INTERNATIONAL Rectifier, represented by Arrow Electronics , has introduced the IR3623, a high performance dual synchronous buck 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-to-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.
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.