Features

• Wide V_IN Range: 4.5V to 38V, V_OUT: 0.6V to 5.5V
• Two Independent Channels: Dual/Single Output
• Output Voltage Regulation Accuracy: ±0.67% (V_OUT1) and ±0.75% (V_OUT2) Over Temperature
• Differential Remote Output Sensing: Up to ±500mV (V_OUT1) and ±200mV (V_OUT2) Ground Deviations
• Controlled On-Time, Valley Current Mode Control
• Fast Load Transient Response Without Clock Delay
• Detect Transient Release (DTR) Reduces V_OUT Overshoot
• Frequency Programmable from 200kHz to 2MHz, Synchronizable to External Clock
• t_ON(MIN) = 30ns, t_OFF(MIN) = 90ns
• 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 38-Pin (5mm × 7mm) QFN Package

Typical Application

Description

The LTC®3838-1 is a dual-channel, PolyPhase® synchronous step-down DC/DC switching regulator controller. Two independent channels drive all N-channel power MOSFETs. The controlled on-time, valley current mode control architecture allows for not only fast response to transients without clock delay, but also constant frequency switching at steady load condition. Its proprietary loadrelease transient detection feature (DTR) significantly reduces overshoot at low output voltages.

A precision internal reference enables accurate differential output regulation. The dual channels can either provide two independent output voltages, or be combined into multiphase single-output configuration.

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.

See Table 1 for a comparison of LTC3838, LTC3838-1 and LTC3838-2.