The TPS16530 device features accurate overload current limiting and fast short circuit protection feature. The device supports a pulse current up to 9A (2 × I_OL) for transient loads. Table 8-1 describes the overload response of TPS16530 device.

The power dissipation across the device during this operation will be [(V_IN – V_OUT) × I_OL] for I_OUT < 2 × I_OL or [(V_IN – V_OUT) × 2 × I_OL] for 2 × I_OL < I_OUT < 3 × I_OLand this could heat up the device and eventually enter into thermal shutdown.

For current limit of I_OL, the maximum duration for current limiting is t_{CL_ILIM(dly)}, 162 msec (typical). For current limit of 2 × I_OL, the maximum duration for current limiting is t_CB(dly), 25 msec (typical) .

If the thermal shutdown occurs before this time the internal FET turns OFF and the device operates either in auto-retry or latch off mode based on MODE pin configuration in Table 8-2. Set the current limit using Equation 4.

where

• I_(OL) is the overload current limit in Ampere
• R_(ILIM) is the current limit resistor in kΩ

During the overload current limiting, if the overload condition exists for more than t_{CL_ILIM_FLT(dly)}, 1.3 msec (typical), the FLT asserts to warn of impending turnoff of the internal FETs due to the subsequent thermal shutdown event or due to t_{CL_ILIM(dly)} timer expiry. The FLT signal remains asserted until the fault condition is removed and the device resumes normal operation. Figure 8-4 shows the device behavior in case of overload event. The device provides a pulse current of 7 A for a duration of 25 ms and then turns off the internal FET due to thermal shutdown before the expiry of t_{CL_ILIM(dly)}.

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.

The TPS16530 device 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.