Analog Devices Inc./Maxim Integrated

The LTC3836 is a 2-phase dual output synchronous step-down switching regulator controller with tracking that drives external N-channel power MOSFETs using few external components. The constant-frequency current mode architecture with MOSFET VDSsensing eliminates the need for sense resistors and improves efficiency. The power loss and noise due to the ESR of the input capacitance are minimized by operating the two controllers out-of-phase. Pulse-skipping operation provides high efficiency at light loads. The 97% duty cycle capability provides low dropout operation, extending operating time in battery-powered systems.The operating frequency is selectable from 300kHz to 750kHz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications, the LTC3836 operating frequency can be externally synchronized from 250kHz to 850kHz.The LTC3836 features an internal 1ms soft-start that can be extended with an external capacitor. A tracking input allows the second output to track the first during start-up.The LTC3836 is available in the tiny thermally enhanced (4mm × 5mm) QFN and 28-lead narrow SSOP packages.ApplicationsGeneral Purpose 3.3V to 1.X SuppliesSingle Lithium-Ion Powered DevicesDistributed DC Power Systems

The LTC3838-2 is a dual-channel, PolyPhase®synchronous step-down DC/DC switching regulator controller. Two independent channels drive all N-channel power MOSFETs. The two channels can also be combined into a multiphase single output configuration with external reference.The controlled on-time, valley current mode control architecture allows for not only fast response to transients without a clock delay, but also constant frequency switching at a steady-load condition. Its proprietary load-release transient detection feature (DTR) significantly reduces overshoot at low output voltages.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 RangeApplicationsPower for ASICs with Dynamic Voltage ScalingLow Voltage, High Current, High Step-Down Ratio Converters That Demand Tight Transient Regulation

The LTC3838-2 is a dual-channel, PolyPhase®synchronous step-down DC/DC switching regulator controller. Two independent channels drive all N-channel power MOSFETs. The two channels can also be combined into a multiphase single output configuration with external reference.The controlled on-time, valley current mode control architecture allows for not only fast response to transients without a clock delay, but also constant frequency switching at a steady-load condition. Its proprietary load-release transient detection feature (DTR) significantly reduces overshoot at low output voltages.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 RangeApplicationsPower for ASICs with Dynamic Voltage ScalingLow Voltage, High Current, High Step-Down Ratio Converters That Demand Tight Transient Regulation