Active FET-based-rectifier controller with reverse protection, automotive rated

November 14, 2017 //By Graham Prophet
Following its acquisition of Linear Technology, Analog Devices has created the branding “Power by Linear” for power-related devices from that product line. Newly-added is the LT8672, an active rectifier controller with reverse input protection to –40V.

The device’s 3V to 42V input voltage capability is suitable for automotive applications which must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3.0V and load dump transients up to 40V. The LT8672 drives an external N-channel MOSFET, offering a 20 mV drop, reducing power dissipation by 90% compared to a Schottky diode, and eliminating requirements for a heat sink. Its ultrafast transient response enables it to meet stringent automotive applications requiring AC input ripple rectification up to 100 kHz. A 20 µA quiescent current while operating, and 3.5 µA in shutdown, are suitable for always-on systems. The combination of the MSOP-10 package and external MOSFET aids a compact footprint.

 

The LT8672 offers the combination of 3V minimum input capability and a 20 mV drop, enabling it to ease the minimum input voltage requirement during cold-crank and stop-start, providing simpler and more efficient circuits. If the input power source fails or is shorted, a very fast turn-off minimizes reverse current transients. Also, a power-good pin signals when the external MOSFET is ready to take load current.

 

The LT8672EMS is packaged in an MSOP-10 package. An industrial temperature version, the LT8672IMS, is tested and guaranteed to operate from a –40°C to 125°C operating junction temperature. The LT8672HMS version is tested and guaranteed to operate from a –40°C to 150°C operating junction temperature. In MSOP-10, pricing starts at $2.25 (1000).

 

Analog Devices/Linear Technology; www.linear.com/product/LT8672

 

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