JAJSFP5E July 2018 – February 2022 REF2025 , REF2030 , REF2033 , REF2041
PRODUCTION DATA
The differential amplifier used for this design should have the following features:
For this design, a current-shunt monitor (INA213) is used. The INA21x family topology is shown in Figure 10-3. The INA213B specifications can be found in the INA213 product data sheet.
The INA213B is an excellent choice for this application because all the required features are included. In general, instrumentation amplifiers (INAs) do not have the input common-mode swing to ground that is essential for this application. In addition, INAs require external resistors to set their gain, which is not desirable for low-drift applications. Difference amplifiers typically have larger input bias currents, which reduce solution accuracy at small load currents. Difference amplifiers typically have a gain of 1 V/V. When the gain is adjustable, these amplifiers use external resistors that are not conducive to low-drift applications.