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FUNCTIONAL DESCRIPTION
The device has a
indicates open load conditions in off state as well
as in on state, output shorted to V
CC
and
overtemperature. The truth table shows input,
diagnostic and
output
operation and in fault conditions.
signals
are
processed
open load diagnostic output has a 5 ms filtering.
The filter gives a continuous signal for the fault
condition after an initial delay of about 5 ms. This
means
that
a
disconnection during
operation, with a duration of less than 5 ms does
not
affect the
status output.
re-connection of less than 5 ms during a
disconnection duration does not affect the status
output. No delay occur for the status to go low in
case of overtemperature conditions. From the
falling edge of the input signal the status output
initially low in fault condition (over temperature or
open load) will go back with a delay (t
povl
)in case
of overtemperature condition and a delay (t
pol
) in
case of open load. These feature fully comply
with
International
Standard
requirement for automotiveHighSide Driver.
To protect the device
against short circuit and
over current conditions, the thermal protection
turns the integrated Power MOS off
minimum
junction
temperature
When the temperature returns to 125
switch is automatically turned on again.In short
circuit the protection reacts
delay, the sensor being located in the region of
the die where the heat is generated. Driving
inductive loads,
an
device ensures the fast demagnetizationwith a
diagnostic output which
voltage level in normal
The output
by internal logic. The
normal
Equally, any
Office
(I.S.O.)
at
a
of 140
o
C.
o
C the
with
virtually no
internal function of the
typicalvoltage (V
demag
) of -18V.
This function allows to greatly reduce the power
dissipationaccording to the formula:
P
dem
= 0.5
L
load
(I
load
)
2
[(V
CC
+V
demag
)/V
demag
]
f
where f = switchingfrequency and
V
demag
= demagnetizationvoltage
Based on this formula it is possible to know
the value of inductance and/or current to avoid
a thermal shut-down. The maximum inductance
which causes the chip temperature to reach the
shut down temperature in a specific thermal
environment, is infact a function of the load
current for a fixed V
CC
, V
demag
and f.
PROTECTING THE DEVICE AGAIST LOAD
DUMP - TEST PULSE5
The device is able to withstand the test pulse
No. 5 at level II (V
s
= 46.5V) according to the
ISO T/R 7637/1
without
component. This means that all functions of the
device
are
performed
exposure to disturbanceat level II. The VN06SP
is able to withstand the test pulse No.5 at level
III adding an
external resistor of
between GND pin and ground plus a filter
capacitor of 1000
μ
F between V
CC
pin and
ground (if R
LOAD
≤
20
).
any
external
as
designed
after
150 ohm
PROTECTING
REVERSE
The simplest way to protect the device against a
continuous reverse battery voltage (-26V) is to
insert a Schottky diode between GND pin and
ground, as shown in the typical application circuit
(fig.3).
The consequences of the voltage drop across
this diodeare as follows:
If the input is pulled to power GND, a negative
voltage of -V
f
is seen by the device. (Vil, Vih
thresholds and Vstat are increased by Vf with
respect to power GND).
The undervoltageshutdown level is increa-
by Vf.
If there is no need for the control unit to handle
external analog signals referred to the power
GND, the best approach is to connect the
reference potentialof the control unit to node [6]
(see application circuit in fig. 4), which becomes
the common signal GND for the whole control
board avoiding shift of V
ih
, V
il
and V
stat
. This
solutionallows the use of a standard diode.
THE
DEVICE
AGAINST
BATTERY
sed
Switching Time Waveforms
VN03SP
5/9