Analog Devices

The LT1784 is a 2.5MHz 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 750µA of quiescent current and has reverse battery protection, drawing negligible current for reverse supply voltages up to 18V.The input range of the LT1784 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 LT1784 can drive loads up to 15mA 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 LT1784 op amp is available in the 5- and 6-lead SOT-23 packages. For applications requiring lower power, refer to the LT1782 and LT1783 data sheets.ApplicationsPortable InstrumentationBattery-Powered SystemsSensor ConditioningSupply Current SensingMUX Amplifiers4mA to 20mA Transmitters

The LT1785/LT1791are half-duplex and full-duplex differential bus transceivers for RS485 and RS422 applications which feature on-chip protection from overvoltage faults on the data transmission lines. Receiver input and driver output pins can withstand voltage faults up to ±60V with respect to ground with no damage to the device. Faults may occur while the transceiver is active, shut down or powered off.Data rates to 250kbaud on networks of up to 128 nodes are supported. Controlled slew rates on the driver outputs control EMI emissions and improve data transmission integrity on improperly terminated lines. Drivers are specified to operate with inexpensive cables as low as 72Ω characteristic impedance.The LT1785A/LT1791A devices have "fail-safe" receiver inputs to guarantee a receiver output high for shorted, open or inactive data lines. On-chip ESD protection eliminates need for external protection devices.The LT1785/LT1785A are available in 8-lead DIP and SO packages and the LT1791/LT1791A in 14-lead DIP and SO packages.ApplicationsIndustrial Control Data NetworksCAN Bus ApplicationsHVAC Controls

The LT1786F is a fixed frequency, current mode, switching regulator that provides the control function for Cold Cathode Fluorescent Lighting (CCFL). The IC includes an efficient high current switch, an oscillator, output drive logic, control circuitry and a micropower 6-bit 100µA full-scale current output DAC. The DAC provides simple "bits-to-lamp-current control" and communicates using the 2-wire SMBus serial interface. The LT1786F acts as an SMBus slave device using one of two selectable SMBus addresses set by the address pin ADR.On Power-up, the DAC output current assumes midrange or zero scale, depending on the logic state of the ADR pin.The entire IC can be shut down through theSMBSUSpin or by setting theSHDNbit = 1 in the SMBus command byte. Digital data for the DAC output current is retained internally and the supply current drops to 40µA for standby operation. The active lowSHDNpin disables the CCFL control circuitry, but keeps the DAC alive. Supply current in this operating mode drops to 150µA.The LT1786F control circuitry operates from a logic supply voltage of 3.3V or 5V. The IC also has a battery supply pin that operates from 4.5V to 30V. The LT1786F draws 6mA typical quiescent current. A 200kHz switching frequency minimizes magnetic component size. Current mode switching techniques with cycle-by-cycle limiting gives high reliability and simple loop frequency compensation. The LT1786F is available in a 16-pin narrow SO package.ApplicationsNotebook and Palmtop ComputersPortable InstrumentsPersonal Digital Assistants

The LT1787 is a complete micropower precision high side current sense amplifier. The LT1787 monitors bidirectional currents via the voltage across an external sense resistor. A current or voltage output indicates the direction and magnitude of the sense current. The LT1787 delivers greater than a 12-bit dynamic range with ultralow 40µV input offset voltage compared to a typical 250mV full-scale input voltage. A fixed gain of 8 is set by onboard precision resistors. Input signal filtering is easily implemented with a capacitor between the FIL–and FIL+pins. The LT1787HV operates from 2.5V to 60V total supply voltage and the LT1787 operates from 2.5V to 36V total supply voltage. Both versions have a PSRR in excess of 120dB. The LT1787/LT1787HV draw only 60µA and are available in 8-lead SO and MSOP packages.ApplicationsBattery MonitoringPower MonitoringPortable PhonesCellular PhonesPortable Test/Measurement SystemsBattery-Operated Systems

