SLVSE94G September 2018 – June 2024
PRODUCTION DATA
TPS26631, TPS26633, TPS26635, and TPS26637 after the start-up and with PGOOD high, if the load current exceeds IOL, then an internal fixed tCB(dly), 25.5 ms (typical) timer starts. During this time, the device passes through the over current demanded by the load not more than 2 × IOL above which the device regulates at 2 × IOL. After tCB(dly) time, the device regulates the current at IOL. The power dissipation across the device during this operation is (VIN – VOUT) × IOL, and this can heat up the device and eventually enter into thermal shutdown. The maximum duration for the internal FET in current regulation is tCL_PLIM(dly). The subsequent operation is based on the MODE setting (either auto-retry or latch-off) in Table 8-1.
The 2 × I(OL) pulse current support is activated only after PGOOD goes high. If PGOOD is in low state such as during start-up operation or during auto-retry cycles, the 2 × I(OL) pulse current support is not activated and the device limits the current at I(OL) level.
Figure 8-14 and Figure 8-15 illustrate overload current limiting performance.
VIN_SYS = 24 V | MODE connected to GND (Auto-Retry) | RILIM = 9 kΩ |
VIN_SYS = 24 V | MODE connected to GND (Auto-Retry) | RILIM = 9 kΩ |
The TPS2663x devices feature ILIM pin short and open fault detection and protection. The internal FET is turned OFF when ILIM pin is detected short or open to GND and it remains OFF till the ILIM pin fault is removed.
Refer to Figure 7-2 for more information on tCB(dly) and tCL_PLIM(dly) parameter measurement information.