13.5V low side inductive load over voltage clamping protection with HITFET™ BTF3050TE

Open online SPICE simulator circuit link: atv_bp_13.5V_low_side_BTF3050TE_protection_OV_clamp.tsc

HITFET™ Automotive Smart Low-Side Switch BTF3050TE:
Protection Features - Inductive Load Output Clamping

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

{Supply voltage [V]}
Vs:= 13.5 {use 5 ... 28}
{Load inductance [H]}
L_load:= 5m {use 1m ... 50m}
{The max. inductance is current related.}
{see datasheet Figure 13}

{Switching slew rate adjustment: }
R_SRP:= 58k {use 5k ... 70k}
{normal operation, see datasheet section 5.5}

{Thermal model number: }
ThermalModel:= 1 {use 1 ... 4}

The BTF3050TE is a 50 mOhm single channel Smart Low-Side Power Switch providing embedded
protective functions. Infineon’s HITFET™ protected low-side switches drive resistive, capacitive as
well as inductive loads. The target applications of the BTF3050TE are replay replacement, small
motors and solenoids.

This circuit demonstrates its protection feature output clamping for inductive load during switching off.
Many other HITFET™ devices provide similar protection features. During switching off of an inductive
load, the internal circuit clamps the Vds (Pin OUT to GND) of the internal MOSFET to VOUT(CLAMP),
to prevent unwanted high voltage.

The over voltage clamping overrules the other protection features. Power dissipation has to be limited
to keep the maximum allowed junction temperature.

Thermal model discription:
THERMAL_MODEL=1: 1s0p PCB 300\e(mm,2)
THERMAL_MODEL=2: 1s0p PCB 600\e(mm,2)
THERMAL_MODEL=3: 1s0p PCB min. footprint
THERMAL_MODEL=4: 2s2p PCB