GENERAL DESCRIPTION
The LT®8638-2 synchronous step-down regulator
features the Silent Switcher® architecture designed to
minimize EMI emissions while delivering high efficiency
at high switching frequencies. This performance makes
the LT8638-2 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 25ns minimum ontime
allows high step down ratios even at high switching
frequencies. External compensation through the VC pin
allows for fast transient response. PolyPhase operation
allows multiple LT8638-2 regulators to run with
interleaving phase shift to provide more output current.
Burst Mode operation enables low 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 through the SS pin, and an accurate input
voltage UVLO threshold can be set using the EN/UV pin.

FEATURES
 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 94% Efficiency at 2MHz, 12VIN to 5VOUT
 Wide Input Voltage Range: 2.8V to 42V
 10A Maximum Continuous, 12A Peak Transient
Output
 Fast Transient Response with External
Compensation
 Low Quiescent Current Burst Mode® Operation
 90μA IQ Regulating 12VIN to 5VOUT
 Output Ripple < 10mVP-P
 Reference Accuracy: ±1% Over Temperature
 Fast Minimum Switch On-Time: 25ns
 PolyPhase® Operation: Up to 12 Phases
 Low Dropout Under All Conditions: 45mV at 1A
 Adjustable and Synchronizable: 200kHz to 3MHz
 Output Soft-Start and Power Good
 Safely Tolerates High Reverse Current
 28-Lead 5mm × 4mm LQFN Package
 AEC-Q100 Qualified for Automotive Applications

APPLICATIONS
 Automotive and Industrial Supplies
 General Purpose Step-Down