Digital DC/DC PMBus Module Evaluation Board

The ISL8277MEVAL1Z evaluation board is a 3in x 4.5in 4-layer FR4 board with 2 oz. of copper in all layers. This board comes with a placeholder for pin-strap resistors to adjust the output voltage, switching frequency, input undervoltage (UVLO) protection threshold, and the device PMBus address. More configurations, such as soft-start and fault limits, can be easily programmed or changed using a PMBus compliant serial bus interface.

The ISLUSBEVAL1Z (USB to PMBus adapter) is provided with this board, which connects the evaluation board to a PC to activate the PMBus communication interface. The PMBus command set is accessed by using the PowerNavigator™ evaluation software from a PC running Microsoft Windows.

The ISL8277M (25A) is a step-down DC/DC power supply module with an integrated digital PWM controller, synchronous power switches, an inductor, and passives. Only bulk input and output capacitors are needed to finish the design. The 25A of continuous output current can be delivered without the need for airflow or a heatsink. The device uses ChargeMode™ control architecture, which responds to a transient load within a single switching cycle.