BTS7040-1EPA
PROFET™ +2 12V
Power Stages
7.2.2
Switching Inductive Loads
When switching OFF inductive loads with high-side switches, the voltage VOUT drops below ground potential,
because the inductance intends to continue driving the current. To prevent the destruction of the device due
to overvoltage, a voltage clamp mechanism is implemented. The clamping structure limits the negative
output voltage so that VDS = VDS(CLAMP). Figure 17 shows a concept drawing of the implementation. The
clamping structure protects the device in all operation modes listed in Chapter 6.1.
VS
High-side
Channel
VS
VDS
VSIS(CLAMP)
VDS(CLAMP)
IS
IL
VOUT
VS(CLAMP)
OUT
GND
L,
RL
IL
PowerStage_Clamp_INTDIO_1CH.emf
Figure 17 Output Clamp concept
During demagnetization of inductive loads, energy has to be dissipated in BTS7040-1EPA. The energy can be
calculated with Equation (7.1):
RL IL
ln 1 – ------------------------------------------- + IL
VS – VDS(CLAMP)
-------------------------------------------
RL
L
RL
æ
ö
------
E = VDS(CLAMP)
(7.1)
è
ø
VS – VDS(CLAMP)
The maximum energy, therefore the maximum inductance for a given current, is limited by the thermal design
of the component.
Data Sheet
22
Rev. 1.10
2020-12-14
INFINEON [ Infineon ]
