LINEAR Manuals

The LT1221 is a very high-speed operational amplifier with superior DC performance. It features reduced input offset voltage, lower input bias currents, and higher DC gain than devices with comparable bandwidth and slew rate. The circuit is a single gain stage that includes proprietary DC gain enhancement circuitry to obtain precision with high speed. The high gain and fast settling time make the circuit an ideal choice for data acquisition systems. The circuit is also capable of driving capacitive loads, making it useful in buffer or cable driver applications.

The LT1969 is an adjustable current version of the popular LT1886, a 200mA minimum output current, dual op amp with outstanding distortion performance. The adjustable current feature is highly desirable in applications where minimum power dissipation is required while still being able to provide adequate line termination. At nominal supply current, the amplifiers are gain of 10 stable and can easily be compensated for lower gains. The LT1969 features balanced high impedance inputs with 4µA input bias current and 4mV maximum input offset voltage. Single supply applications are easy to implement and have lower total noise than current feedback amplifier implementations. The output drives a 25Ω load to ±4.3V with ±6V supplies. On ±2.5V supplies, the output swings ±1.5V with a 100Ω load. The amplifier is stable with a 1000pF capacitive load making it useful in buffer and cable driver applications. The LT1969 is manufactured on Line.

The LTC4098 is a high efficiency USB PowerPathTM controller and full-featured Li-Ion/Polymer battery charger. It seamlessly manages power distribution from multiple sources including USB, wall adapter, automotive, firewire or other high voltage DC/DC converters, and a Li-Ion/Polymer battery. The LTC4098’s internal switching regulator automatically limits its input current for USB compatibility. For automotive and other high voltage applications, the LTC4098 interfaces with a Linear Technology external switching regulator to provide a high efficiency high voltage power path. Both the USB and the optional high voltage inputs feature Bat-Track optimized charging to provide maximum power to the application and ease thermal issues in high power density applications with input supplies from 5V to as high as 38V. An overvoltage circuit protects the LTC4098 from high voltage damage on the USB/Wall adaptor inputs with an N-channel FET and a resistor. The LTC4098 is available in the ultra-thin (0.55mm) 20-Lead 3mm × 4mm QFN surface mount package.

The LT3430/LT3430-1 are monolithic buck switching regulators that accept input voltages up to 60V. A high efficiency 3A, 0.1Ω 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 30µA 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.

The LT3430 is a high voltage, 3A, 200kHz step-down switching regulator with a wide input range, high efficiency, fast transient response, and excellent loop stability.

The LTC1415 is a 1.25MSPS, 12-bit sampling ADC that draws only 55mW from a single 5V supply and can operate with external or internal reference.

The LTC3727/LTC3727-1 are high efficiency dual 12V/5V step-down converters with features including wide output voltage range, out-of-phase controllers, OPTI-LOOP compensation, output voltage accuracy, and power good output voltage monitor.

The LTC3711 is a synchronous step-down switching regulator controller for CPU power. An output voltage between 0.925V and 2.000V is selected by a 5-bit code (Intel mobile VID specification). The controller uses a valley current control architecture to deliver very low duty cycles without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in VIN and VOUT. Discontinuous mode operation provides high efficiency operation at light loads. A forced continuous control pin reduces noise and RF interference and can assist secondary winding regulation by disabling discontinuous mode operation when the main output is lightly loaded.

The LTC3557/LTC3557-1 is a highly integrated power management and battery charger IC for single cell Li-Ion/ Polymer battery applications. It includes a PowerPathTM manager with automatic load prioritization, a battery charger, an ideal diode and numerous internal protection features. Designed specifically for USB applications, the LTC3557/LTC3557-1 power manager automatically limits input current to a maximum of either 100mA or 500mA for USB applications or 1A for wall adapter powered applications. Battery charge current is automatically reduced such that the sum of the load current and the charge current does not exceed the programmed input current limit. The LTC3557/LTC3557-1 also includes three adjustable synchronous step-down switching regulators and a high voltage buck regulator output controller with Bat-Track that allows efficient charging from supplies as high as 38V. The LTC3557/LTC3557-1 is available in a low profile 4mm × 4mm × 0.75mm 28-pin QFN package.

The LTC®3441 is a high efficiency, fixed frequency, buck-boost DC/DC converter that operates efficiently from input voltages above, below or equal to the output voltage. The topology incorporated in the IC provides a continuous trans- fer function through all operating modes, making the prod- uct ideal for single lithium ion or multicell applications where the output voltage is within the battery voltage range. The device includes two 0.10Ω N-channel MOSFET switches and two 0.11Ω P-channel switches. External Schottky diodes are optional, and can be used for a moderate efficiency improvement. The operating frequen- cy is 1MHz, and can be synchronized via external components. The device features a ≤25µA quiescent current, which allows true output disconnect in standby mode. The device is available in a thermally enhanced 12-lead (4mm × 3mm) DFN package.

LTC3862 is a two phase constant frequency, current mode boost and SEPIC controller that drives N-channel power MOSFETs. It has adjustable slope compensation gain to optimize the current loop gain and improve noise immunity. The operating frequency can be set with an external resistor over a 75kHz to 500kHz range and can be synchronized to an external clock using the internal PLL. Multi-phase operation is possible using the SYNC input, the CLKOUT output and the PHASEMODE control pin allowing 2-, 3-, 4-, 6- or 12-phase operation. Other features include an internal 5V LDO with undervoltage lockout protection for the gate drivers, a precision RUN pin threshold with programmable hysteresis, soft-start and programmable leading edge blanking and maximum duty cycle.

LTC3830/LTC3830-1 3830fa high power step-down synchronous DC/DC controllers for low voltage operation

The LT4220 is a dual voltage hot swap controller from Linear Technology Corporation that supports positive and negative two-way power, has overcurrent limiting, power tracking, and switch tube shutdown functions, and is used in RAID systems, –5.2V ECL power supplies, industrial controls, and other scenarios.

The LTC3802 is a dual switching regulator controller optimized for high efficiency step-down conversion from input voltages between 3V to 30V. The controller uses a leading edge modulation scheme to allow extremely low duty cycle operation. The constant frequency voltage mode controller allows a phase-lockable frequency between 330kHz and 750kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages 180° out-of-phase.