Linear Technology LTC3857EGN-1#PBF

Description
The LTC3857-1 is a high-performance dual step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. It features a constant frequency current mode architecture, allowing for a phase-lockable frequency of up to 850kHz. The out-of-phase operation of the two controller output stages minimizes power loss and noise due to the ESR of the input capacitor.
The LTC3857-1 has a low no-load quiescent current of 50µA, extending operating life in battery-powered systems. It features a precision 0.8V reference and a power good output indicator. The wide 4V to 38V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries.
Independent TRACK/SS pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.

Features
Low Operating lo: 50µA (One Channel On)
Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
Wide VIN Range: 4V to 38V
RSENSE or DCR Current Sensing
Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
OPTI-LOOP Compensation Minimizes Cout
Phase-Lockable Frequency (75kHz-850kHz)
Programmable Fixed Frequency (50kHz-900kHz)
Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode Operation at Light Loads
Very Low Dropout Operation: 99% Duty Cycle
Adjustable Output Voltage Soft-Start or Tracking
Power Good Output Voltage Monitor
Output Overvoltage Protection
Low Shutdown lo: <8μA
Internal LDO Powers Gate Drive from VIN or EXTVCC
No Current Foldback During Start-Up
Narrow SSOP Package

Applications
Automotive Always-On Systems
Battery Operated Digital Devices
Distributed DC Power Systems