Dual/n-Phase Buck PWM Controller with Integrated Drivers

The ISL8126 integrates two voltage-mode PWM leading-edge modulation control with input feed-forward synchronous buck PWM controllers to control dual independent voltage regulators or a 2-phase single output regulator. It also integrates current sharing control for the power module to operate in parallel, which offers high system flexibility. The ISL8126 integrates an internal linear regulator, which generates IC’s bias voltages for applications with only one single supply rail. The internal oscillator is adjustable from 150kHz to 1. 5MHz, and is able to synchronize to an external clock signal for frequency synchronization and phase paralleling applications. Its PLL circuit can output a phase-shift-programmable clock signal for the system to be expanded to 3-, 4-, 6- and 12- phases with desired interleaving phase shift. The ISL8126’s Fault Spreading feature protects any channel from overloading/stressing due to system faults or phase failure. The undervoltage fault protection features are also designed to prevent a negative transient on the output voltage during falling down. This eliminates the Schottky diode that is used in some systems for protecting the load device from reversed output voltage damage.