42V, 5A/7A Peak Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current

The LT8636/LT8637 synchronous step-down regulator features Silent Switcher architecture designed to minimize EMI emissions while delivering high efficiency at high switching frequencies. Peak current mode control with a 30ns minimum on-time allows high step-down ratios even at high switching frequencies.

The LT8636’s ultralow 2.5µA quiescent current—with the output in full regulation—enables applications requiring highest efficiency at very small load currents. The LT8637 has external compensation to enable current sharing and fast transient response at high switching frequencies. A CLKOUT pin enables synchronizing other regulators to the LT8636/LT8637.

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 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.

APPLICATIONS

* Automotive and Industrial Supplies

* General Purpose Step-Down

* Silent Switcher® Architecture

* Ultralow EMI Emissions

* Optional Spread Spectrum Modulation

* High Efficiency at High Frequency

* Up to 96% Efficiency at 1MHz, 12VIN to 5VOUT

* Up to 95% Efficiency at 2MHz, 12VIN to 5VOUT

* Wide Input Voltage Range: 3.4V to 42V

* 5A Maximum Continuous, 7A Peak Transient Output