December 11, 2012 – Linear Technology Korea (CEO Hong Sa-gwak) announced the launch of the LTC4417, a PowerPath™ controller that prioritizes triple power sources for 2.5V ~ 36V systems. This controller selects the highest-priority valid power source from three inputs and supplies power to the load. Priority is defined by pin assignment, and the power is considered valid after 256ms with low-voltage and overvoltage thresholds set to 1.5% accuracy, placing the voltage within the window. The LTC4417 significantly simplifies design while drawing power from multiple voltage sources at different potentials commonly used in handheld and commercial electronic products. In these systems, the priority function serves as a superior solution compared to simple diode OR when the desired power source is not the highest voltage. The LTC4417 controller also protects the load up to −42V on reverse input.

PowerPath switching is implemented with external back-to-back P-channel MOSFETs protected with an integrated 6V gate clamp. Carefully designed high-speed switch control prevents reverse conduction current and cross conduction current while preventing output voltage droop. Low 28µA operating current, less than 1µA from lower standby power, and shutdown mode make this an ideal controller for battery backup systems. The LTC4417's wide operating range accommodates various power sources including wall adapters, USB, Firewire, supercapacitors, as well as batteries such as lead-acid, lithium-ion, and stacked NiCd. Built-in cascading support capability extends the LTC4417 priority method to three or more power sources. To minimize inrush current, initial connection starts soft. Open-drain output indicates power sources within the valid voltage window. Low-voltage and overvoltage hysteresis can be adjusted with a single resistor.

Qualified to full commercial, industrial and automotive temperature ranges, the LTC4417 is available in 24-pin QFN (4mm x 4mm) and 24-pin narrow SSOP packages. At 1,000-unit quantities, the unit price is set at $3.05 and devices are available in production quantities. Evaluation circuit boards are available through Linear Technology sales offices or online. For more information, refer to www.linear.com/powerpath_controllers.

Photo Caption: PowerPath™ Controller selecting highest priority valid input and protecting against reverse input,

Product Features: LTC4417
Connects highest-priority valid power source to output
Valid power proven with 256ms, 1.5% precision overvoltage & low-voltage confirmation
Wide operating voltage range: 2.5V ~ 36V
−42V protection against reverse battery
Prevents reverse conduction & cross conduction
Fast switchover minimizing output voltage droop
Low 28μA operating current
Less than 1μA current from power sources below VOUT
Adjustable overvoltage & low-voltage hysteresis
Cascadable for additional input power sources
Supplied in 24-pin SSOP & QFN packages