Sunnyvale, Calif. These overvoltage protectors from Maxim Integrated Products Inc. were made for systems with high-transient voltages like automotive and industrial applications.
The overvoltage protector trio operates from 5.75 V to 72 V. The parts can be configured either as a switch controller that turns off an external n-channel switch during an overvoltage condition, or as a voltage limiter that regulates the output to allow continuous operation.
An adjustable threshold allows two external resistors to set the overvoltage threshold
level. An internal charge pump ensures that the n-channel switch is fully
enhanced during normal operating mode. In the switch-controller mode, the
n-channel MOSFET is quickly shut off as the MOSFET's gate is quickly
pulled down through an internal current source. In the voltage-limiting
mode, the MOSFET is turned on and off to maintain a regulated voltage at
the output. These devices provide the necessary protection and reduce
system cost by allowing use of lower input-voltage DC/DC regulators, according to the company.
The MAX6397 has an independent always-on linear regulator that can deliver
up to 100 mA output current with four fixed-output options of 5 V, 3.3 V,
2.5 V, and 1.8 V. This device also features a power-good indicator.
The MAX6399 offers both an undervoltage and overvoltage threshold with a
power-good indicator. An overvoltage latch mode keeps the n-channel MOSFET
off until the power is recycled or the shutdown input is toggled. Other
MAX6399 features include a shutdown input for manually shutting off the
n-channel switch and thermal shutdown protection.
All three devices are offered in a 3mm x 3mm TDFN package and are
fully specified from the -40°C to +125°C automotive temperature range. Evaluation kits are also available.
Pricing starts at $1.23 (1000-up, FOB USA).Click here for the MAX6397/MAX6398 preliminary data sheets.
Maxim , 1-800-998-8800, www.Maxim-ic.com.