Features

• Wide Output Voltage Range: 0.8V ≤ V_OUT ≤ 10V
• Ultralow Operating I_Q: 30µA (One Channel On)
• Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
• OPTI-LOOP Compensation Minimizes C_OUT
• ±1% Output Voltage Accuracy
• Wide V_IN Range: 4V to 36V Operation
• Phase-Lockable Fixed Frequency 140kHz to 650kHz
• Selectable Continuous, Pulse Skipping or Low Ripple Burst Mode Operation at Light Loads
• Dual N-Channel MOSFET Synchronous Drive
• Very Low Dropout Operation: 99% Duty Cycle
• Adjustable Output Voltage Soft-Start or Tracking
• Output Current Foldback Limiting
• Power Good Output Voltage Monitor
• Output Overvoltage Protection
• Low Shutdown I_Q: 4µA
• Internal LDO Powers Gate Drive from V_IN or V_OUT
• Small 5mm × 5mm QFN Package

Typical Application

Description

The LTC3826 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 650kHz. 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 30μA no-load quiescent current extends operating life 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 LTC3826 features a precision 0.8V reference and a power good output indicator. A wide 4V to 36V input supply range encompasses all battery chemistries.

Independent TRACK/SS pins for each controller ramp the output voltage 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. For a leaded package version (28-lead SSOP), see the LTC3826-1 data sheet.