.7 k
Ω
V
M
100 nF
C
CNT
U
1
MCP6N11
U
2
MCP6H01
V
CNT
63.4 k
Ω
R
G
R
F
R
CNT
63.4 k
Ω
V
OUT
10 nF
1 k
Ω
1 k
Ω
G
DM
1
R
F
R
G
⁄
+
=
V
OUT
V
C NT
=
V
M
V
REF
G
DM
1
g
E
+
(
)V
E
+
=
TABLE 1-6:
SELECTING R
F
AND R
G
G
MIN
(V/V)
Nom.
R
F
(
Ω)
Nom.
R
G
(
Ω)
Nom.
G
DM
(V/V)
Nom.
1
0
Open
1.000
2
4.99k
4.99k
2.000
5
8.06k
2.00k
5.030
10
9.09k
1.00k
10.09
100
10.0k
100
101.0
R
L
6.34 k
Ω
1 k
Ω
1 k
Ω
V
CM
+ V
DM
/2
+
100 nF
V
OUT
R
F
R
G
V
M
–
100 nF
V
DD
2.2 µF
6.34 k
Ω
V
REF
V
FG
V
L
V
CM
– V
DM
/2
0.01%
0.01%
U
1
MCP6N11
G
DM
1
R
F
R
G
⁄
+
=
V
M
V
OUT
V
REF
–
=
V
OUT
V
REF
G
DM
1
g
E
+
(
) V
DM
V
E
+
(
)
+
=
G
DM
1
g
E
+
(
) V
DM
V
E
+
(
)
=
V
REF
V
DD
G
DM
V
DM
–
(
) 2
⁄
=