LT8640/LT8643 Synchronous Step-Down Regulator

Analog Devices' LT8640 and LT8643 synchronous step-down regulators feature second-generation Silent Switcher architecture, designed to minimize EMI/EMC emissions while delivering high efficiency at high switching frequencies. This includes the integration of bypass capacitors to optimize all the fast current loops inside and make it easier to achieve advertised EMI performance by reducing layout sensitivity. This performance makes the LT8640 and LT8643 ideal for noise-sensitive applications and environments.

The fast, clean, low-overshoot switching edges enable high-efficiency operation even at high switching frequencies, leading to a small overall solution size. Peak current mode control with a 30 ns minimum on-time allows high step-down ratios, even at high switching frequencies.

Burst Mode operation enables ultralow standby current consumption, forced continuous mode can control frequency harmonics across the entire output load range, or spread spectrum operation can further reduce EMI/EMC emissions. Soft-start and tracking functionality is accessed via the TR/SS pin, and an accurate input voltage UVLO threshold can be set using the EN/UV pin. A CLKOUT pin enables the synchronized of other regulators to the LT8640 and LT8643.