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