June 15, 2012 – Linear Technology Korea (CEO Hong Sa-kwak) announced the development of a 0V to 18V dual ideal diode controller (Product Name: LTC4353). This product is used in place of two high-power Schottky diodes to enable low-loss ORing of multiple power supplies with minimal disturbance to the supply voltage. The LTC4353 regulates the forward voltage drop of an external N-channel MOSFET to allow for smooth current switching between supplies in diode OR applications. In low-voltage systems, slow handoff between controllers results in voltage drops during supply switching.

With a fast on-time of less than 1µs, the LTC4353 enables seamless switching from one path to another without oscillation. In the event of an input supply failure or short circuit, the fast turn-off minimizes reverse current. In addition to redundant power supply ORing, the LTC4353 can also serve as an excellent diode replacement solution for supply hold-up applications that provide stable power to the load during momentary voltage collapse.

The LTC4353 provides individual enable inputs, allowing priority to be given to the main supply when the supply voltages are at each other's MOSFET body diode drops. With both enable pins low, the LTC4353 consumes only 75µA of current per supply. The individual status output indicates whether the MOSFET is on or off. This controller operates with a supply of 2.9V to 18V and can control voltages as low as 0V by applying an external supply.

The LTC4353 is currently the only dual low-voltage ideal diode controller in the industry, and it is significantly superior to competing solutions in terms of space savings. The LTC4353 is available in 16-pin MSOP and 4mm x 3mm DFN packages and operates over general commercial and industrial temperature ranges. The product is priced at $3.45 per unit in 1,000-piece orders. For detailed product information, please refer to www.linear.com/product/LTC4353 .

Image caption: Fast turn-on dual ideal diode controller

Product Features: LTC4353
• A low-loss solution to replace Schottky power diodes in multi-power supply and supply hold-up applications
• External N-channel control for high current function
• 0V ~ 18V Supply ORing or Hold Up
• 1µs turn-on and turn-off time
• Enable Input
• MOSFET On-state Output
• 16-pin MSOP & DFN (4mm x 3mm) package