Analog Devices Inc./Maxim Integrated

The LTC1666/LTC1667/LTC1668 are 12-/14-/16-bit, 50Msps differential current output DACs implemented on a high performance BiCMOS process with laser trimmed, thin-film resistors. The combination of a novel current-steering architecture and a high performance process produces DACs with exceptional AC and DC performance. The LTC1668 is the first 16-bit DAC in the marketplace to exhibit an SFDR (spurious free dynamic range) of 87dB for an output signal frequency of 1MHz.Operating from ±5V supplies, the LTC1666/LTC1667/LTC1668 can be configured to provide full-scale output currents up to 10mA. The differential current outputs of the DACs allow single-ended or true differential operation. The –1V to 1V output compliance of the LTC1666/LTC1667/LTC1668 allows the outputs to be connected directly to external resistors to produce a differential output voltage without degrading the converter’s linearity. Alternatively, the outputs can be connected to the summing junction of a high speed operational amplifier, or to a transformer.The LTC1666/LTC1667/LTC1668 are pin compatible and are available in a 28-pin SSOP and are fully specified over the industrial temperature range.ApplicationsCellular Base StationsMulticarrier Base StationsWireless CommunicationDirect Digital Synthesis (DDS)xDSL ModemsArbitrary Waveform GenerationAutomated Test EquipmentInstrumentation

The LTC1669 is a 10-bit voltage output DAC with true buffered rail-to-rail output voltage capability. It operates from a single supply with a range of 2.7V to 5.5V. The reference for the DAC is selectable between the supply voltage or an internal bandgap reference. Selecting the internal bandgap reference will set the full-scale output voltage range to 2.5V. Selecting the supply as the reference sets the output voltage range to the supply voltage.The part features a simple 2-wire serial interface compatible with I2C that allows communication between many devices. The internal data registers are double buffered to allow for simultaneous update of several devices at once. The DAC can be put in low current power-down mode for use in power conscious systems.Power-on reset ensures the DAC output is at 0V when power is initially applied, and all internal registers are cleared. The LTC1669 is pin-for-pin compatible with the LTC1663.For SMBus-compatible designs, please refer to the LTC1663.ApplicationsDigital CalibrationOffset/Gain AdjustmentIndustrial Process ControlAutomatic Test EquipmentArbitrary Function GeneratorsBattery-Powered Data Conversion Products

The LTC1682/LTC1682-3.3/LTC1682-5 are doubler charge pumps with an internal low noise, low dropout (LDO) linear regulator. These parts are designed to provide a low noise boosted supply voltage for powering noise sensitive devices such as high frequency VCOs in wireless applications.An internal doubler charge pump converts a 1.8V to 4.4V input to a boosted output, while the internal LDO regulator converts the boosted voltage to a low noise regulated output. The adjustable version allows the user to set VOUTvia external resistors connected to FB. The regulator is capable of supplying up to 50mA of output current. Shutdown reduces the supply current to < 5µA, removes the load from VINby disabling the regulator and discharges VOUTto ground through a 100Ω switch.The LTC1682 LDO regulator is stable with only 2µF on the output. Small ceramic capacitors can be used, reducing PC board area.The LTC1682/LTC1682-3.3/LTC1682-5 are short-circuit and over temperature protected. The parts are available in 8-pin MSOP and SO packages.ApplicationsVCO Power Supplies in Cellular Phones2-Way PagersWireless PCMCIA CardsPortable Medical InstrumentsLow Power Data AcquisitionRemote Transmitters

The LTC1688/LTC1689 are ultrahigh speed, differential bus/line drivers that can operate at data rates up to 100Mbps. Propagation delay is guaranteed at 8ns ±4ns over the full operating temperature range. These devices operate over the full RS485 common mode range (–7V to 12V), and also meet RS422 requirements.The driver outputs are Hot Swap capable, maintaining backplane data integrity during board insertion and removal. The drivers feature three-state outputs, maintaining high impedance over the entire common mode range (–7V to 12V). Outputs also remain high impedance during power-up and with the power off. A short-circuit feature detects bus contention and substantially reduces driver output current. Thermal shutdown circuitry protects the parts from excessive power dissipation.The LTC1688 allows all four drivers to be enabled together, while the LTC1689 allows two drivers at a time to be enabled.The LTC1688/LTC1689 operate from a single 5V or 3V supply and draw only 9mA of supply current.ApplicationsHigh Speed RS485 Twisted-Pair DriversHigh Speed Backplane DriversComplementary Clock DriversSTS-1/OC-1 Data DriversSCSI Drivers

The LTC1693-5 drives power P-channel MOSFETs at high speed. The 1.5A peak output current reduces switching losses in MOSFETs with high gate capacitance.The LTC1693-5 is a single driver with an output polarity select pin. The MOSFET driver offers VCCindependent CMOS input thresholds with 1.2V of typical hysteresis. It can level-shift the input logic signal up or down to the rail-to-rail VCCdrive for the external MOSFET.The LTC1693-5 contains an undervoltage lockout circuit and a thermal shutdown circuit that disables the external P-channel MOSFET gate drive if activated.The LTC1693-5 comes in an 8-lead MSOP package.ApplicationsPower SuppliesHigh Side DriversMotor/Relay ControlLine DriversBattery Chargers