The LT8640 is a 42V, 5A synchronous step-down regulator that features Silent Switcher architecture. Silent Switcher minimizes EMI emissions without metal shielding or slow switching edges. This results in good EMI performance with high efficiency at high switching frequencies. Peak efficiency for a 12VIN to 5VOUT application is over 96% at 1MHz switching frequency, and almost 95% at 2MHz switching frequency. The 5A synchronous buck has a low 2.5µA quiescent current, wide input voltage range to 42V, and low minimum on-time and dropout—all in a small 3mm × 4mm QFN package.