Applications that need higher steady current can use two TPS25974x devices connected in parallel as shown in Figure 9-20. In this configuration, the first device turns on initially to provide the inrush current control. The second device is held in an OFF state by driving its EN/UVLO pin low using the PG signal of the first device. After the inrush sequence is complete, the first device asserts its PG pin high and turns on the second device. The second device asserts its PG signal to indicate when it has turned on fully, thereby indicating to the system that the parallel combination is ready to deliver the full steady state current.

After in steady state, both devices share current nearly equally. There can be a slight skew in the currents depending on the part-to-part variation in the R_ON as well as the PCB trace resistance mismatch.

Figure 9-7 Two Devices Connected in Parallel for Higher Steady State Current Capability

The waveforms below illustrate the behavior of the parallel configuration during start-up as well as during steady state.

Figure 9-8 Parallel Devices Sequencing During Start-Up

Figure 9-9 Parallel Devices Load Current During Steady State and Overload