8.3.6.1 Output-Current Derating Topology
Voltage at the DERATE pin, V(DERATE), is used for output-current-derating control. To set the V(DERATE) voltage, a resistor divider on supply voltage VIN is typically used for supply overvoltage protection.
- When VDERATE is lower than V(DERATE_FULL), output current derating is not enabled; thus, output-current derating ratio k(DERATE_Dim) is at 100%.
- When VDERATE is higher than V(DERATE_HALF), output current derating is limited to 50%; thus, output-current derating ratio k(DERATE_Dim) is at 50%.
- When V(DERATE) is between V(DERATE_FULL) and V(DERATE_HALF), the output-current-derating ratio is negatively proportional to V(DERATE) with 32 steps. Current derating is rounded to the next-lower step. The output-current-derating ratio can be calculated using the following equations.
Equation 8. ![TPS92830-Q1 TPS92830-Q1 Equation_06_SLIS178.gif](/ods/images/JAJSE12A/Equation_06_SLIS178.gif)
Equation 9. ![TPS92830-Q1 TPS92830-Q1 Equation_07_SLIS178.gif](/ods/images/JAJSE12A/Equation_07_SLIS178.gif)