9.2.2 Detailed Design Procedure
Before the controller design begins, the power-stage design must be completed. From the power-stage design the following operating parameters are required to complete the setup procedure of the controller:
- Switching frequency (fSW)
- Maximum operating duty cycle (DMAX)
- Soft-start duration (tSS)
- Gate-drive power requirements of the external-power MOSFETs (QG(main), QG(aux))
- Bias method and voltage for steady-state operation (bootstrap or bias supply)
- Gate-drive turn-on delay (tDEL)
- Turnon input-voltage threshold (VON)
- Minimum-operating input voltage (VOFF where VIN(OFF) < VIN(on)
- Maximum-operating input voltage (VOVP)
- Overvoltage-protection hysteresis (VOVH)
- The down slope of the output-inductor current-waveform reflected across the primary-side current-sense resistor (dVL / dt)