Featuring a input voltage range of 4.5 to 15 V, the Vishay Siliconix SiP12109 4-A synchronous buck regulator offers programmable switching frequencies of up to 1.5 MHz. Thanks to the high switching frequencies, the device will suit point-of-load regulation and 5- and 12-V rails in space-constrained computing, consumer electronics, telecom, and industrial applications. Within a 3- by 3-mm QFN-16 package, the regulator integrates both high- and low-side power MOSFETs. The MOSFETs offer a peak efficiency of up to 95% while a power-saving mode improves light-load efficiency, enabling high efficiencies over the entire load range. Output voltage is adjustable down to 0.6 with ±1% accuracy. A current-mode constant on-time (CM-COT) architecture, which enhances stability, accelerates transient response with minimized output capacitance and tight ripple regulation at very light loads. Protection includes output undervoltage and overvoltage, thermal shutdown, input undervoltage lockout, internal soft-start, and a power-good indicator.