LTC3839 - Fast, Accurate, 2-Phase, Single-Output Step-Down DC/DC Controller with Differential Output Sensing

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 VIN, VOUT 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 tON and tOFF times allow for near 0% and near 100% duty cycles, respectively. Voltage tracking soft start-up and multiple safety features are provided.

Features

Wide VIN Range: 4.5V to 38V, VOUT: 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 VOUT Overshoot
Frequency Programmable from 200kHz to 2MHz, Synchronizable to External Clock
tON(MIN) = 30ns, tOFF(MIN) = 90ns
Up to 12-Phase Operation
RSENSE 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