Features

• Wide V_IN Range: 4.5V to 38V, V_OUT: 0.6V to 5.5V
• ±0.67% Output Voltage Accuracy Over Temperature, Differential Output Voltage Sensing, Allowing Up to ±500mV Line Loss at Remote Ground
• Controlled On-Time, Valley Current Mode Control
• Fast Load Transient Response
• Detect Transient (DTR) Reduces V_OUT Overshoot
• Frequency Programmable from 200kHz to 2MHz, Synchronizable to External Clock
• t_ON(MIN) = 30ns, t_OFF(MIN) = 90ns
• Up to 12-Phase Operation
• R_SENSE or Inductor DCR Current Sensing
• Overvoltage Protection and Current Limit Foldback
• Power Good Output Voltage Monitor
• Output Voltage Tracking and Adjustable Soft Start-Up
• Thermally Enhanced 32-Pin (5mm × 5mm) QFN Package

Typical Application

Description

The LTC®3839 is a 2-phase, single-output PolyPhase® synchronous step-down switching regulator controller that drives all N-channel power MOSFETs. The controlled on-time, valley current mode control architecture allows for fast transient response and constant frequency switching in steady-state operation, independent of V_IN, V_OUT and load current. Its load-release transient detection feature significantly reduces overshoot at low output voltages.

Differential output voltage sensing, along with a precision internal reference, offers an accurate ±0.67% output regulation, even if the remote output ground deviates from local ground by ±500mV.

The switching frequency can be programmed from 200kHz to 2MHz with an external resistor and can be synchronized to an external clock. Very low t_ON and t_OFF times allow for near 0% and near 100% duty cycles, respectively. Voltage tracking soft start-up and multiple safety features are provided.