The ISL78263 offers synchronous boost and buck controllers. The boost controller operates either as an independent channel or as a pre-boost function that supplies the buck controller. The low-IQ buck controller uses only 6µA quiescent current, allowing it to support low-power, always-on operation. Both controllers support wide duty-cycles for switching frequencies from 200kHz to 2.2MHz. Both devices can be synchronized to an external clock and offer programmable spread spectrum clocking to mitigate EMI.

In pre-boost buck mode, the boost of the ISL78263 can be set to activate during falling VIN transients and continues to operate with an input voltage down to 2.1V. This allows the buck output to maintain regulation, even as the VIN voltage falls below its output. To support the increase in input current that occurs when VIN falls, the ISL78263 integrates robust MOSFET drivers to allow the use of multiple FETs in parallel.

ISL78263 is qualified to AEC-Q100 Grade 1 and is specified to operate across an ambient temperature range of -40°C to 125°C. The device is available in a 5mmx5mm, 32 Ld WFQFN (Wettable Flank) package. The features of the ISL78263 make it ideally suited as a front-end regulator for automotive systems that must maintain always-on operation and support severe cold-cranking transients.


  • VIN operating range: 2.1 to 42V
  • Low quiescent current: 6µA typical, buck channel
  • Switching frequency: 200kHz to 2.2MHz
  • Boost frequency at 1x or 0.2x the buck frequency
  • Dropout mode (buck) for high duty-cycle operation
  • 25ns on-times for low duty-cycle operation
  • External synchronization
  • Programmable spread spectrum clocking
  • 2A Sourcing / 3A sinking MOSFET drivers
  • Boot UV and programmable boot refresh time
  • Extensive protection mechanisms for OV/UV/OC/OT




  • Automotive battery supplied application
  • In cabin systems
  • ADAS: Advanced Driver Assist Systems
  • Start-stop protected systems (such as head unit, cluster, e-Mirror)


Type Title Date
Datasheet PDF 1.82 MB
Brochure PDF 5.49 MB 日本語
Product Advisory PDF 414 KB
Product Change Notice PDF 211 KB
Manual - Development Tools PDF 1.36 MB
5 items

Design & Development

Boards & Kits

Boards & Kits


ISL78263/4 Dual 40V Low IQ Controllers With Spread Spectrum Clocking

Renesas introduces the ISL78263 and ISL78264 dual output synchronous controllers with low IQ for automotive always-on systems.