JAJSFQ6E March 2014 – July 2018 TPS92601-Q1 , TPS92602-Q1
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
The circuit uses a low-forward-voltage-drop Schottky diode as a rectifier diode to reduce power dissipation and improve efficiency. Use 80% derating for the diode on VOUTx to allow for ringing on the switch node. Equation 58 gives the rectifier-diode minimum reverse-breakdown voltage.
The diode must have a reverse-breakdown voltage greater than 45 V. Equation 59 and Equation 60 estimate the rectifier diode peak and average currents.
For this design, average current is 1 A and peak current is 3.44 A.
Equation 61 estimates the power dissipation in the diode.
For this design, the maximum power dissipation is estimated as 0.5 W. After reviewing 45-V and 60-V Schottky diodes, the selection is the 30BQ060PbF diode, Schottky, 60 V, 3 A, SMC. This diode has a forward voltage drop of 0.5 V at 1 A, so the conduction power dissipation is approximately 500 mW, less than half its rated power dissipation.