Analog Devices

The LT1766/LT1766-5 are 200kHz monolithic buck switching regulators that accept input voltages up to 60V. A high efficiency 1.5A, 0.2Ω switch is included on the die along with all the necessary oscillator, control and logic circuitry. A current mode control architecture delivers 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 25μA and the device can be externally synchronized from 228kHz to 700kHz with logic-level inputs.The LT1766/LT1766-5 are available in a 16-pin fused-lead SSOP package or a TSSOP package with exposed backside for improved thermal performance.ApplicationsHigh Voltage, Industrial and AutomotivePortable ComputersBattery-Powered SystemsBattery ChargersDistributed Power Systems

The LT1767 is a 1.25MHz monolithic buck switching regulator. A high efficiency 1.5A, 0.22Ω 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 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 improves efficiency, especially at lower output currents. Shutdown reduces quiescent current to 6μA. 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 LT1767 is available in an 8-pin MSOP fused lead-frame package and a low thermal resistance exposed pad package. Full cycle-by-cycle current limit and thermal shutdown are provided. High frequency operation allows the reduction of input and output filtering components and permits the use of chip inductors.ApplicationsDSL ModemsPortable ComputersWall AdaptersBattery-Powered SystemsDistributed Power

The LT1768 is designed to control single or multiple cold cathode fluorescent lamp (CCFL) displays. A unique Multimode Dimming scheme* combines both linear and PWM control functions to maximize lamp life, efficiency, and dimming range. Accurate maximum and minimum lamp currents can be easily set. The LT1768 can detect and protect against lamp failures and overvoltage start-up conditions. It is designed to provide maximum flexibility with a minimum number of external components.The LT1768 is a current mode PWM controller with a 1.5A MOSFET driver for high power applications. It contains a 350kHz oscillator, 5V reference, and a current sense comparator with a 100mV threshold. It operates from an 8V to 24V input voltage. The LT1768 also has undervoltage lockout, thermal limit, and a shutdown pin that reduces supply current to 65µA. It is available in a small 16-lead SSOP package.ApplicationsDesktop Flat Panel DisplaysMultiple Lamp DisplaysNotebook LCD DisplaysPoint of Sale Terminal Displays

The LT1769 current mode PWM battery charger is a simple, efficient solution to fast charge modern rechargeable batteries including lithium-ion (Li-Ion), nickel-metal-hydride (NiMH) and nickel-cadmium (NiCd) that require constant-current and/or constant-voltage charging. The internal switch is capable of delivering 2A** DC current (3A peak current). Charge current can be programmed by resistors or a DAC to within 5%. With 0.5% reference voltage accuracy, the LT1769 meets the critical constant-voltage charging requirement for Li-Ion cells.A third control loop is provided to regulate the current drawn from the input AC adapter. This allows simultaneous operation of the equipment and battery charging without overloading the adapter. Charge current is reduced to keep the adapter current below specified levels.The LT1769 can charge batteries ranging from 1V to 20V. Ground sensing of current is not required and the battery’s negative terminal can be tied directly to ground. A saturating switch running at 200kHz gives high charging efficiency and small inductor size. A blocking diode is not required between the chip and the battery because the chip goes into sleep mode and drains only 3µA when the wall adapter is unplugged.ApplicationsChargers for NiCd, NiMH, Lead-Acid, Lithium Rechargeable BatteriesSwitching Regulators with Precision Current Limit

The LT1776 is a wide input range, high efficiency Buck (step-down) switching regulator. The monolithic die includes all oscillator, control and protection circuitry. The part can accept input voltages as high as 60V and contains an output switch rated at 700mA peak current. Current mode control delivers excellent dynamic input supply rejection and short-circuit protection.The LT1776 contains several features to enhance efficiency. The internal control circuitry is normally powered via the VCCpin, thereby minimizing power drawn directly from the VINsupply. The action of the LT1776 switch circuitry is also load dependent. At medium to high loads, the output switch circuitry maintains fast rise time for good efficiency. At light loads, rise time is deliberately reduced to avoid pulse skipping behavior.The available SO-8 package and 200kHz switching frequency allow for minimal PC board area requirements.ApplicationsAutomotive DC/DC ConvertersCellular Phone Battery Charger AccessoriesIEEE 1394 Step-Down Converters

The LT1777 is a Buck (step-down) regulator designed for noise sensitive applications. It contains a dI/dt limiting circuit programmed via a small external inductor in the switching path. Internal circuitry also generates controlled dV/dt ramp rates.The monolithic die includes all oscillator, control and protection circuitry. The part can accept operating input voltages as high as 48V, and contains an output switch rated at 700mA peak current. Current mode control offers excellent dynamic input supply rejection and short-circuit protection. The internal control circuitry is normally powered via the VCCpin, thereby minimizing power drawn directly from the VINsupply (see Applications Information). The fused-lead SO16 package and 100kHz switching frequency allow for minimal PC board area requirements.ApplicationsAutomotive Cellular and GPS ReceiversTelecom Power SuppliesIndustrial Instrument Power Supplies

