Intersil – ISL8003x family : High Efficiency DC/DC Converters Step Down 5V Rails to Point-of-Load (POL)

The new highly integrated synchronous buck regulators that step down 5V rails to POL inputs are as low as 0.6V for FPGAs, DSPs and microprocessors.

The feature-rich ISL8018 delivers up to 8A of continuous output current from a 2.7V to 5.5V input supply, while offering up to 97% efficiency and higher integration than competitive devices. The 2 x 2mm ISL8003x family of devices delivers up to 3A of continuous output current from a 2.7V to 5.5V input supply and offers up to 95% peak efficiency for delivering general POL conversions in telecom, cloud computing, industrial, instrumentation and medical equipment.

The ISL8018 provides an innovative SYNCIN and SYNCOUT feature that connects and synchronizes multiple regulators at the same switching frequency in a master/slave configuration using a phase shifting time delay. This prevents ON time overlapping and reduces RMS current, ripple and input capacitance requirements to improve EMI and efficiency. With the ISL8018’s VSET feature, the voltage output margining can be set at ± 10% to compensate for output voltage IR drop. The ISET feature provides programmable output current limits to support 8A, 5A and 3A applications. This allows customers to leverage one design with smaller inductors for reduced costs and board area. In addition, the ISL8018’s programmable switching frequency from 500kHz up to 4MHz enables the use of smaller passive components for faster transient response and further board space savings.


The ISL80030, ISL80030A, ISL80031, and ISL80031A are pin-compatible and integrate very low RDS(ON) high side PMOS and low side NMOS MOSFETs, which reduces external component count and power losses. With lower die temperatures, these buck regulators allow the system to operate without cooling fans or heat sinks and still deliver a continuous 3A to the load, significantly increasing reliability. They also offer internal compensation, which eliminates additional external components to reduce design complexity. The complete converter occupies less than 64mm2 of board space. And the ISL80031 and ISL80031A offer a light load mode to improve efficiency over all load currents when the system switches to a low power state.

These synchronous buck regulators can be combined with the ISL85033 dual 3A output synchronous buck regulator in POL applications, and the ISL85003 4.5V to 18V, 3A synchronous buck regulator for a two-stage solution converting a 12V rail to a 5V rail. The ISL85403 also can be used for a two-stage solution to step down a 24V rail to a 5V rail.

Features and Specifications of ISL8018

  • Delivers high peak efficiency up to 97%
  • Complete converter occupies less than 97mm2 of board space
  • ±10% output voltage margining
  • Output voltage is adjustable from 0.6V to VIN, with a fixed output voltage option
  • Adjustable current limit
  • External synchronization up to 4MHz, with master-to-slave phase shifting capability
  • Adjustable switching frequency from 500kHz to 4MHz, with default at 1MHz
  • Start-up with pre-bias output, internal soft start – 1ms or adjustable, internal/external compensation
  • Soft stop output discharge during disabled
  • Peak current limiting, hiccup mode short circuit protection and overtemperature protection
  • SYNCIN /SYNCOUT option to create phase-shift
  • 3 x 4mm, 20-lead QFN package

Features and Specifications of ISL80030, ISL80030A, ISL80031, ISL80031A

  • Deliver high peak efficiency up to 95%, with 3A maximum output current
  • Switching frequency up to 2MHz
  • Provides quiescent current as low as 35μA
  • Selectable PFM or PWM operation
  • Short circuit protection, and overcurrent, negative current, over-temperature/thermal protection
  • Internal soft start and soft stop
  • VIN under-voltage lockout and VOUT over-voltage protection
  • Less than 64mm2 of board space for complete converter
  • 2 x 2mm, 8-pin DFN package