LTC3838-2 Series

Dual, Fast, Accurate Step-Down DC/DC Controller with External Reference Voltage and Dual Differential Output Sensing

Catalog

Dual, Fast, Accurate Step-Down DC/DC Controller with External Reference Voltage and Dual Differential Output Sensing

Part	Output Type	Mounting Type	Control Features	Frequency - Switching [Max]	Frequency - Switching [Min]	Package / Case	Output Phases	Output Configuration	Operating Temperature [Min]	Operating Temperature [Max]	Number of Outputs	Topology	Function	Voltage - Supply (Vcc/Vdd) [Max]	Voltage - Supply (Vcc/Vdd) [Min]	Supplier Device Package
Analog Devices LTC3838IUHF-2#PBF	Transistor Driver	Surface Mount	Enable Frequency Control Phase Control Power Good Soft Start Tracking	2 MHz	200 kHz	38-WFQFN Exposed Pad	2	Positive	-40 °C	125 ¯C	2	Buck	Step-Down	38 V	4.5 V
Analog Devices LTC3838IUHF#PBF	Transistor Driver	Surface Mount	Enable Frequency Control Phase Control Power Good Soft Start Tracking	2 MHz	200 kHz	38-WFQFN Exposed Pad	2	Positive	-40 °C	125 ¯C	2	Buck	Step-Down	38 V	4.5 V
Analog Devices LTC3838EFE#PBF	Transistor Driver	Surface Mount	Enable Frequency Control Phase Control Power Good Soft Start Tracking	2 MHz	200 kHz	38-TFSOP	2	Positive	-40 °C	125 ¯C	2	Buck	Step-Down	38 V	4.5 V	38-TSSOP-EP
Analog Devices LTC3838EFE#TRPBF	Transistor Driver	Surface Mount	Enable Frequency Control Phase Control Power Good Soft Start Tracking	2 MHz	200 kHz	38-TFSOP	2	Positive	-40 °C	125 ¯C	2	Buck	Step-Down	38 V	4.5 V	38-TSSOP-EP
Analog Devices LTC3838EUHF-2#PBF	Transistor Driver	Surface Mount	Enable Frequency Control Phase Control Power Good Soft Start Tracking	2 MHz	200 kHz	38-WFQFN Exposed Pad	2	Positive	-40 °C	125 ¯C	2	Buck	Step-Down	38 V	4.5 V
Analog Devices LTC3838IFE#TRPBF	Transistor Driver	Surface Mount	Enable Frequency Control Phase Control Power Good Soft Start Tracking	2 MHz	200 kHz	38-TFSOP	2	Positive	-40 °C	125 ¯C	2	Buck	Step-Down	38 V	4.5 V	38-TSSOP-EP
Analog Devices LTC3838IFE	Transistor Driver	Surface Mount	Enable Frequency Control Phase Control Power Good Soft Start Tracking	2 MHz	200 kHz	38-TFSOP	2	Positive	-40 °C	125 ¯C	2	Buck	Step-Down	38 V	4.5 V	38-TSSOP-EP

Catalog

Dual, Fast, Accurate Step-Down DC/DC Controller with External Reference Voltage and Dual Differential Output Sensing

Key Features

• Wide VINRange: 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 on Channel 1

• ±1% Output on the Independent 2nd Channel

• Controlled On-Time, Valley Current Mode Control

• Fast Load Transient Response

• Detect Transient (DTR) Reduces VOUTOvershoot

• Frequency Programmable from 200kHz to 2MHz, Synchronizable to External Clock

• tON(MIN)= 30ns, tOFF(MIN)= 90ns

• RSENSEor 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 and TSSOP packages

Description

The LTC3838 is a dual, 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 fast transient response and constant frequency switching in steady-state operation, independent of VIN, VOUTand 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 on Channel 1, even if the remote output ground deviates from local ground by ±500mV. The second channel can either provide an independent ±1% output, or together with the first channel of this controller, serve as one of the PolyPhase channels for a single-output voltage.The switching frequency can be programmed from 200kHz to 2MHz with an external resistor, and can be synchronized to an external clock. Very low tONand tOFFtimes allow for near 0% and near 100% duty cycles, respectively. Voltage tracking soft start-up and multiple safety features are provided.See below for a comparison of LTC3838, LTC3838-1 and LTC3838-2.Part NumberDescriptionLTC3838±0.67% Differential Output Voltage Accuracy Over Temperature on Channel 1, ±1% Output Regulation on Channel 2, Separate Per Channel 30mV to 100mV Current Sense Range ControlsLTC3838-1±0.67% Differential Output Voltage Accuracy Over Temperature on Both Channel 1 and Channel 2, Single Pin 30mV/60mV Current Sense Range ControlsLTC3838-2±0.67% Differential Output Voltage Accuracy With Internal Reference on Channel 1, ±4mV Differential with External Reference Voltage on Channel 2, Fixed 30mV Current Sense RangeApplicationsDistributed Power SystemsPoint-of-Load ConvertersComputing SystemsData Communication Systems