The LTC4366 high voltage surge stopper from Linear Technology is an overvoltage protection controller for electronic systems that protects loads from high voltage transients. Operating from 9V to greater than 500V, the LTC4366 floating surge stopper utilizes an adjustable floating topology to enable very high voltage operation independent of the voltage rating of the LTC4366’s internal circuitry.
Two internal shunt regulators coupled with the external voltage-dropping resistors generate the LTC4366’s internal supply rails. The maximum operating voltage is set by the breakdown of the external resistors and MOSFETS. The LTC4366 is the first product of its kind to protect, for example, a 12V circuit from a 500V transient without the need for additional protection components.
The LTC4366 monitors the voltage at its output and reacts quickly to input supply overvoltage by controlling the gate of an N-channel MOSFET. This device regulates the output to a user-defined voltage during an overvoltage transient allowing the load to remain operational while the overvoltage is dropped across a MOSFET.
Placing a resistor in the return line isolates the LTC4366 and allows it to float up with the supply; therefore, the upper limit on the output voltage depends only on the availability of high valued resistors and MOSFET ratings. An adjustable fault timer ensures safe shutdown if the fault persists.
This adjustable overvoltage timer prevents MOSFET damage during the surge while an additional 9 second timer provides for MOSFET cool down. A shutdown pin reduces the quiescent current to less than 14µA during shutdown. After a fault the LTC4366-1 latches off while the LTC4366-2 will auto-retry.
This high voltage surge stopper is ideal for harsh industrial, automotive and avionic applications where systems must continue operating reliably through severe overvoltage events. High voltage applications include protecting from motor transients, coupled overvoltage, incorrect input supplies or power supply failures.
While traditional protection circuitry relies on bulky inductors, capacitors, fuses and transient voltage suppressors to clamp the transient, the LTC4366 protects by series regulating the transient. It is packaged in a tiny 8-lead TSOT-23 and 3mm x 2mm DFN packages. During operation, the entire circuit consumes only a few milliamperes, and the device may be shut down to less than 20µA.
The LTC4366 is available in two options; the LTC4366-1 latches off after a fault, while the LTC4366-2 will retry after a 9-second cool down period. Devices are specified over the full commercial, industrial and automotive temperature ranges. Pricing begins at $2.65 each for 1,000-piece quantities and the device is available in production quantities.
For more information, visit www.linear.com/product/LTC4366.
Summary of Features of the LTC4366:
- Rugged Floating Topology with User Adjustable Max Output
- Wide Operating Input and Output Voltage Range: 9V to >500V
- Adjustable Output Clamp Voltage
- External N-Channel MOSFET Sets Max VIN
- Adjustable Protection Timer
- Internal 9-Second Cooldown Timer
- Shutdown Current < 20µA
- 8-Lead TSOT & 3mm x 2mm DFN Package
About Linear Technology
Linear Technology Corporation, a manufacturer of high performance linear integrated circuits, was founded in 1981, became a public company in 1986 and joined the S&P 500 index of major public companies in 2000. Linear Technology products include high performance amplifiers, comparators, voltage references, monolithic filters, linear regulators, DC-DC converters, battery chargers, data converters, communications interface circuits, RF signal conditioning circuits, µModule products, and many other analog functions. Applications for Linear Technology’s high performance circuits include telecommunications, cellular telephones, networking products such as optical switches, notebook and desktop computers, computer peripherals, video/multimedia, industrial instrumentation, security monitoring devices, high-end consumer products such as digital cameras and MP3 players, complex medical devices, automotive electronics, factory automation, process control, and military and space systems.
Linear Technology (UK) Limited
Tel: +44 (0)1628 477066
E-mail: uksales@linear.com
Web site: www.linear.com
Website for product information: http://www.linear.com/product/LTC4366
