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LTC3890 - 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller

The LTC®3890 is a high performance dual step-down switching regulator DC/DC controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase lockable frequency of up to 850kHz. Power loss and noise due to the ESR of the input capacitor are minimized by operating the two controller output stages out-of-phase.

The 50μA no-load quiescent current extends operating run time in battery-powered systems. OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3890 features a precision 0.8V reference and power good output indicators. A wide 4V to 60V 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 conduction mode at light loads. For a leaded package version (28-lead Narrow SSOP), see the LTC3890-1 data sheet.

Features Wide VIN Range: 4V to 60V (65V Abs Max) Low Operating IQ: 50μA (One Channel On) Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V RSENSE or DCR Current Sensing Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise Phase-Lockable Frequency (75kHz to 850kHz) Programmable Fixed Frequency (50kHz to 900kHz) Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Loads Selectable Current Limit Very Low Dropout Operation: 99% Duty Cycle Adjustable Output Voltage Soft-Start or Tracking Power Good Output Voltage Monitors Output Overvoltage Protection Low Shutdown IQ : < 14μA Internal LDO Powers Gate Drive from VIN or EXTVCC No Current Foldback During Start-Up Small Low Profile (0.75mm) 5mm × 5mm QFN Package Typical Application

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

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