OPA277 Datasheet, PDF (9/9 Pages) Burr-Brown (TI) – High Precision OPERATIONAL AMPLIFIERS

V+
1/2
OPA2277
R–∆R
V₁
Load
Cell
R+∆R
V₂
R+∆R
R–∆R
V–
V+
1/2
OPA2277
V–
R₂
R₁
V_OUT
=
(V₁
–
V₂)(1
+
R₂
R₁
)
R₂
R₁
For integrated solution see: INA126, INA2126 (dual)
INA125 (on-board reference)
INA122 (single-supply)
FIGURE 3. Load Cell Amplifier.
Type J
I_REG ∼ 1mA
5V
50Ω
V+
1/2
OPA2277
R_F
10kΩ
R
412Ω
R_F
10kΩ
1kΩ
1/2
OPA2277
V–
25Ω _{RCM = 1250Ω}
12
V_LIN ¹
13 _VI+N ^IR1
4
R_G
14
I_R2
11
V_REG
10
V+
R_G
1250Ω
XTR105
B9
3 _RG
2 ^VI–N
I_RET
6
E
8
I_O
7
I_O
=
4mA +
(V_I+N
–
V_I–N)
40
R_G
0.01µF
(G = 1 + ^2RF = 50)
R
FIGURE 4. Thermocouple Low Offset, Low Drift Loop Measurement with Diode Cold Junction Compensation.
®
9
OPA277, 2277, 4277