Dual-output buck controller for point-of-load regulation
The Renesas ISL8120IRZ is a dual-output, two-phase synchronous buck PWM controller in a 32-QFN (5x5 mm) package. It steps down a 3 V to 5.6 V input rail to a regulated positive output using a transistor-driver stage and external MOSFETs. The part integrates current limit, enable, and power-good control features, and supports clock synchronization for interleaved operation.
Switching frequency and inductor sizing
A lower frequency (150 kHz) reduces switching losses and suits higher step-down ratios, while 1.5 MHz shrinks the inductor and output capacitor but demands tighter layout to keep switching-node ringing under control. The 90% maximum duty cycle gives headroom for low-dropout operation near the input rail.
Two-phase interleaved output
With two outputs and clock sync, the ISL8120IRZ can be configured as two independent single-phase regulators or as a single dual-phase rail. Interleaved two-phase operation cancels input ripple current and reduces output voltage ripple.
For current designs this means no imminent obsolescence risk.