LM20145MH/NOPB datasheet by Texas Instruments

LM20145MH/NOPB Frequently Asked Questions (FAQs)

• What is the recommended PCB layout for optimal thermal performance?
  A good PCB layout for the LM20145MH/NOPB should prioritize thermal dissipation. Place the device near a thermal pad or a heat sink, and ensure good copper pour coverage around the device. Avoid routing high-current traces near the device, and use thermal vias to dissipate heat.
• How do I ensure stability and prevent oscillations in the output voltage?
  To ensure stability, follow the recommended component values and PCB layout guidelines. Ensure that the output capacitor has a low ESR and is placed close to the output pin. Also, add a small ceramic capacitor (e.g., 10nF) between the output and ground to filter out high-frequency noise.
• What is the maximum input voltage that can be applied to the device?
  The maximum input voltage for the LM20145MH/NOPB is 42V. Exceeding this voltage may damage the device. Ensure that the input voltage is within the recommended range to ensure reliable operation.
• How do I calculate the output voltage ripple and noise?
  The output voltage ripple and noise can be calculated using the formula: ΔVout = (Iout * ESR) / (f * Cout), where Iout is the output current, ESR is the output capacitor's equivalent series resistance, f is the switching frequency, and Cout is the output capacitance. Use this formula to estimate the output voltage ripple and noise, and adjust the component values accordingly.
• What is the recommended input capacitor value and type for this device?
  A ceramic or electrolytic capacitor with a value between 10uF to 22uF is recommended for the input capacitor. The capacitor should have a voltage rating of at least 50V and be placed close to the input pin to filter out input noise and ripple.