SLVSGG6B april 2022 – june 2023 TPS25981
PRODUCTION DATA
During hot-plug events or while trying to charge a large output capacitance at start-up, there can be a large inrush current. If the inrush current is not managed properly, it can damage the input connectors and cause the system power supply to droop leading to unexpected restarts elsewhere in the system. The inrush current during turn-on is directly proportional to the load capacitance and rising slew rate. Equation 3 can be used to find the slew rate (SR) required to limit the inrush current (IINRUSH) for a given load capacitance (COUT):
A capacitor can be connected to the dVdt pin to control the rising slew rate and lower the inrush current during turn on. Use Equation 4 to calculate the required CdVdt capacitance to produce a given slew rate.
The fastest output slew rate is achieved by leaving the dVdt pin open.
For CdVdt > 10 nF, TI recommends to add a 100-Ω resistor in series with the capacitor on the dVdt pin.