LT8645S
LT8645S is 8A Synchronous Step-Down Silent Switcher manufactured by Analog Devices.
FEATURES n Silent Switcher®2 Architecture n Ultralow EMI Emissions on Any PCB n Eliminates PCB Layout Sensitivity n Internal Bypass Capacitors Reduce Radiated EMI n Optional Spread Spectrum Modulation n High Efficiency at High Frequency n Up to 95% Efficiency at 1MHz, 12VIN to 5VOUT n Up to 94% Efficiency at 2MHz, 12VIN to 5VOUT n Wide Input Voltage Range: 3.4V to 65V n Ultralow Quiescent Current Burst Mode Operation n 2.5μA IQ Regulating 12VIN to 3.3VOUT (LT8645S) n Output Ripple < 10m VP-P n External pensation: Fast Transient Response and Current Sharing (LT8646S) n Fast Minimum Switch On-Time: 40ns n Low Dropout Under All Conditions: 60m V at 1A n Adjustable and Synchronizable: 200k Hz to 2.2MHz n Peak Current Mode Operation n Output Soft-Start and Tracking n Small 32-Lead 6mm × 4mm LQFN Package n AEC-Q100 Qualified for Automotive Applications
APPLICATIONS n Automotive and Industrial Supplies n General Purpose Step-Down n GSM Power Supplies
DESCRIPTION
The LT®8645S/LT8646S synchronous step-down regulator features second generation Silent Switcher architecture designed to minimize EMI 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 easy to achieve advertised EMI performance by eliminating layout sensitivity.
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. The LT8646S has external pensation to enable current sharing and fast transient response 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.
INTERNAL...