Dual synchronous controllers claim lowest quiescent current

Renesas Electronics Corp. has released a pair of 42-V dual synchronous controllers, claiming the industry’s lowest quiescent current of 6 µA. The dual-output controllers, the ISL78264 and ISL78263, with integrated 2-A source/3-A sink MOSFET drivers provide primary power stage solutions for the Renesas R-Car H3 and R-Car M3 SoCs.

“The controllers’ always-on operation and industry’s lowest quiescent current gives power system designers the extra margin they need to stay within their 100 µA power budget, and can even manage tight budgets down to 50 µA,” said Niall Lyne, vice president, Automotive Analog Power & Video Business Division at Renesas, in a statement.

The ISL78264 dual sync buck controller manages the intermediate first stage DC/DC conversion, stepping down the 12-V battery system to 5 V and 3.3 V to power the vehicle’s electronic control unit (ECU), in-vehicle infotainment (IVI), and digital cockpit systems with 50 W-200 W power levels.

Key ISL78264 specs include:

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

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

Key ISL78263 specs:

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

Both controllers simplify power supply design by integrating FET drivers that can deliver 96 percent peak efficiency and >10 A output current, said Renesas. 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.

Having built-in EMI mitigation, with a switching frequency up to 2.2 MHz, said Renesas, also reduces the cost and size of EMI filtering/shielding.

The devices also provide 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°C to 125°C.

The dual synchronous boost and buck controllers are available now in 5 x 5 mm, 32-lead wettable flank QFN packages.