LTC3858-2 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 or Tracking n Power Good Output Voltage Monitor n Low Shutdown IQ: 8μA n Internal LDO Powers Gate Drive from VIN or EXTVCC n No Current Foldback During Start-Up n 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®3858-2 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 LTC3858-2 differs from the LTC3858 by having the overvoltage protection crowbar and short-circuit latchoff disabled. 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. Current foldback limits MOSFET heat dissipation during short-circuit conditions. L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, μModule, Poly Phase, Linear Technology and the Linear logo are registered...