Two dual-output synchronous controllers for automotive

The ISL78264 dual sync buck controller manages the intermediate first stage DC/DC conversion, stepping down the 12V battery system to five and 3.3V to power the vehicle’s electronic control unit (ECU), in-vehicle infotainment (IVI) and digital cockpit systems with 50 to 200W power levels.

The ISL78263 dual sync boost and buck controller provides DC/DC conversion to support power levels of 25W-100W, while providing a pre-boost if the battery voltage (VBAT) dips to as low as 2.1V during a cranking transient or a start/stop event.

“The ISL78264 and ISL78263 provide the ideal primary stage power regulation solutions for Renesas’ R-Car H3 and R-Car M3 SoCs, which are introducing the automotive industry to new electronic architectures that improve vehicle performance, efficiency, safety, and reliability,” said Niall Lyne, Vice President, Automotive Analog Power & Video Business Division at Renesas. “The controllers’ always-on operation and industry’s lowest quiescent current gives power system designers the extra margin they need to stay within their 100µA power budget, and can even manage tight budgets down to 50µA. The ISL78264 and ISL78263 integrate strong MOSFET drivers that deliver higher efficiency and power compared to other automotive buck or boost VBAT controller solutions.”

The ISL78264 dual sync buck controller and the ISL78263 dual sync boost and buck controller offer energy conserving low quiescent current (Iq) of 6µA (typ) over a single buck channel. Both controllers simplify power supply design by integrating FET drivers that can deliver industry leading 96% peak efficiency and >10A output current.

They also integrate feedback resistors and an external supply blocking diode for applications requiring cranking support, and programmable spread spectrum for addressing EMI interference challenges. For example, tolerating a VBAT load dump reduces the additional cost and size of surge protection, while supporting cranking transients lowers the amount of required input capacitance. Having built-in EMI mitigation, with a switching frequency up to 2.2MHz, also reduces the cost and size of EMI filtering/shielding.

The ISL78264 and ISL78263 also include extensive protection for overvoltage (OV), undervoltage (UV), overcurrent, overtemperature, and a bootstrap supply undervoltage detection and refresh circuit to protect the high side MOSFET. Both controllers are AEC-Q100 Grade-1 qualified for ambient operation of -40 to +125°C.

ISL78264

• Input voltage operation of 3.75V to 42V
• Buck1 Vout is fixed at 3.3V/5V or adjustable from 0.8V to 5V
• Buck2 Vout is adjustable from 0.8V to 32V
• Low Iq of 6µA (typ) over a single buck channel
• 25ns on-times for low duty-cycle operation, and 180° phase shift between channels
• Supports start-stop cranking transients down to 5.5V @ 2MHz without requiring pre-boost

ISL78263

• Input voltage operation from 2.1V to 42V
• Fixed buck at 3.3V/5V adjustable
• Keeps buck output in regulation through cold-crank transients down to 2.1V
• Boost frequency at 1x or 0.2x the buck frequency
• Drop-out mode (buck) for high duty-cycle operation
• 25ns on-times for low duty-cycle operation

Mass production quantities of the ISL78264 dual synchronous buck controller and ISL78263 dual synchronous boost and buck controller are available now in 5x5mm, 32-lead wettable flank QFN packages.