Datasheet

2006-03-09
Page 8
ISP 762 T
V
bb
disconnect with charged inductive
load
PROFET
V
IN
OUT
GND
bb
V
bb
high
GND disconnect
PROFET
V
IN
OUT
GND
bb
V
bb
V
IN
V
GND
Inductive Load switch-off energy
dissipation
PROFET
V
IN
OUT
GND
bb
=
E
E
E
E
AS
bb
L
R
E
Load
R
L
L
{
L
Z
GND disconnect with GND pull up
PROFET
V
IN
OUT
GND
bb
V
bb
V
GND
V
IN
Energy stored in load inductance: E
L
= ½ * L * I
L
2
While demagnetizing load inductance,
the enérgy dissipated in PROFET is
E
AS
= E
bb
+ E
L
- E
R
= V
ON(CL)
* i
L
(t) dt,
with an approximate solution for R
L
> 0Ω:
E
IL
R
VV
IR
V
AS
L
L
bb OUT CL
LL
OUT CL
=+ +
*
*
*( | )*ln(
*
||
)
()|
()
2
1