BD90640HFP-CTR - ROHM Semiconductor

BD90640HFP-CTR Frequently Asked Questions (FAQs)

• What is the recommended PCB layout for optimal thermal performance?
  ROHM recommends a 2-layer or 4-layer PCB with a thermal relief pattern on the bottom layer to improve heat dissipation. A minimum of 1 oz copper thickness is recommended for the PCB.
• How do I ensure stable operation with a high-capacitance output capacitor?
  To ensure stable operation, ROHM recommends using an output capacitor with a capacitance value between 10uF to 100uF, and an ESR (Equivalent Series Resistance) of less than 10mΩ. Additionally, a 1uF to 10uF ceramic capacitor in parallel with the output capacitor can help improve stability.
• What is the recommended input capacitor value and type for this regulator?
  ROHM recommends using a 1uF to 10uF ceramic capacitor with an X5R or X7R dielectric as the input capacitor. This helps to filter out noise and improve regulator stability.
• How do I protect the regulator from overcurrent and overheating?
  ROHM recommends using an external current sense resistor (RSENSE) to monitor the output current. Additionally, a thermal protection circuit can be implemented using a thermistor or a thermal switch to shut down the regulator in case of overheating.
• What is the recommended layout and placement for the feedback resistors?
  ROHM recommends placing the feedback resistors (R1 and R2) as close as possible to the FB pin, and using a separate analog ground plane to minimize noise coupling. The resistors should be placed on the same layer as the IC, and the traces should be as short as possible.