SBOS893D August 2018 – June 2020 INA821
Figure 55 shows that the gain of the INA821 is set by a single external resistor (RG) connected between the RG pins (pins 1 and 8).
The value of RG is selected according to:
Table 2 lists several commonly used gains and resistor values. The 49.4-kΩ term in Equation 1 is a result of the sum of the two internal 24.7-kΩ feedback resistors. These on-chip resistors are laser-trimmed to accurate absolute values. The accuracy and temperature coefficients of these resistors are included in the gain accuracy and drift specifications of the INA821. As shown in Figure 55 and explained in more details in the Layout section, make sure to connect low-ESR, 0.1-µF ceramic bypass capacitors between each supply pin and ground, that are placed as close to the device as possible.
|DESIRED GAIN||RG (Ω)||NEAREST 1% RG (Ω)|
|2||49.4 k||49.9 k|
|5||12.35 k||12.4 k|
|10||5.489 k||5.49 k|
|20||2.600 k||2.61 k|
|50||1.008 k||1 k|