Instructions for Using TPS54428DDAR

1. Input Capacitor Selection:

   • Use ceramic capacitors with X7R or X5R dielectric for stable operation.
   • Minimum capacitance of 10 μF is recommended.
   • Place the input capacitor as close as possible to the VIN and GND pins.

2. Output Capacitor Selection:

   • Use ceramic capacitors with X7R or X5R dielectric for optimal performance.
   • Minimum capacitance of 10 μF is recommended.
   • Place the output capacitor as close as possible to the VOUT and GND pins.

3. Inductor Selection:

   • Choose an inductor with a saturation current rating higher than the maximum output current.
   • Inductance value should be between 1 μH and 4.7 μH for typical applications.
   • Ensure the inductor has low DC resistance (DCR) to minimize power loss.

4. Setting the Output Voltage:

   • The output voltage is set by the external resistor divider connected to the FB pin.
   • Use the formula ( V_ = V_ times left(1 + fracright) ), where ( V_ = 0.8V ).

5. Setting the Switching Frequency:

   • The switching frequency can be adjusted using an external resistor connected to the RT pin.
   • Use the formula ( f_ = frac{1.1 times 10^6} ) to determine the resistor value.

6. Thermal Management:

   • Ensure adequate heat dissipation by providing a good thermal path from the exposed pad to the PCB.
   • Use a thermal vias under the exposed pad to transfer heat to the bottom layer of the PCB.

7. Layout Considerations:

   • Keep the high-current paths (VIN to inductor, inductor to VOUT) as short as possible.
   • Use wide traces for high-current paths to reduce resistance and inductance.
   • Place the compensation components (CFF, RFF, COUT) close to the respective pins to minimize parasitic effects.

8. Power-Up Sequence:

   • Ensure that the input voltage rises above the under-voltage lockout threshold before the device starts switching.
   • The device will start switching when VIN is above 4.5V.

9. Shutdown Operation:

   • To shut down the device, pull the EN pin low.
   • The device will enter a low-power state with minimal quiescent current.

10. Protection Features:

    • The device includes overcurrent protection, thermal shutdown, and undervoltage lockout.
    • These features help protect the device and the system from damage under fault conditions.