Automotive grade non-synchronous boost controller has wide input range

August 22, 2011 // By Christoph Hammerschmidt
ON Semiconductor has introduced a new adjustable output non-synchronous boost controller for automotive systems. The NCV8871 is a wide input voltage device, with a range of 3.2 V to 44 V, which can be used to drive an external N−channel MOSFET.

The device incorporates an internal regulator that supplies charge to the gate driver. It has a 3.0 microampere (µA) quiescent current when in sleep mode, allowing power consumption to be minimized. It features a synchronizable switching frequency, with two available versions that can be set at 170 kHz typical, or 1 MHz typical. Peak current mode control with internal slope compensation ensures device stability over the wide automotive battery range. This also ensures the device is protected during a current fault condition by turning off the power switch for the remainder of the cycle if the current limit is exceeded. Further protection is provided by a thermal shutdown mechanism (with a 170 ⁰C threshold) and a 3.1 V undervoltage lockout.

The NCV8871 is highly programmable with various other frequency options available upon request. Additional options include different slope compensation values, current limit set points and different gate drive voltages for interfacing with various MOSFETs. The device also supports multiple topology configurations, including boost, flyback, SEPIC, and multi-phase. Output power ranges from a few watts (W) up to 200 W in a boost topology.

“The NCV8871 operates down to 3.2 V, whereas alternative controller solutions on the market typically only go down to 4 V,” said Jim Alvernaz, director of the automotive product division at ON Semiconductor. “This makes the device highly optimized for engine start/stop applications. Its high level of integration brings other benefits too. Previously, the only option for engineers was to utilize more complex devices, which had higher pin counts and called for a larger number of external components. The NCV8871 simplifies the design process, reduces the bill of materials, and shortens the design time.”

The NCV8871 has an operating junction temperature of −40 ⁰C to 150 ⁰C. The device is offered in a Pb-free, RoHS compliant SOIC-8 package, and is priced at $0.83 per unit in quantities of 2,500 units.

For more information, visit http://www.onsemi.com.