The LTC1730 is a complete pulse charger for 1-cell lithium-ion batteries. When charging a depleted cell, the internal MOSFET is fully on allowing the current limited input power source to provide charge current to the battery, virtually eliminating heat generation in the charger.As the battery accepts charge and approaches the programmed voltage, the internal MOSFET begins switching off and on with the duty cycle gradually decreasing as the battery approaches a fully charged condition. A programmable timer ends the charge cycle. The end-of-charge condition is indicated at the CHRG pin when the average charge current falls to C/10. Removing the input voltage puts the LTC1730 into a sleep mode, dropping the battery current drain to less than 1?A (maximum).An external sense resistor limits the maximum charge current as a safety precaution against a user connecting a wall adapter with the incorrect or no current limit. The internal MOSFET prevents reverse battery current from flowing if the input voltage is shorted to ground, eliminating the need for a blocking diode.The LTC1730-4 is available in the 16-pin SSOP package and the LTC1730-4.2 is available in the 8-pin SO package.Applications Standalone Lithium-Ion Battery Charger Handheld Computers Cellular Telephones

The LTC1923 is a pulse width modulator intended for thermoelectric cooler (TEC) or heater applications requiring either unidirectional or bidirectional drive circuits. All of the necessary control circuitry and two sets of complementary output drivers are integrated into the LTC1923 to drive a full bridge, providing an efficient means of bidirectional current flow to the TEC. An accurate temperature control loop to stabilize the temperature of a laser diode system is easily achieved with the addition of just a few external components. Typical temperature setpoint accuracy of 0.1?C is achievable with the LTC1923. Adding an instrumentation amplifier front end allows setpoint stability of 0.01?C.The part features independent adjustable heating and cooling pulse-by-pulse current limit, current soft-start for controlled start-up, output slew rate control to reduce system noise, differential current sense and voltage amplifiers and a host of auxiliary circuits to protect the laser and provide redundant system monitoring.Applications Laser-Based Fiber Optic Links Medical Instruments CPU Temperature Regulators

DC391A-A: Demo Board for LTC5505 RF Power Detector with Buffered Output and >40dB Dynamic Range.

The LT1961 is a 1.25MHz monolithic boost switching regulator. A high efficiency 1.5A, 0.2? switch is included on the die together with all the control circuitry required to complete a high frequency, current-mode switching regulator. Current-mode control provides fast transient response and excellent loop stability.New design techniques achieve high efficiency at high switching frequencies over a wide operating voltage range. A low dropout internal regulator maintains consistent performance over a wide range of inputs from 24V systems to Li-Ion batteries. An operating supply current of 1mA maintains high efficiency, especially at lower output currents. Shutdown reduces quiescent current to 6?A. Maximum switch current remains constant at all duty cycles. Synchronization allows an external logic level signal to increase the internal oscillator from 1.5MHz to 2MHz.The LT1961 is available in an exposed pad, 8-pin MSOP package. Full cycle-by-cycle switch current limit protection and thermal shutdown are provided. High frequency operation allows the reduction of input and output filtering components and permits the use of chip inductors.Applications DSL Modems Portable Computers Battery-Powered Systems Distributed Power

DC442A: Demo Board for the LT1950 Single Switch PWM Controller with Auxiliary Boost Converter.

The LT1970A is a ?500mA power op amp with precise externally controlled current limiting. Separate control voltages program the sourcing and sinking current limit sense thresholds with 1% accuracy. Output current may be boosted by adding external power transistors.The circuit operates with single or split power supplies from 5V to 36V total supply voltage. In normal operation, the input stage supplies and the output stage supplies are connected (VCC to V+ and VEE to V?). To reduce power dissipation it is possible to power the output stage (V+, V?) from independent, lower voltage rails. The amplifier is unity-gain stable with a 3.6MHz gain-bandwidth product and slews at 1.6V/?s. The LT1970A can drive capacitive and inductive loads directly.Open-collector status flags signal current limit circuit activation, as well as thermal shutdown of the amplifier. An enable logic input puts the amplifier into a low power, high impedance output state when pulled low. Thermal shutdown and a ?800mA fixed current limit protect the chip under fault conditions.The LT1970A is packaged in a 20-lead TSSOP package with a thermally conductive copper bottom plate to facilitate heat sinking.Applications Automatic Test Equipment Laboratory Power Supplies Motor Drivers Thermoelectric Cooler Driver

DC459A Demo Board for: LT1946 1.2MHz Boost DC/DC Converter with 1.5A Switch and Soft-Start LT1946A 2.7MHz Boost DC/DC Converter with 1.5A Switch and Soft-Start

The LT5506 is a 40MHz to 500MHz monolithic integrated quadrature demodulator with variable gain amplifier (VGA), designed for low voltage operation. It supports standards that use a linear modulation format. The chip consists of a VGA, quadrature down-converting mixers and lowpass noise filters. The LO port consists of a divide-by-two stage and LO buffers. The IC provides all building blocks for IF down-conversion to I and Q baseband signals with a single supply voltage of 1.8V to 5.25V. The VGA gain has a linear-in- dB relationship to the control input voltage. Hard-clipping amplifiers at the mixer outputs reduce the recovery time from a signal overload condition. The lowpass filters reduce the out-of-band noise and spurious frequency components. The cut-off frequency of the noise filters is approximately 8.8MHz. The external 2xLO frequency is required to be twice the IF input frequency for the mixers. The standby mode provides reduced supply current and fast transient response into the normal operating mode when the I/Q outputs are AC-coupled to a baseband chip.Applications IEEE802.11 High Speed Wireless LAN Wireless Local Loop

The LT3430/LT3430-1 are monolithic buck switching regulators that accept input voltages up to 60V. A high efficiency 3A, 0.1? switch is included on the die along with all the necessary oscillator, control and logic circuitry. A current mode architecture provides fast transient response and excellent loop stability.Special design techniques and a new high voltage process achieve high efficiency over a wide input range. Efficiency is maintained over a wide output current range by using the output to bias the circuitry and by utilizing a supply boost capacitor to saturate the power switch. Patented circuitry* maintains peak switch current over the full duty cycle range. A shutdown pin reduces supply current to 30?A and a SYNC pin can be externally synchronized with a logic level input from 228kHz to 700kHz for the LT3430 or from 125kHz to 250kHz for the LT3430-1.The LT3430/LT3430-1 are available in a thermally enhanced 16-pin TSSOP package.Applications Industrial and Automotive Power Supplies Portable Computers Battery Chargers Distributed Power Systems

DC473A: Demo Board for the LTC1702A - Dual 550kHz Synchronous 2-Phase Switching Regulator Controller.