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VNS3NV04D
PROTECTION FEATURES
During normal operation, the INPUT pin is
electrically connected to the gate of the internal
power MOSFET through a low impedance path.
The device then behaves like a standard power
MOSFET and can be used as a switch from DC to
50KHz. The only difference from the user’s
standpoint is that a small DC current I
ISS
(typ.
100µA) flows into the INPUT pin in order to supply
the internal circuitry.
The device integrates:
- OVERVOLTAGE CLAMP PROTECTION:
internally set at 45V, along with the rugged
avalanche characteristics of the Power MOSFET
stage give this device unrivalled ruggedness and
energy handling capability. This feature is mainly
important when driving inductive loads.
- LINEAR CURRENT LIMITER CIRCUIT: limits
the drain current I
D
to I
lim
whatever the INPUT pin
voltage. When the current limiter is active, the
device operates in the linear region, so power
dissipation may exceed the capability of the
heatsink. Both case and junction temperatures
increase, and if this phase lasts long enough,
junction temperature may reach the
overtemperature threshold T
jsh
.
- OVERTEMPERATURE AND SHORT CIRCUIT
PROTECTION: these are based on sensing the
chip temperature and are not dependent on the
input voltage. The location of the sensing element
on the chip in the power stage area ensures fast,
accurate detection of the junction temperature.
Overtemperature cutout occurs in the range 150 to
190 °C, a typical value being 170 °C. The device is
automatically restarted when the chip temperature
falls of about 15°C below shut-down temperature.
- STATUS FEEDBACK: in the case of an
overtemperature fault condition (T
j
> T
jsh
), the
device tries to sink a diagnostic current I
gf
through
the INPUT pin in order to indicate fault condition. If
driven from a low impedance source, this current
may be used in order to warn the control circuit of
a device shutdown. If the drive impedance is high
enough so that the INPUT pin driver is not able to
supply the current I
gf
, the INPUT pin will fall to 0V.
This will not however affect the device
operation: no requirement is put on the current
capability of the INPUT pin driver except to be
able to supply the normal operation drive
current I
ISS
.
Additional features of this device are ESD
protection according to the Human Body model
and the ability to be driven from a TTL Logic
circuit.
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Obsolete Product(s) - Obsolete Product(s)
