Analog Devices Inc./Maxim Integrated

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

The LTC1695 fan speed controller provides all the functions necessary for a power management microprocessor to regulate the speed of a 5V brushless DC fan via a 2-wire SMBus/I²C interface. Fan speed is controlled according to the system’s required temperature profile and permits lower fan power consumption, longer battery run time and lower acoustical generated noise versus systems that only provide simple on-off control for the fan.The LTC1695 incorporates a 180mA low dropout linear regulator, a 2-wire SMBus/I²C interface and a 6-bit DAC. Fan speed is controlled by varying the fan’s terminal voltage through the output voltage of the LTC1695’s linear regulator. The LTC1695’s output voltage is programmed by sending a 6-bit digital code to the LTC1695 DAC via the SMBus. To eliminate fan start-up problems at lower fan voltages, users can enable the LTC1695’s boost start feature that provides the DAC’s full-scale output voltage for 250ms before decreasing to the programmed output voltage.The LTC1695 includes output current limiting and thermal shutdown as well as status monitors that can be read back by the microprocessor during fault conditions. The LTC1695 is available in a 5-lead SOT-23 package.ApplicationsNotebook ComputersSpot CoolingPortable InstrumentsBattery-Powered SystemsDC Motor ControlWhite LED Power SuppliesProgrammable Low Dropout Regulator

The LTC1697 is designed to control a single 1W cold cathode fluorescent lamp (CCFL). An internal PWM dimming system maximizes efficiency and dimming range. Accurate lamp currents can be set with a single external resistor.The LTC1697 includes a synchronous current mode PWM controller with internal 1A MOSFET switches. It contains a 300kHz oscillator, 0.8V reference, and internal current sense. It operates from a 2.8V to 5.5V input voltage. The LTC1697 also has a thermal limit and a shutdown that reduces supply current to <2µA.The LTC1697 is available in the MSOP-10 package.ApplicationsPDAsHandheld ComputersPortable InstrumentsHandheld GPS with Map DisplayHandheld TV/Video Monitor

The LTC1698 is a precision secondary-side forward converter controller that synchronously drives external N-channel MOSFETs. It is designed for use with the LT3781 primary-side synchronous forward converter controller to create a completely isolated power supply. The LT3781 synchronizes the LTC1698 through a small pulse transformer and the LTC1698 drives a feedback optocoupler to close the feedback loop. Output accuracy of ±0.8% and high efficiency over a wide range of load currents are obtained.The LTC1698 provides accurate secondary-side current limit using an external current sense resistor. The input voltage at the MARGIN pin provides ±5% output voltage adjustment. A power good flag and overvoltage input are provided to ensure proper power supply conditions. An auxiliary 3.3V logic supply is included that supplies up to 10mA of output current.Applications48V Input Isolated DC/DC ConvertersIsolated Telecommunication Power SystemsDistributed Power Step-Down ConvertersIndustrial Control SystemsAutomotive and Heavy Equipment

The LTC1699-80, LTC1699-81 and LTC1699-82 are precision (±0.35% max), digitally programmed resistor dividers that comply with Intel 5-bit mobile (LTC1699-80), desktop VRM8.4 (LTC1699-81) and VRM9.0 (LTC1699-82) VID specifications. Each IC can switch the output of a DC/DC converter between two set voltages. A digital input pin, SEL, selects one of two divider settings stored into registers via a 2-wire SMBus interface.The SMBus interface uses Write Word protocol to setup the registers and to turn the DC/DC converters on or off. Read Word protocol is used to verify register contents and to return the On/Off status of the converters. The LTC1699-80, LTC1699-81 and LTC1699-82 incorporate safeguards against errors due to bus conflicts.Three open-drain N-channel outputs (CPU_ON, IO_ON and CLK_ON) are provided to turn DC/DC converter supplies on or off via their RUB/SS inputs. A global control pin, VRON is used to turn the converters on or off simultaneously. An internal timer pulls the PGOOD pin low for 50µs if the divider setting changes or the converters are turned on via the SMBus and the VRON pin.ApplicationsIntel Desktop Pentium®III Power SupplyIntel Mobile Pentium®Power Supply with Intel SpeedStep™TechnologyDesktop AMD Athlon™Power SupplySoftware Programmable Remote Power SupplyPower Supplies with Voltage Margining

The LTC1700 is a current mode synchronous step-up DC/DC controller that drives external N-channel and P-channel power MOSFETs using a constant frequency PWM architecture. Current limiting is provided by sensing the voltage drop across the main MOSFET, eliminating the need of a sense resistor. This No RSENSE™technique helps the LTC1700 maintain high efficiency at heavy loads while Burst Mode operation ensures high efficiency at light loads, thus providing high efficiencies over a wide range of load currents.The LTC1700 operates at a minimum input voltage as low as 0.9V. The device boasts a ±1.5% output voltage accuracy and consumes only 200µA of quiescent current. In shutdown, it only draws 10µA.To prevent inductor current runaway, the duty cycle is limited to 90%. Overvoltage protection is also provided which shuts both the external MOSFETs off when tripped.High constant operating frequency of 530kHz allows the use of small inductors and output capacitors. The LTC1700 can also be synchronized between 400kHz to 750kHz. Burst Mode operation is inhibited when the device is externally clocked or when the SYNC/MODE pin is pulled low to reduce noise and RF interference.ApplicationsCellular TelephonesWireless ModemsRF Communications2.5V to 3.3V, 2.5V to 5V ConvertersBattery-Powered EquipmentTelecom/Network Systems