A 98% efficient bidirectional buck-boost controller for 12V-12V redundant battery systems in autonomous vehicles

Analog Devices has announced the Power by Linear, a 98% efficient bidirectional buck-boost switching regulator controller that operates between two batteries with the same voltage, designed for redundancy in self-driving cars.

The LT8708/-1 operates from an input voltage that can be above, below or equal to the output voltage, making it well suited for two each 12V, 24V or 48V batteries commonly found in electric and hybrid vehicles. It operates between two batteries and prevents system shut-down should one of the batteries fail. The LT8708/-1 can also be used in 48V/12V and 48V/24V dual battery systems.

Another application is for an input voltage to power a load, where this same input voltage is used to power a LT8708/-1 circuit that charges a battery or bank of supercapacitors. When the input voltage goes away, the load maintains power without disruption from the battery or supercaps by way of the LT8708’s bidirectional capability.

Forward and reverse current can be monitored and limited for the input and output sides of the converter. All four current limits (forward input, reverse input, forward output and reverse output) can be set independently using four resistors.In combination with the DIR (direction) pin, the chip can be configured to process power from VINto VOUTor from VOUTto VIN, ideal for automotive, solar, telecom and battery-powered systems.

The LT8708 is available in a 5mm x 8mm QFN-40 package. Three temperature grades are available, with operation from –40 to 125°C for the extended and industrial grades and a temp automotive range of –40°C to 150°C.

Bethan Grylls