The MAX6495–MAX6499 is a family of small, low-current,
overvoltage-protection circuits for high-voltage
transient systems such as those found in automotive
and industrial applications. These devices monitor the
input voltage and control an external n-channel MOSFET
switch to isolate the load at the output during an input
overvoltage condition. The MAX6495–MAX6499 operate
over a wide supply voltage range from +5.5V to +72V.
The gate of the n-channel MOSFET is driven high while
the monitored input is below the user-adjustable overvoltage
threshold. An integrated charge-pump circuit
provides a 10V gate-to-source voltage to fully enhance
the n-channel MOSFET. When the input voltage
exceeds the user-adjusted overvoltage threshold, the
gate of the MOSFET is quickly pulled low, disconnecting
the load from the input. In some applications, disconnecting
the output from the load is not desirable. In
these cases, the protection circuit can be configured to
act as a voltage limiter where the GATE output sawtooths
to limit the voltage to the load (MAX6495/MAX6496/MAX6499).
The MAX6496 supports lower input voltages and
reduces power loss by replacing the external reverse
battery diode with an external series p-channel MOSFET.
The MAX6496 generates the proper bias voltage to
ensure that the p-channel MOSFET is on during normal
operations. The gate-to-source voltage is clamped during
load-dump conditions, and the p-channel MOSFET
is off during reverse-battery conditions.
The MAX6497/MAX6498 feature an open-drain, undedicated
comparator that notifies the system if the output
falls below the programmed threshold. The MAX6497
keeps the MOSFET switch latched off until either the
input power or the active-low SHDN pin is cycled. The MAX6498
will autoretry when VOVSET falls below 130mV.
These devices are available in small, thermally
enhanced, 6-pin and 8-pin TDFN packages and are
fully specified from -40°C to +125°C.
Key Features
Applications/Uses
Wide Supply Voltage Range: +5.5V to +72V
Overvoltage-Protection Switch Controller Allows User to Size External n-Channel MOSFETs
Fast Gate Shutoff During Overvoltage with 100mA Sink Capability
Notes: *This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
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and delivery, please see the price and availability page
or contact an authorized distributor.