Prioritize Power Sources in Any Order, Regardless of Relative
Voltage: No ВµP Required
Sam Tran Does your application have multiple input power sources? Are one or more secondary
source voltages equal to or higher than the main source? How do you ensure the
main source powers the output when a higher voltage, secondary source is present?
How do you prevent sources from cross conducting, or backfeeding during input
source switchover? Do you need to prevent current sharing between similar voltage
sources? Are you worried about users plugging in sources backwards or plugging in
overvoltage sources to the system? The LTC4417 prioritized PowerPathв„ў controller,
with its wide 2.5V to 36V operating voltage range, solves all these issues by controlling
the connection of the input sources based on user-defined priority and validity while
protecting the system from overvoltage and reverse voltage insertions up to В±42V.
PRIORITIZING THREE
INPUT SOURCES FigureВ 1 shows a triple-input prioritizer.
Here, the 12V wall adapter is given top
priority, the 14.8V Li-ion battery stack is
prioritized second, and 12V sealed lead
acid (SLA) battery has the lowest priority.
Priority is simply set by connecting the
sources to the LTC4417 in pin order: V1 is
the highest priority; V3 the lowest priority.
The LTC4417 connects a higher priority input source to the output as long
as the input source voltage remains …