INA121U/2K5 datasheet by Texas Instruments

INA121U/2K5 Frequently Asked Questions (FAQs)

• What is the maximum input voltage that the INA121U/2K5 can handle?
  The INA121U/2K5 can handle input voltages up to ±650mV, but it's recommended to keep the input voltage within ±500mV to ensure accurate measurements.
• How do I choose the correct gain resistor for my application?
  The gain resistor (Rg) should be chosen based on the desired gain and the input voltage range. A smaller Rg value results in higher gain, but may also increase noise. A larger Rg value results in lower gain, but may improve noise performance. Consult the datasheet for a gain resistor selection table.
• What is the purpose of the REF pin, and how do I use it?
  The REF pin is a reference voltage input that allows the INA121U/2K5 to provide a ratiometric output. Connect the REF pin to a stable voltage reference (e.g., a voltage regulator output) to improve the amplifier's accuracy and reduce temperature drift.
• How do I layout the PCB to minimize noise and ensure accurate measurements?
  Keep the input traces as short as possible, and use a ground plane to reduce noise. Place the INA121U/2K5 close to the input signal source, and use a low-impedance path for the input signals. Avoid routing digital signals near the analog input traces.
• What is the typical settling time of the INA121U/2K5, and how does it affect my application?
  The typical settling time of the INA121U/2K5 is around 10μs. This means that the amplifier takes approximately 10μs to settle to its final output value after a step change in the input signal. Ensure that your application allows for sufficient settling time to ensure accurate measurements.