Automotive smart high side switch BSP742R test-bench: short circuit protection with current limitation

Open online SPICE simulator circuit link: atv_bp_protection_12V_BSP742R_sc.tsc

Smart High-Side Switch BSP742R
Protection Features: Short circuit with current limitation

Thermal model description:
THERMALMODEL = 1: 1S0P PCB 600mm2
THERMALMODEL = 2: 2S2P no vias
THERMALMODEL = 3: 2S2P vias

The BSP742R is high side power switch with integrated vertical power FET,
providing embedded protection and diagnostic functions.

This circuit demonstrates the short circuit with current limitation and
overtemperature shutdown with restart features of the BSP742R. Many
other switches provide similar protection features.

Once short circuit condition occurs, the load current increases dramatically and
the instantaneous power in the switch is maintained at a safe value by limiting
the current to the maximum current allowed in the switch IL(SCp) (see datasheet).

Considering thermal behavior (choose thermal model 1....3), the junction
temperature is also rising quickly. Once the thermal shutdown protection is
triggered, the device shuts down autonomously with restart. It shuts down
and restart continuously if the temperature is higher than the trigger value.

{1. click here to set circuit parameters}
{2. click on "Run" to calculate components}
{3. click on "OK" and Simulate Transient }

{Supply Voltage [V] }
Vbb:= 20 {Use 5....34}

{Short circuit on/off trigger time [s] }
tSC_on:= 10m
tSC_off:= 20m

{Thermal model number: }
THERMALMODEL:= 1 {use 1 .... 3}