Active FET-based-rectifier controller with reverse protection, automotive rated
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
next page; feature summary;
LT8672
Reverse input protection to –40V
Wide operating voltage range: 3V to 42V
Low 20 µA quiescent current in operation
Improved performance compared to a Schottky diode:
– Reduce power dissipation by >90%
– Reduce drop to 20 mV
Ultrafast transient response
– Rectifies 6 VP-P up to 50 kHz
– Rectifies 2 VP-P up to 100 kHz
Low 3.5 µA shutdown current
Accurate 1.21V enable pin threshold
Available in small 10-lead MSOP