June 1, 2012 – Linear Technology Korea (CEO Hong Sa-gwak) announced the launch of a high-voltage ideal diode controller (product name: LTC4359). This product provides a simple, low-loss solution that can replace Schottky diodes with key features for automotive, aerospace, and photovoltaic applications. The LTC4359 operates within a supply voltage range of 4V to 80V and can withstand input voltages from -40V to 100V without device damage. The LTC4359 has a low operating current of 150µA and enables low-current shutdown mode operation that consumes only 13µA through a shutdown control input.
Additionally, the LTC4359 is designed to operate within an ambient temperature range of -40°C to 125°C. Based on these characteristics, the LTC4359 can protect loads in demanding automotive environments such as load dump, cold crank, dual-battery jump-start, and reverse battery connection. When used together with the LT4363 high-voltage surge stopper, the LTC4359 provides robust front-end protection from overvoltage, overcurrent, and reverse battery conditions. The device's low operating current characteristic is also advantageous for photovoltaic systems, as the LTC4359 provides a low-loss path that isolates solar panels from the load.
The LTC4359 controls an external N-channel MOSFET to function as a low forward voltage drop diode. This provides a lower loss path compared to Schottky diodes and delivers a more efficient solution in high-power applications, while eliminating the need for heat sinks to save valuable board space. Additionally, back-to-back MOSFET control is possible to prevent current from flowing from input to output during shutdown. The LTC4359 controls the forward voltage drop across the MOSFET to ensure current flows smoothly even under light loads without oscillation. With a fast turn-off time of less than 1µs when power fails or a short occurs, reverse current transient overvoltage can be minimized.
The LTC4359 single ideal diode controller can also be used in applications where multiple power supplies are connected in parallel to provide redundancy. In N+1 redundant systems, an additional supply is provided so that the system remains safely protected even if one of the supplies fails. ORing supplies together allows disconnection from the power bus in case of input failure or short circuit. Additionally, the LTC4359 can be used with reservoir capacitance to delay the supply for a certain period after power loss occurs. This allows the system to continue operating without resetting or rebooting due to brief input power interruptions.
The LTC4359 is part of the ideal diode controller product family, with related products including the single high-voltage LTC4357 ideal diode controller, LTC4355 positive diode-OR, LTC4354 negative diode-OR controller, and 0V to 18V LTC4352 single ideal diode controller. This ideal diode controller portfolio is complemented by Linear's comprehensive surge stopper and Hot Swap™ controller products, such as the high-voltage LTC4260 hot swap controller with an integrated ADC for extensive system monitoring.
Operating in commercial, industrial, and automotive temperature ranges, the LTC4359 is available in 2mm x 3mm 6-pin DFN and 8-pin MSOP packages. These products are available for immediate purchase, starting at $2.10 per unit based on quantities of 1,000. Demo boards and free samples can be purchased online or through Linear's regional sales offices. For detailed product information, visit www.linear.com/idealdiodes.

Photo Caption: High-voltage ideal diode controller capable of withstanding reverse voltage

Product Features: LTC4359

Power Schottky diode replacement
Wide operating voltage range: 4V to 80V
Reverse input protection down to -40V
Low 13µA shutdown current
Low 150µA operating current
Smooth switchover without oscillation
-40°C to 125°C operation
8-pin MSOP & 2mm x 3mm 6-pin DFN package