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2022-09-24 23:33:15
ISL6244 - Multiphase PWM Controller
The ISL6244 provides core voltage regulation, driving 24 interleaved synchronous rectification buck converter channels in parallel. Staggered channel timing results in increased ripple current thereby reducing input and output ripple frequency. Reduced component cost results in lower ripple, lower power dissipation, and a smaller implementation area. The ISL6244 uses cost and space-saving RDS(ON) sense channel current balancing, active voltage positioning, and overcurrent protection. The output voltage is monitored by an internal differential remote sense amplifier. High bandwidth error amplifier that drives the output voltage to match the reference voltage for programming the 5-bit DAC. The resulting compensation signal guides the creation of a pulse width modulated (PWM) signal to control the companion INTERSILMOSFET driver. The OFS pin allows direct offset of the voltage from 0V to 100mV using an external DAC resistor. The entire system is trimmed to ensure system accuracy of ±1%. Outstanding features of this controller IC include Dynamic VIDTM technology, which enables seamless on-the-fly VID changes without requiring any external components. Battery "feed-forward" is intended to facilitate conventional total input voltage variation control schemes. Output voltage "droop" or active voltage positioning is optional. When employed, it can reduce the size and cost of output capacitor requirements to support load transients. A threshold sensitive enable input allows the use of a separate power supply for startup coordination with Intersil's external resistor divider from the power supply to the MOSFET driver or any other device. Advanced overvoltage protection is achieved by casting on each stage of the step-down MOSFET to reduce the output voltage. Low voltage conditions are detected, but PWM operation is not affected. An overcurrent condition will cause a hiccupmode to repeatedly attempt to restart in response to the controller. After a failed start attempt, the controller locks up. A power good logic signal indicates when the converter output is between the UV and OV thresholds.