New Industry Products

IR POL Chipset Delivers 80A with Three Active Devices

March 30, 2006 by Jeff Shepard

International Rectifier (IR) has introduced the IR3623, a dual synchronous buck pulse-width modulation (pwm) control IC. Designed to be used with iP2003A iPOWIR™ integrated driver-MOSFET power building blocks, the chipset reduces component count and footprint in non-isolated, dc-dc buck converters delivering up to 80A in embedded networking and communications systems, point-of-load (POL) regulator modules and high-density blade servers.

The chipset can be configured to operate either as a high current (80A), single output converter, or as two independent 40A converters, switching 180 degrees out of phase. For example, in a 12V input, 1.75V output application with 500kHz switching frequency and a dual-channel configuration, the IR3623/iP2003A chipset achieves greater than 90 percent efficiency at 25A per channel without a heatsink. Compared to a similar converter made with a discrete power stage, the chipset requires 32% less board area as component count shrinks from eleven active devices to only three.

"Compared to standard discrete solutions, the IR3623/iP2003A chipset offers several benefits, including ease of design, reduced component count and space savings. In addition, the chipset is fully rated for switching frequencies up to 1MHz, enabling the highest levels of power density through the use of smaller output inductors and reduced number of output capacitors," said Faisal Ahmad, marketing manager for DC-DC Computing Products at International Rectifier.

The new pwm control IC offers a full array of protection features. For start-up, the IR3623 features a dedicated enable pin, an input under-voltage lockout circuit, and the ability to start-up into a pre-biased output voltage. In addition, the device features hiccup mode over-current protection, output over-voltage protection and thermal shutdown.

For true dual-channel operation, the chipset offers two independent programmable soft starts, and two independent power-good outputs. The IR3623 offers full support for output voltage tracking and power sequencing for multi-rail applications. Flexibility is included to allow for sequential, ratio metric or simultaneous voltage tracking of both channels without the need for any external components.

The iP2003A power stage block integrates a synchronous gate driver, high- and low-side power MOSFETs, a synchronous Schottky diode and passive components required for each converter phase, simplifying design and layout.

Pricing for the IR3623MPbF in 100-piece tubes and the IR3623MTRPbF in 3,000-piece Tape & Reel is US $1.80 for each device in 10,000-unit quantities. Pricing for the iP2003ATR begins at US $7.95 each in 10,000-unit quantities. Prices are subject to change. The devices are lead-free and are compliant with the Restriction of Hazardous Substances Directive (RoHS).