DESCRIPTION
The LT®8645S-2 synchronous step-down regulator features
Silent Switcher architecture designed to minimize
EMI emissions while delivering high efficiency at high
switching frequencies. This performance makes the
LT8645S-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 40ns minimum on-time allows high
step-down ratios even at high switching frequencies.
Burst Mode® operation enables ultralow standby current
consumption, pulse-skipping mode allows full switching
frequency at lower output loads, or spread spectrum
operation can further reduce EMI emissions.

FEATURES
- Silent Switcher® Architecture
- Ultralow EMI Emissions
- Optional Spread Spectrum Modulation
- High Efficiency at High Frequency
- Up to 95% Efficiency at 1MHz, 12VIN to 5VOUT
- Up to 94% Efficiency at 2MHz, 12VIN to 5VOUT
- Wide Input Voltage Range: 3.4V to 65V
- Ultralow Quiescent Current Burst Mode Operation
- 2.5μA IQ Regulating 12VIN to 3.3VOUT
- Output Ripple < 10mVP-P
- Fast Minimum Switch On-Time: 40ns
- Low Dropout Under All Conditions: 60mV at 1A
- Adjustable and Synchronizable: 200kHz to 2.2MHz
- Peak Current Mode Operation
- Output Soft-Start and Tracking
- Small 32-Lead 6mm × 4mm LQFN Package
- AEC-Q100 Qualified for Automotive Applications

APPLICATIONS
- Automotive and Industrial Supplies
- General Purpose Step-Down
- GSM Power Supplies