1. Overview & Purpose

️· The MP2560 is a step-down (buck) converter.
️· It's designed to efficiently convert a higher voltage input to a lower voltage output.

2. Key Components & Selection

️· Inductor:
- Important for supplying constant current.
- Larger inductance reduces ripple.
- Formula for inductance calculation: `L = (Vout * f * V)/ (ΔI * (Vin-Vout))`
- Peak inductor current: `I_peak = I_load + 2 * Vf/L`
- Table 1 provides a selection guide for inductors from various manufacturers.
️· Output Rectifier Diode:
- Use a Schottky diode to minimize losses (due to voltage and recovery time).
- Voltage rating > maximum input voltage.
- Current rating > maximum load current.
- Table 2 provides a diode selection guide.
️· Input Capacitor:
- Essential to supply AC current to the converter.
- Use low ESR capacitors (ceramic preferred).
- RMS current rating > half the maximum load current.
️· Feedback Resistors (R1 & R2):
- Used to set the output voltage.
- Formula for output voltage: `V_out = V_fb * (R1 + R2) / R2`
- R2 should be kept below 40kΩ to absorb small currents.
- Formula for R1: `R1 = 25 * (V_out - 0.8)kΩ`

3. Operating Frequency & Oscillator

️· The switching frequency is set by an external resistor (R_freq) connected from the FREQ pin to ground.
️· Formula for R_freq: `R_freq (in kΩ) = 180000 / f (in kHz) - 1.1`

4. Other Important Notes

️· Timer Hold-Off: An internal timer holds the power MOSFET off for about 50µs during startup.
️· Shutdown: The converter can shut down due to: EN low, VIN low, or thermal shutdown.
️· Soft-Start: The internal soft-start circuit gradually ramps up the output voltage.