ISL6308A

Description

The ISL6308A is a three-phase PWM control IC with integrated MOSFET drivers. The ISL6308A  provides a precision voltage regulation system for multiple applications including, but not limited to, high current low voltage point-of-load converters, embedded applications and other general purpose low voltage medium to high current applications.The integration of power MOSFET drivers ISL6308A  into the controller IC ISL6308A  marks a departure from the separate PWM controller and driver configuration of previous multi-phase product families. By reducing the number of external parts, this integration allows for a cost and space saving power management solution. Output voltage can be programmed using the on-chip DAC or an external precision reference. A two bit code programs the DAC reference to one of 4 possible values (0.6V, 0.9V,1.2V and 1.5V). A unity gain, differential amplifier is provided for remote voltage sensing, compensating for any potential difference between remote and local grounds. The output voltage of ISL6308A can also be offset through the use of single external resistor. An optional droop function is also implemented and can be disabled for applications having less stringent output voltage variation requirements or experiencing less severe step loads. A unique feature of the ISL6308A is the combined use of both DCR and rDS(ON) current sensing. Load line voltage positioning and overcurrent protection are accomplished through continuous inductor DCR current sensing, while rDS(ON) current sensing is used for accurate channel-current balance. Using both methods of current sampling utilizes the best advantages of each technique. Protection features of this controller IC include a set of sophisticated overvoltage and overcurrent protection. Overvoltage results in the converter turning the lower MOSFETs ON to clamp the rising output voltage and protect the load. An OVP output is also provided to drive an optional crowbar device. The overcurrent protection level is set through a single external resistor. Other protection features of ISL6308A  include protection against an open circuit on the remote sensing inputs. Combined, these features provide advanced protection for the output load.