L4938ED datasheet by STMicroelectronics

L4938ED Frequently Asked Questions (FAQs)

• What is the maximum input voltage that can be applied to the L4938ED?
  The maximum input voltage that can be applied to the L4938ED is 26V, although the recommended maximum input voltage is 20V to ensure reliable operation.
• How do I ensure the L4938ED is stable and doesn't oscillate?
  To ensure stability, a minimum output capacitance of 10uF with an ESR (Equivalent Series Resistance) of less than 1 ohm is recommended. Additionally, the input capacitor should be at least 1uF with an ESR of less than 5 ohms.
• What is the dropout voltage of the L4938ED?
  The dropout voltage of the L4938ED is typically around 1.5V, which means the input voltage must be at least 1.5V higher than the output voltage to ensure proper regulation.
• Can I use the L4938ED in a high-temperature environment?
  The L4938ED is rated for operation up to 150°C, but the maximum junction temperature (TJ) should not exceed 125°C. Thermal derating may be necessary for high-temperature applications.
• How do I calculate the power dissipation of the L4938ED?
  The power dissipation of the L4938ED can be calculated using the formula: Pd = (Vin - Vout) x Iout, where Vin is the input voltage, Vout is the output voltage, and Iout is the output current.