BTS3050TF Datasheet, PDF (15/39 Pages) Infineon Technologies AG – Smart Low-Side Power Switch

HITFET - BTS3050TF
Smart Low-Side Power Switch
Protection Functions
6
Protection Functions
The device provides embedded protection functions. Integrated protection functions are designed to prevent
IC destruction under fault conditions described in the datasheet. Fault conditions are considered as “outside”
normal operation. Protection functions are not designed for continuous repetitive operation.
6.1
Over Voltage Clamping on OUTput
The BTS3050TF is equipped with a voltage clamp circuitry that keeps the drain-source (OUT to GND) voltage
V_DS at a certain level V_OUT(CLAMP). The over voltage clamping is overruling the other protection functions. Power
dissipation has to be limited to not exceed the maximum allowed junction temperature.
This function is also used in terms of inductive clamping. Please see also Chapter 5.3.1 for more details.
6.2
Thermal Protection
The device is protected against over temperature due to overload and / or bad cooling conditions. To ensure
this a temperature sensor is located in the power MOSFET.
The BTS3050TF has a thermal protection function with automatic restart. After the device has switched off due
to over temperature the device will stay off until the junction temperature has dropped down below the
thermal hysteresis “Thermal Protection” on Page 15.
IN
5V
Thermal shutdown
Thermal restart
0V
t
T_j
TJ(SD )
ΔT _{J(SD)_HYS}
t
VOUT
VBAT
Figure 14 Thermal protective switch OFF scenario with thermal restart
t
Thermal _ fault_ restart.emf
6.3
Short Circuit Protection / Current limitation
The condition short circuit is an overload condition to the device. If the load current reaches the limitation
value of I_L(LIM) the device limits the current and starts heating up. When the thermal shutdown temperature is
reached, the device turns off.
The time from the beginning of current limitation until the over temperature switch off depends strongly on
the cooling conditions.
If input is still high, the device will turn on again after the measured temperature has dropped below the
thermal hysteresis.
Figure 15 shows this simplified behavior.
Datasheet
15
Rev. 1.0
2016-06-01