LTC3858 Datasheet | Linear Technology

Features n Low Operating IQ: 170μA (One Channel On) n Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V n Wide VIN Range: 4V to 38V n RSENSE or DCR Current Sensing n Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise n OPTI-LOOP® pensation Minimizes COUT n Phase-Lockable Frequency (75k Hz-850k Hz) n Programmable Fixed Frequency (50k Hz-900k Hz) n Selectable Continuous, Pulse-Skipping or Burst Mode® Operation at Light Loads n Very Low Dropout Operation: 99% Duty Cycle n Adjustable Output Voltage Soft-Start n Power Good Output Voltage Monitor n Output Overvoltage Protection n Output Latch-Off Protection During Short Circuit n Low Shutdown IQ: 8μA n Internal LDO Powers Gate Drive from VIN or EXTVCC n No Current Foldback During Start-Up n Small 5mm × 5mm QFN Package APPLICATIONS n Automotive Systems n Battery Operated Digital Devices n Distributed DC Power Systems Low IQ, Dual 2-Phase Synchronous Step-Down Controller DESCRIPTION The LTC®3858 is a high performance dual step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of up to 850k Hz. Power loss and noise due to the input capacitor ESR are minimized by operating the two controller outputs out of phase. The 170μA no-load quiescent current extends operating life in battery-powered systems. OPTI-LOOP pensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3858 Features a precision 0.8V reference and a power good output indicator. A wide 4V to 38V input supply range enpasses a wide range of intermediate bus voltages and battery chemistries. Independent soft-start pins for each controller ramp the output voltages during start-up. The output latch-off feature protects the circuit in short-circuit conditions. For a leaded 28-lead SSOP package with a fixed current limit and one PGOOD...