LTC3850-2 - Dual, 2-Phase Synchronous Step-Down Switching Controller

The LTC3850-2 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 780kHz. Power loss and supply noise are minimized by operating the two controller output stages out of phase. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3850-2 features a precision 0.8V reference and a power good output indicator. A wide 4V to 30V input supply range encompasses 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 current mode and allows the IC to be synchronized to an external clock. The LTC3850-2 is identical to the LTC3850-1, except they have different pin assignments.

Features

Dual, 180° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
High Efficiency: Up to 95%
RSENSE or DCR Current Sensing
±1% 0.8V Output Voltage Accuracy
Phase-Lockable Fixed Frequency 250kHz to 780kHz
Supports Pre-Biased Output
Dual N-Channel MOSFET Synchronous Drive
Wide VIN Range: 4V to 30V Operation
Adjustable Soft-Start Current Ramping or Tracking
Foldback Output Current Limiting
Output Overvoltage Protection
Power Good Output Voltage Monitor
28-Pin Narrow SSOP Package