LTC3850-1 Datasheet | Linear Technology

LTC3850/LTC3850-1 Dual, 2-Phase Synchronous Step-Down Switching Controller Features n Dual, 180° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise n High Efficiency: Up to 95% n RSENSE or DCR Current Sensing n ±1% 0.8V Output Voltage Accuracy n Phase-Lockable Fixed Frequency 250k Hz to 780k Hz n Supports Pre-Biased Output n Dual N-Channel MOSFET Synchronous Drive n Wide VIN Range: 4V to 24V (30V for LTC3850I) Operation n Adjustable Soft-Start Current Ramping or Tracking n Foldback Output Current Limiting n Power Good Output Voltage Monitor n 28-Pin 4mm × 4mm, 4mm × 5mm QFN and Narrow SSOP Packages n AEC-Q100 Qualified for Automotive Applications APPLICATIONS n Notebook and Palmtop puters n Portable Instruments n Battery-Operated Digital Devices n DC Power Distribution Systems All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6304066, 6580258. DESCRIPTION The LTC®3850 is a high performance dual synchronous step-down switching regulator controller that drives all N-channel power MOSFET stages. A constant-frequency current mode architecture allows a phase-lockable frequency of up to 780k Hz. Power loss and supply noise are minimized by operating the two controller output stages out of phase. OPTI-LOOP® pensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3850 Features a precision 0.8V reference and a power good output indicator. A wide 4V to 24V (28V maximum/30V for LTC3850I) input supply range enpasses most battery chemistries and intermediate bus voltages. Independent TK/SS pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping mode, or continuous inductor...