LTC3128IUFD#PBF - Analog Devices

LTC3128IUFD#PBF Frequently Asked Questions (FAQs)

• What is the maximum input voltage that can be applied to the VIN pin?
  The maximum input voltage that can be applied to the VIN pin is 18V, but it's recommended to keep it below 15V for optimal performance and to prevent damage to the internal components.
• How do I optimize the inductor selection for the LTC3128?
  To optimize the inductor selection, consider the following factors: inductance value, DC resistance, and saturation current. A good starting point is to choose an inductor with an inductance value between 1.5uH to 3.3uH, and a DC resistance of less than 100mΩ. Also, ensure the inductor can handle the peak current of the converter.
• What is the recommended PCB layout for the LTC3128?
  For optimal performance, it's recommended to follow a star-ground configuration, where the GND pins of the IC are connected to a central ground point. Keep the high-current paths (VIN, VOUT, and SW) short and wide, and avoid routing sensitive signals near the inductor or switch node. Also, use a solid ground plane to reduce noise and EMI.
• How do I adjust the output voltage of the LTC3128?
  The output voltage of the LTC3128 can be adjusted by changing the resistor divider network connected to the FB pin. The output voltage is determined by the ratio of R1 and R2, where VOUT = 0.8V x (1 + R2/R1). Choose R1 and R2 to achieve the desired output voltage, ensuring that R1 is at least 1kΩ and R2 is at least 2kΩ.
• What is the purpose of the RUN pin, and how do I use it?
  The RUN pin is an active-high enable input that allows the user to turn the converter on and off. When the RUN pin is high, the converter is enabled, and when it's low, the converter is disabled. This pin can be used to implement power sequencing, shutdown, or low-power modes in the system.