The LTC3615/LTC3615-1 are dual 3A synchronous stepdown regulators using a current mode, constant-frequency architecture. The DC supply current is only 130?A (Burst Mode operation at no-load) while maintaining the output voltages, dropping to zero current in shutdown. The 2.25V to 5.5V input supply range makes the parts ideally suited for single Li-Ion applications. 100% duty cycle capability provides low dropout operation, which extends operating time in battery-operated systems.The operating frequency is externally programmable up to 4MHz, allowing the use of small surface mount inductors. 0?, 90?, or 180? (LTC3615) or 140?/180? (LTC3615-1) of phase shift between the two channels can be selected to minimize input current ripple and output voltage ripple in a dual 3A or single 6A output configuration. Programmable slew rate limiting reduces EMI, and external synchronization can be applied up to 4MHz.The internal synchronous switches increase efficiency and eliminate the need for external catch diodes, saving external components and board space.The LTC3615/LTC3615-1 are offered in leadless 24-pin 4mm ? 4mm QFN and thermally enhanced 24-pin eTSSOP packages.Applications Point-of-Load Supplies Distributed Power Supplies Portable Computer Systems DDR Memory Termination Handheld Devices

DC1584A: Demo Board for the LTC4070 Li-Ion/Polymer Shunt Battery Charger System.

Demonstration Circuit DC1658A is a 20V High Efficiency Nanopower Step-Down Regulator featuring the LTC3388-1/ LTC3388-3. The LTC3388 is an ultralow quiescent current power supply designed to regulate the output voltage by means of a nanopower high efficiency synchronous buck regulator. The input current is only 720nA typical at no load while maintaining output voltage regulation, capable of supplying 50mA of load current. The LTC3388-1/ LTC3388-3 also in-corporates an accurate undervoltage lockout feature to disable the converter and maintain a low quiescent current state when the input voltage falls below 2.3V. In regulation, the LTC3388-1/LTC3388-3 enter a sleep state in which both input and output quiescent currents are minimal. The buck converter turns on and off as needed to maintain regulation. An additional standby mode disables the buck switching while the  output is in regulation for short duration loads requiring low ripple.

The LTC3621/LTC3621-2 is a high efficiency 17V, 1A synchronous monolithic step-down regulator. The switching frequency is fixed to 1MHz or 2.25MHz with a ?40% synchronizing range. The regulator features ultralow quiescent current and high efficiencies over a wide VOUT range.The step-down regulator operates from an input voltage range of 2.7V to 17V and provides an adjustable output range from 0.6V to VIN while delivering up to 1A of output current. A user-selectable mode input is provided to allow the user to trade off ripple noise for light load efficiency; Burst Mode operation provides the highest efficiency at light loads, while pulse-skipping mode provides the lowest voltage ripple. The MODE pin can also be used to allow the user to sync the switching frequency to an external clock. LTC3621 Options Part Name Frequency VOUT LTC3621 1.00MHz Adjustable LTC3621-3.3 1.00MHz 3.3V LTC3621-5 1.00MHz 5V LTC3621-2 2.25MHz Adjustable LTC3621-23.3 2.25MHz 3.3 LTC3621-25 2.25MHz 5V APPLICATIONS Portable-Handheld Scanners Industrial and Embedded Computing Automotive Applications Emergency Radio

Demonstration circuit 1868A is a dual step-down DC/DC switching converter featuring the LTM8024 μModule regulator. The demo board is designed to deliver dual 5V/3A and 3.3V/3A outputs from a 7V to 40V input. The Silent Switcher® architecture minimizes EMI while achieving high efficiency at frequencies up to 3MHz. The modes of operation (Burst Mode or Discontinuous Mode/SYNC) are jumper selectable. Burst Mode operation improves efficiency at light loads. The LTM8024 is a fixed frequency PWM regulator with current mode control scheme. The switching frequency is set by an appropriate resistor (R11) from the RT pin to ground. The RUN pins (EN1/EN2 terminals) can be used to set the LTM8024 in micro power shutdown mode. The power good output of each channel (PG1 or PG2 terminal) will be low when that channel’s output voltage is outside of the ±7.5% regulation window. The LTM8024 data sheet gives a complete description of the operation and application information. The data sheet must be read in conjunction with this demo manual.

