LINEAR Manuals

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 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.

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

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.

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

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 LTC3703 is a synchronous step-down switching regulator controller from LTC company that can directly step down voltages up to 100V, making it ideal for telecom and automotive applications. The LTC3703 uses a constant frequency (up to 600kHz), voltage mode architecture to drive external N-channel MOSFETs. A precise internal reference provides 1% DC accuracy. A high bandwidth error amplifier and patented line feed forward compensation provide very fast line and load transient response. Strong 1Ω gate drivers allow the LTC3703 to drive multiple MOSFETs for higher current applications. The operating frequency is user programmable from 100kHz to 600kHz and can also be synchronized to an external clock for noise-sensitive applications. Current limit is programmable with an external resistor and utilizes the voltage drop across the synchronous MOSFET to eliminate the need for a current sense resistor.

LTC3728 is a high-efficiency dual 5V/3.3V step-down converter with ±1% output voltage accuracy.

LTC485 is a low power differential bus/line transceiver designed for multipoint data transmission standard RS485 applications with extended common mode range (12V to –7V). It also meets the requirements of RS422. CMOS design offers significant power savings over its bipolar counterpart without sacrificing ruggedness against overload of ESD damage. The driver and receiver feature three-state outputs, with the driver outputs maintaining high impedance over the entire common mode range. Excessive power dissipation caused by bus contention or faults is prevented by a thermal shutdown circuit which forces the driver outputs into a high impedance state. The receiver has a fail-safe feature which guarantees a high output state when the inputs are left open. The LTC485 is fully specified over the commercial and extended industrial temperature range.

The LT ®1640AL/LT1640AH are 8-pin, negative voltage Hot Swap TM controllers that allow a board to be safely inserted and removed from a live backplane

High Voltage, 1.5A, 500kHz Step-Down Switching Regulators

The LTC1235 is a microprocessor supervisory circuit provides complete power supply monitoring and battery control functions for microprocessor reset, battery backup, RAM write protection, power failure warning and watchdog timing.

The LTC3703 is a synchronous step-down switching regulator controller that can directly step down voltages from up to 100V, making it ideal for telecom and automotive applications. It drives external N-channel MOSFETs using a constant frequency (up to 600kHz), voltage mode architecture. A precise internal reference provides 1% DC accuracy. It has a high bandwidth error amplifier and patented line feed-forward compensation for fast line and load transient response. The LTC3703 has strong 1Ω gate drivers for higher current applications. The operating frequency is user programmable from 100kHz to 600kHz and can be synchronized to an external clock for noise-sensitive applications. Current limit is programmable with an external resistor and utilizes the voltage drop across the synchronous MOSFET to eliminate the need for a current sense resistor. For applications requiring up to 60V operation with logic-level MOSFETs, refer to the LTC3703-5 data sheet.