BTS428L2 Datasheet, PDF (8/12 Pages) Infineon Technologies AG – Smart High-Side Power Switch One Channel: 60mΩ Status Feedback

BTS428L2
GND disconnect with GND pull up
IN
2
ST
4
3
Vbb
PROFET
GND
1
OUT
5
Vbb
VIN VST
VGND
Any kind of load. If VGND > VIN - VIN(T+) device stays off
Due to VGND >0, no VST = low signal available.
Inductive Load switch-off energy
dissipation
E _bb
E _AS
IN
Vbb
PROFET ^OUT
=
ST
GND
L
{Z _{L RL}
ELoad
EL
ER
Vbb disconnect with energized inductive
load
3
high
IN
Vbb
2
ST
4
PROFET
GND
OUT
5
1
Energy stored in load inductance:
E_L = ^1/2·L·I^2L
While demagnetizing load inductance, the energy
dissipated in PROFET is
∫ ^{EAS= Ebb + EL - ER= VON(CL)·iL(t) dt,}
with an approximate solution for R_L > 0 Ω:
E_AS=
2I^L·R^{· L}_L^·(Vbb
+
|V_OUT(CL)|)·
ln
(1+
I_L·R_L
|V_OUT(CL)|
)
Vbb
For inductive load currents up to the limits defined by ZL
(max. ratings and diagram on page 8) each switch is
protected against loss of Vbb.
Consider at your PCB layout that in the case of Vbb dis-
connection with energized inductive load all the load current
flows through the GND connection.
Maximum allowable load inductance for
a single switch off
L = f (I_L ); T_j,start = 150°C,T_C = 150°C const.,
V_bb = 12 V, R_L = 0 Ω
Z_L [mH]
1000
100
10
1
0.1
2
7
12
17
I_L [A]
Semiconductor Group
Page 8
1999-Feb-26