The LTC3899 is a high performance triple output (buck/ buck/boost) DC/DC switching regulator controller that drives all N-channel synchronous power MOSFET stages. The constant frequency current mode architecture allows a phase-lockable frequency of up to 850kHz. The LTC3899 operates from a wide 4.5V to 60V input supply range. When biased from the output of the boost converter or another auxiliary supply, the LTC3899 can operate from an input supply as low as 2.2V after start-up.The gate drive for the LTC3899 can be programmed from 5V to 10V to allow the use of logic-level or standard-level FETs and to maximize efficiency. Internal switches in the top gate drivers eliminate the need for external bootstrap diodes. The 29?A no-load quiescent current extends operating run time in battery-powered systems. OPTI-LOOP? compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values.Applications Automotive Always-On and Start-Stop Systems Distributed DC Power Systems Multioutput Buck-Boost Applications

DC194A-B: Demo Board for the LT1317 Micropower, 600kHz PWM DC/DC Converters.

The LT8310 is a simple-to-use resonant reset forward converter controller that drives the gate of a low side N-channel MOSFET from an internally regulated 10V supply. The LT8310 features duty mode control that generates a stable, regulated, isolated output using a single power transformer. With the addition of output voltage feedback, via opto-coupler (isolated) or directly wired (nonisolated), current mode regulation is activated, improving output accuracy and load response. The flexibility to choose transformer turns ratio makes high step-down or step-up ratios possible without operating at duty cycle extremes.The user can program the switching frequency from 100kHz to 500kHz to optimize efficiency, performance or external component size. A synchronous output is available for controlling secondary side synchronous rectification to improve efficiency. User programmable protection features include monitors on input voltage (UVLO and OVLO) and switch current (overcurrent limit). The LT8310 soft-start feature helps protect the transformer from flux saturation.Applications Industrial, Automotive and Military Systems 48V Telecommunication Isolated Power Supplies Isolated and Nonisolated DC/DC Converters

The LT3514 consists of three buck regulators (2A, 1A, 1A output current). The device has a wide operating input range of 3.2V to 36V. An on-chip boost regulator allows each channel to operate up to 100% duty cycle. The LT3514 is designed to minimize external component count and results in a simple and small application circuit.The LT3514 operates robustly in fault conditions. Cycleby- cycle peak current limit and catch diode current limit sensing protect the IC during overload conditions. Thermal shutdown protects the power switches at elevated temperatures. Soft-start helps control the peak inductor current during startup.The LT3514 also features output voltage tracking and sequencing, programmable frequency, programmable undervoltage lockout, and a power good pin to indicate when all outputs are in regulation.The LT3514 has one fewer channel (CH2) than the LT3504, and has one channel (CH3) that outputs 2A instead of 1A. The LT3514 in QFN is pin compatible with the LT3504. The LT3504 provides four 1A outputs.Applications Automotive Battery Regulation Industrial Control Supplies Wall Transformer Regulation Distributed Supply Regulation

The LTC3774 is a dual PolyPhase? current mode synchronous step-down switching regulator controller that drives power blocks, DRMOS or external gate drivers and power MOSFETs. It offers an LTC-proprietary technique that enhances the signal-to-noise ratio of the current sense signal, allowing the use of inductors with very low DC winding resistances as the current sense element for maximum efficiency and reduced jitter.The maximum current sense voltage is programmable from 10mV to 30mV. High speed, low offset remote sense differential amplifiers and a precise 0.6V reference provide accurate output voltages between 0.6V and 3.5V from a wide 4.5V to 38V input supply range. Soft recovery from output shorts or overcurrent minimizes output overshoot. Burst Mode? operation, continuous and pulse-skipping modes are supported. The constant operating frequency can be synchronized to an external clock or linearly programmed from 200kHz to 1.2MHz. Up to six LTC3774 controllers can be paralleled for 1-, 2-, 3-, 4-, 6-, 8- or 12-phase operation.The LTC3774 is available in a 36-lead (5mm ? 6mm) QFN package.Applications Computer Systems Telecom and Datacom Systems Industrial Equipment DC Power Distribution Systems