L7981 datasheet by STMicroelectronics

L7981 Frequently Asked Questions (FAQs)

• What is the maximum input voltage that the L7981 can handle?
  The L7981 can handle input voltages up to 45V, but it's recommended to keep the input voltage below 40V for reliable operation.
• How do I choose the right output capacitor for the L7981?
  The output capacitor should have a minimum capacitance of 10uF and an ESR (Equivalent Series Resistance) of less than 1 ohm. A ceramic or tantalum capacitor with a voltage rating of at least 2x the output voltage is recommended.
• Can I use the L7981 in a high-temperature environment?
  The L7981 is rated for operation up to 150°C, but the maximum junction temperature (TJ) should not exceed 125°C. Ensure proper thermal design and heat sinking to maintain a safe operating temperature.
• How do I calculate the power dissipation of the L7981?
  Power dissipation (PD) can be calculated using the formula: PD = (VIN - VOUT) x IOUT + (VIN x IQ), where IQ is the quiescent current. Ensure the PD is within the recommended limit of 1.5W for the L7981.
• Is the L7981 suitable for automotive applications?
  The L7981 is not AEC-Q100 qualified, so it's not recommended for automotive applications. Instead, consider using an automotive-grade voltage regulator from STMicroelectronics, such as the L4940 or L4941.