The LT1780/LT1781 are dual RS232 driver/receiver pairs with integral charge pump to generate RS232 voltage levels from a single 5V supply. Using only 0.1µF external capacitors, these circuits consume only 40mW of power, and can operate to 120kbaud even while driving heavy capacitive loads. New ESD structures on the chip allow the LT1780/LT1781 to survive ±15kV air gap and ±8kV contact ESD tests per IEC 1000-4-2, eliminating the need for costly TransZorbs®on the RS232 line pins. The LT1780/LT1781 are fully compliant with EIA RS232 standards. Driver outputs are protected from overload, and can be shorted to ground or up to ±30V without damage. During SHUTDOWN or power-off conditions, driver and receiver outputs are in a high impedance state, allowing line sharing.The LT1780/LT1781 are direct upgrades to the LT1180A/LT1181A, LT1280A/LT1281A and LT1381 for applications which require the utmost ESD protection.The LT1781 is available in 16-pin DIP,SO and SW packages. The LT1780 is supplied in 18-pin DIP and SW packages for applications which require SHUTDOWN.ApplicationsPortable ComputersBattery-Powered SystemsPower Supply GeneratorTerminalsModems

The LT1780/LT1781 are dual RS232 driver/receiver pairs with integral charge pump to generate RS232 voltage levels from a single 5V supply. Using only 0.1µF external capacitors, these circuits consume only 40mW of power, and can operate to 120kbaud even while driving heavy capacitive loads. New ESD structures on the chip allow the LT1780/LT1781 to survive ±15kV air gap and ±8kV contact ESD tests per IEC 1000-4-2, eliminating the need for costly TransZorbs®on the RS232 line pins. The LT1780/LT1781 are fully compliant with EIA RS232 standards. Driver outputs are protected from overload, and can be shorted to ground or up to ±30V without damage. During SHUTDOWN or power-off conditions, driver and receiver outputs are in a high impedance state, allowing line sharing.The LT1780/LT1781 are direct upgrades to the LT1180A/LT1181A, LT1280A/LT1281A and LT1381 for applications which require the utmost ESD protection.The LT1781 is available in 16-pin DIP,SO and SW packages. The LT1780 is supplied in 18-pin DIP and SW packages for applications which require SHUTDOWN.ApplicationsPortable ComputersBattery-Powered SystemsPower Supply GeneratorTerminalsModems

The LT1782 is a 200kHz op amp available in the small SOT-23 package that operates on all single and split supplies with a total voltage of 2.5V to 18V. The amplifier draws less than 55μA of quiescent current and has reverse battery protection, drawing negligible current for reverse supply voltages up to 18V.The input range of the LT1782 includes ground, and a unique feature of this device is its Over-The-Top™operation capability with either or both of its inputs above the positive rail. The inputs handle 18V both differential and common mode, independent of supply voltage. The input stage incorporates phase reversal protection to prevent false outputs from occurring even when the inputs are 9V below the negative supply.The LT1782 can drive loads up to 18mA and still maintain rail-to-rail capability. A shutdown feature on the 6-lead version can disable the part, making the output high impedance and reducing quiescent current to 5μA. The LT1782 op amp is available in the 5- and 6-lead SOT-23 packages. For applications requiring higher speed, refer to the LT1783.ApplicationsPortable InstrumentationBattery- or Solar-Powered SystemsSensor ConditioningSupply Current SensingBattery MonitoringMUX Amplifiers4mA to 20mA Transmitters

The LT1783 is a 1.25MHz op amp available in the small SOT-23 package that operates on all single and split supplies with a total voltage of 2.5V to 18V. The amplifier draws less than 300µA of quiescent current and has reverse-battery protection, drawing negligible current for reverse supply voltages up to 18V.The input range of the LT1783 includes ground, and a unique feature of this device is its Over-The-Top®operation capabilitity with either or both of its inputs above the positive rail. The inputs handle 18V both differential and common mode, independent of supply voltage. The input stage incorporates phase reversal protection to prevent false outputs from occurring even when the inputs are 9V below the negative supply.The LT1783 can drive loads up to 18mA and still maintain rail-to-rail capability. A shutdown feature on the 6-lead version can disable the part, making the output high impedance and reducing quiescent current to 5µA. The LT1783 op amp is available in the 5- and 6-lead SOT-23 packages. For applications requiring lower power, refer to the LT1782.ApplicationsPortable InstrumentationBattery- or Solar-Powered SystemsSensor ConditioningSupply Current SensingBattery MonitoringMUX Amplifiers4mA to 20mA Transmitters