Low-Power, High-Voltage Detection/Protection Circuits Operate Up to 72V for High-Voltage Transient Systems
| Note to Editor: The MAX6495-MAX6499 are overvoltage protection circuits that operate from 5.5V to 72V. Operating as a switch controller, these circuits either shut off or regulate the output voltage during an overvoltage condition. These high-voltage devices allow use of lower input regulators in high-voltage transient systems such as those found in industrial and automotive applications. |
SUNNYVALE, CA-August 29, 2005-Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX6495-MAX6499 overvoltage protection circuits that operate as a switch controller to either disconnect or limit the output voltage to a load during an overvoltage condition. The circuits turn off an external n-channel MOSFET with an internal 100mA pulldown current when the monitored voltage exceeds its overvoltage threshold. These low-power devices consume only 20 microamps of quiescent current and operate from 5.5V to 72V, making them suitable for automotive, industrial, and server applications.
The MAX6497 features a latch-off mode that disables the MOSFET until the power or shutdown input is cycled. The MAX6498 features an autoretry mode that attempts to turn on the MOSFET when the voltage falls to 130mV. Three of the devices (MAX6495/MAX6496/MAX6499) can also be configured as a voltage limiter that provides a regulated output to allow for continuous operation. An internal charge pump on all circuits provides a 10V gate-to-source enhancement to minimize drain-to-source resistance during normal operation. Other features include a POK indicator (MAX6497/MAX6498) and the control logic for driving a p-channel MOSFET to provide reverse battery protection. All devices offer a shutdown input. These protection circuits are offered in a small 3mm x 3mm TDFN package and are fully specified from -40 degrees Celsius to 125 degrees Celsius. Prices for these devices start at $1.23 (1000-up, FOB USA).
|
