Intersil – 8A step-down regulator achieves up to 97% efficiency


The ISL8018 from Intersil is a synchronous step-down DC-DC converter IC which can supply up to 8A continuous output current from a 2.7V to 5.5V input supply.

The output voltage of the ISL8018 is adjustable in a range from 0.6V up to the value of the input voltage. It uses a current-control architecture to provide a fast response to transient events and excellent loop stability.

The ISL8018 integrates a pair of P- and N-channel MOSFETs, helping to minimise the external component count. With a dropout of less than 250mV at an output current of 8A, the regulator achieves very high efficiency of up to 97%. In addition, adjustable frequency and synchronisation allow the ISL8018 to be used in applications requiring low noise.

The ISL8018 can be configured for discontinuous or forced continuous operation at light loads. Forced continuous operation reduces noise and RF interference, while discontinuous mode provides high efficiency by reducing switching losses at light loads.

The ISL8018 is supplied in a 3mm x 4mm QFN package with exposed-pad lead frames for excellent thermal performance.


  • ±10% output-voltage margining
  • Adjustable current limit
  • Start-up with pre-biased output
  • Internal soft-start
  • Frequency adjustable between 500kHz and 4MHz
  • Short-circuit protection
  • Over-temperature protection


  • Point-of-load modules
  • Power supplies for microcontrollers, microprocessors, FPGAs and DSPs
  • DC-DC converter modules for routers and switchers
  • Portable instruments
  • Test and measurement systems
  • Devices powered by a lithium-ion battery


The ISL8018EVAL3Z evaluation board is intended for use in point-of-load applications sourcing between 2.7V and 5.5V. The complete converter circuit occupies an area of 439mm2.

Orderable Part Number: ISL8018EVAL3Z