LINEAR Manuals

The LT ®1766/LT1766-5 is a 200kHz monolithic buck switching regulator that accepts input voltages up to 60V. The device features high efficiency, a 0.2 ohm switch, 1.5 ampere peak switch current and a constant 200 kHz switching frequency.

The LTC1148 series is a family of synchronous step-down switching regulator controllers featuring high efficiency, current-mode operation, and low power consumption.

The LT1004 is a 2-terminal bandgap reference diode designed to provide high accuracy and excellent temperature characteristics at very low operating currents. It has an initial accuracy of ±4mV, an operating current of 10µA, and can operate up to 20mA.

The LTC3719 is a 2-phase, VID programmable, synchronous step-down switching regulator controller that drives two N-channel external power MOSFET stages in a fixed frequency architecture. The 2-phase controller drives its two output stages out of phase at frequencies up to 300kHz to minimize the RMS ripple currents in both input and output capacitors. The 2-phase technique effectively multiplies the fundamental frequency by two, improving transient response while operating each channel at an optimum frequency for efficiency. Thermal design is also simplified. An operating mode select pin (FCB) can be used to select among three modes including Burst Mode operation for highest efficiency. An internal differential amplifier provides true remote sensing of the regulated supply’s positive and negative output terminals as required in high current applications. The RUN/SS pin provides soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when the overcurrent latchoff is disabled. OPTI-LOOP compensation allows the transient response to be optimized for a wide range of output capacitors and ESR values. 2-Phase, High Efficiency, Step-Down Controller for AMD Opteron CPUs.

Low-voltage single supply op amps LT1881/LT1882 feature high accuracy input performance and RRO output swing.

The LTC3718 is a 1.5V input voltage, synchronous buck/boost controller, for DDR/QDR memory termination. It features low input voltage, fast transient response, high efficiency, true current mode control and more.

The LTC ®1707 is a high efficiency monolithic current mode synchronous buck regulator using a fixed frequency architecture. The operating supply range is from 8.5V down to 2.85V, making it suitable for both single and dual lithium-ion battery-powered applications. Burst Mode op- eration provides high efficiency at low load currents. 100% duty cycle provides low dropout operation, extend- ing operating time in battery-powered systems. The switching frequency is internally set at 350kHz, allowing the use of small surface mount inductors. For noise sensitive applications it can be externally synchro- nized up to 550kHz. Burst Mode operation is inhibited during synchronization or when the SYNC/MODE pin is pulled low preventing low frequency ripple from interfer- ing with audio circuitry. Soft-start is provided by an external capacitor. The internal synchronous MOSFET switch increases effi- ciency and eliminates the need for an external Schottky diode, saving components and board space.

The LT1120 is a combination micropower positive regulator and free collector comparator on a single monolithic chip. With only 40µA supply current, the LT1120 can supply over 125mA of output current. Input voltage range is from 4.5V to 36V and dropout voltage is 0.6V at 125mA. Dropout voltage decreases with lower load currents. Also included on the chip is a class B output 2.5V reference that can either source or sink current. A shutdown pin allows logic shutdown of the output. The comparator can be used for system or battery monitoring. For example, the comparator can be used to warn of low system voltage. Frequency compensation of the comparator for amplifier applications can be obtained by adding external output capacitance. The 2.5V reference will source or sink current. This allows it to be used as a supply splitter or auxiliary output.

The LTC®1484 is a low power RS485 compatible transceiver with a fail-safe feature that guarantees a high receiver output state when the inputs are left open, shorted together or terminated with no signal present. The LTC1484 can also drive low cost residential telephone wires.

The LTC1142/LTC1142L/LTC1142HV are dual synchronous step-down switching regulator controllers featuring automatic Burst Mode™ operation to maintain high efficiencies at low output currents. The devices are composed of two separate regulator blocks, each driving a pair of external complementary power MOSFETs, at switching frequencies up to 250kHz, using a constant off-time current mode architecture providing constant ripple current in the inductor. The operating current level for both regulators is user programmable via an external current sense resistor. Wide input supply range allows operation from 3.5V* to 18V (20V maximum). Constant off-time architecture provides low dropout regulation limited only by the RDS(ON) of the external MOSFET and resistance of the inductor and current sense resistor. The LTC1142 series is ideal for applications requiring dual output voltages with high conversion efficiencies over a wide load current range in a small amount of board space. Dual Outputs: 3.3V and 5V or User Programmable Ultrahigh Efficiency: Over 95% Possible Current Mode Operation for Excellent Line and Load Transient Response High Efficiency Maintained over 3 Decades of Output Current Low Standby Current at Light Loads: 160µA/Output Independent Micropower Shutdown: IQ < 40µA Wide VIN Range

LTC3425 is a synchronous, 4-phase boost converter with output disconnect capable of operation below 1V input. It includes four N-channel MOSFET switches and four P-channel synchronous rectifiers for an effective RDS(ON) of 0.045Ω and 0.05Ω, respectively. 4-phase operation greatly reduces peak inductor currents, and capacitor ripple current, and increases effective switching frequency, minimizing inductor and capacitor sizes. True output disconnect eliminates inrush current and allows zero load current in shutdown. External Schottky diodes are not required.

The LTC1261 is a voltage inverter that can provide a regulated negative voltage from a single positive supply. It features adjustable or fixed output voltages, low output ripple, shutdown mode, and guaranteed output regulation.

The data sheet introduces the features and characteristics of LTC1876 high performance triple output switching regulator and step-up regulator. The chip uses dual phase, dual synchronous step-down switching controller, drives all N-channel synchronous power MOSFET stages, and an internal 1A, 36V step-up regulator provides the third output. The chip uses OPTI-LOOP compensation, which optimizes the transient response over a wide range of output capacitance and ESR values. Each controller's RUN/SS pin provides both soft-start and an optional timed, short-circuit shutdown function that can be configured to latch off one or both controllers. Current foldback provides additional short-circuit protection. In an overvoltage condition, the bottom MOSFET is latched on until VOUT returns to normal. The FCB pin can be used to inhibit Burst Mode operation or to enable regulation of a secondary output voltage. The step-up regulator operates at 1.2MHz, allowing the use of tiny low cost capacitors and inductors. In addition, its internal 1A switch allows high current outputs to be generated. Its current mode control scheme provides excellent line and load regulation.

The LTM4605 is a high efficiency switching mode buck-boost power supply from Philips. It operates over an input voltage range of 4.5V to 20V and supports an output voltage range of 0.8V to 16V. The maximum output current is 5A. This product uses a single inductor architecture, and the input voltage can be higher, lower, or equal to the output voltage. The LTM4605 uses a high switching frequency and current mode architecture, which provides a very fast transient response to line and load changes. The product also has overvoltage and foldback current protection. The LTM4605 is available in a small, thermally enhanced 15mm x 15mm x 2.8mm LGA package and is RoHS compliant.