Dual synchronous buck regulator features integrated MOSFETs and high efficiency user-configurable power blocks for quick design time

The ISL65426 switches at a fixed frequency of 1MHz and utilises current-mode control with integrated compensation to minimise the size and number of external components and provide excellent transient response. The internal synchronous power switches are optimised for good thermal performance and high efficiency.
The device facilitates a quick power supply design through its unique architecture of six, 1A user-configurable power blocks. With its ease of configurability, high integration and advanced monitoring and protection features, the ISL65426 represents a complete and compact power solution.
The ISL65426 operates over an input voltage range of 2.375V to 5.5V. This single-chip power solution provides two output voltages that are selectable or externally adjustable from 1V to 80% of the supply voltage while delivering up to 6A of total output current. The two PWMs are synchronized 180 degrees out of phase, reducing EMI and the RMS input current and ripple voltage thus reducing the size of input filter components.
The ISL65426’s unique power block architecture allows partitioning of the six 1A capable blocks to support one of four output configuration options (5A:1A, 4A:2A, 3A:3A, and 2A:4A). One master power block is associated with each synchronous converter channel. Four floating slave power blocks allow the user to assign them to either channel. Proper external configuration of the power blocks is verified internally prior to soft-start initialisation.
Independent enable inputs allow for sequencing soft-start intervals of the two converter channels. A third enable input allows additional sequencing for multi-input bias supply designs. Individual power good indicators (PG1, PG2) signal when the output voltage is within regulation window.
The ISL65426 integrates protection for both synchronous buck regulator channels. The fault conditions include overcurrent, undervoltage, and IC thermal monitor. A thermally enhanced QFN package, the high 1MHz switching frequency and reduced BOM component count results in a compact power supply solution for the VCCINT and VCCIO supply rails of an FPGA or CPLD.
Other key features include a high efficiency of up to 95%, ±1% system accuracy over temperature, programmable 2-bit VID input, ultra-compact DC/DC converter design, stable operation with ceramic capacitors, excellent dynamic response, independent output digital soft-start, power good output voltage monitor, and short-circuit protection.
Target applications include FPGA, CPLD, DSP, and CPU core and I/O voltages, Xilinx Spartan III™, Virtex II™, Virtex II Pro™, Virtex 4™, Altera Stratix™, Stratix II™, Cyclone™, Cyclone II™, Actel Fusion™, LatticeSC™, LatticeEC™, low-voltage, high-density distributed power systems, point-of-load regulation, distributed power systems, set-top boxes, routers, and switchers.
Intersil’s ISL65426 is available now in a 50-lead QFN package. Pb-free plus anneal is also available (RoHS compliant).