The ISL6557A is a multi-phase PWM controller for core-voltage regulation. It drives up to four interleaved synchronous-rectified buck-converter channels in parallel. The multi-phase buck converter architecture uses interleaved timing to multiply ripple frequency and reduce input and output ripple currents. Lower ripple results in lower total component cost, reduced dissipation, and smaller implementation area. The ISL6557A also features Dynamic-VID™ technology, allowing seamless on-the-fly VID changes with no need for any additional external components. It provides fast and reliable dynamic VID changes with no output voltage overshoot or undershoot. The RGND and VSEN pins provide inputs for differential remote voltage sensing to improve regulation and protection accuracy.
The ISL6557A provides core‑voltage regulation by driving up to four interleaved synchronous‑rectified buck‑converter channels in parallel. It is pre‑configured for 4‑phase operation but can be set to 2‑ or 3‑phase mode, and its switching frequency is adjustable from 50 kHz to 6 MHz.
Key features include Dynamic‑VID technology, differential remote‑sense inputs (RGND, VSEN), programmable power‑on bias, and over‑current protection. The device is offered in a 24‑lead SOIC package and is available in Pb‑free versions.
| VID input range | 0.800 V to 1.550 V in 25 mV steps |
|---|---|
| Enable threshold (EN) rising | 1.206 V typical |
| Power‑On Reset threshold (VCC) rising | 4.25 V min |
| Overcurrent trip level | -90 pA min |
| Overvoltage threshold (VSEN) rising | 2.04 V typical |
It is pre‑configured for 4‑phase operation but can be set to 2‑ or 3‑phase operation.
A resistor connected between the FS pin and ground sets the switching frequency; a larger resistor gives a lower frequency.
They provide inputs for differential remote‑voltage sensing, improving regulation and protection accuracy.
The EN pin can be used with an external resistor divider to set the power‑on voltage level.