SLVSI26 July 2026 TPS1HC03-Q1
PRODMIX
When designing systems with both capacitive and DC loads on the same channel, it is important to consider the combined thermal impact:
Thermal Budget Consumption: Any DC load connected in parallel with a capacitive load consumes part of the thermal budget of the device. The power dissipation from the DC load (I²R) generates heat that raises the baseline temperature of the power FET.
Reduced Capacitive Charging Capability: With a power dissipation across FET to DC load, there is a reduction in the margin between operating temperature and the thermal shutdown threshold. This effectively decreases the maximum capacitance that can be safely charged without triggering thermal shutdown.
Accelerated Thermal Shutdown: The combined heating effect of DC load current and capacitive charging current can accelerate the onset of thermal shutdown. This can cause the device to enter the retry mechanism earlier and more frequently during capacitive charging.
Design Considerations: When both load types require simultaneous support:
Select a more conservative (higher) RLIM value to reduce the current limit
Provide adequate PCB copper area for improved thermal dissipation
For critical applications, consider using separate channels for DC and capacitive loads
For more information on driving inductive or capacitive loads, reference TI's How To Drive Resistive, Inductive, Capacitive, and Lighting Loads application note.