The LT1790 is a family of SOT-23 micropower low dropout series references that combine high accuracy and low drift with low power dissipation and small package size. These micropower references use curvature compensation to obtain a low temperature coefficient and trimmed precision thin-film resistors to achieve high output accuracy. In addition, each LT1790 is post-package trimmed to greatly reduce the temperature coefficient and increase the output accuracy. Output accuracy is further assured by excellent line and load regulation. Special care has been taken to minimize thermally induced hysteresis.The LT1790s are ideally suited for battery-operated systems because of their small size, low supply current and reduced dropout voltage. These references provide supply current and power dissipation advantages over shunt references that must idle the entire load current to operate. Since the LT1790 can also sink current, it can operate as a micropower negative voltage reference with the same performance as a positive reference.ApplicationsHandheld InstrumentsNegative Voltage ReferencesIndustrial Control SystemsData Acquisition SystemsBattery-Operated Equipment

TheLT1785/LT1791 are half-duplex and full-duplex differential bus transceivers for RS485 and RS422 applications which feature on-chip protection from overvoltage faults on the data transmission lines. Receiver input and driver output pins can withstand voltage faults up to ±60V with respect to ground with no damage to the device. Faults may occur while the transceiver is active, shut down or powered off.Data rates to 250kbaud on networks of up to 128 nodes are supported. Controlled slew rates on the driver outputs control EMI emissions and improve data transmission integrity on improperly terminated lines. Drivers are specified to operate with inexpensive cables as low as 72Ω characteristic impedance.The LT1785A/LT1791A devices have "fail-safe" receiver inputs to guarantee a receiver output high for shorted, open or inactive data lines. On-chip ESD protection eliminates need for external protection devices.The LT1785/LT1785A are available in 8-lead DIP and SO packages and the LT1791/LT1791A in 14-lead DIP and SO packages.ApplicationsIndustrial Control Data NetworksCAN Bus ApplicationsHVAC Controls

The LT1792 achieves a new standard of excellence in noise performance for a JFET op amp. The 4.2nV/√Hzvoltage noise combined with low current noise and picoampere bias currents make the LT1792 an ideal choice for amplifying low level signals from high impedance capacitive transducers.The LT1792 is unconditionally stable for gains of 1 or more, even with load capacitances up to 1000pF. Other key features are 600µV VOS and a voltage gain of over 4 million. Each individual amplifier is 100% tested for voltage noise, slew rate and gain bandwidth.The design of the LT1792 has been optimized to achieve true precision performance with an industry standard pinout in the SO-8 package. Specifications are also provided for ±5V supplies.ApplicationsPhotocurrent AmplifiersHydrophone AmplifiersHigh Sensitivity Piezoelectric AccelerometersLow Voltage and Current Noise Instrumentation Amplifier Front EndsTwo and Three Op Amp Instrumentation AmplifiersActive Filters

The LT1793 achieves a new standard of excellence in noise performance for a JFET op amp. For the first time low voltage noise (6nV/√Hz) is simultaneously offered with extremely low current noise (0.8fA/√Hz), providing the lowest total noise for high impedance transducer applications. Unlike most JFET op amps, the very low input bias current (3pA typ) is maintained over the entire common mode range which results in an extremely high input resistance (1013Ω). When combined with a very low input capacitance (1.5pF) an extremely high input impedance results, making the LT1793 the first choice for amplifying low level signals from high impedance transducers. The low input capacitance also assures high gain linearity when buffering AC signals from high impedance transducers.The LT1793 is unconditionally stable for gains of 1 or more, even with 1000pF capacitive loads. Other key features are 250µV VOSand a voltage gain over 4 million. Each individual amplifier is 100% tested for voltage noise, slew rate (3.4V/µs) and gain-bandwidth product (4.2MHz).Specifications at ±5V supply operation are also provided. For an even lower voltage noise please see the LT1792 data sheet.ApplicationsPhotocurrent AmplifiersHydrophone AmplifiersHigh Sensitivity Piezoelectric AccelerometersLow Voltage and Current Noise Instrumentation Amplifier Front EndsTwo and Three Op Amp Instrumentation AmplifiersActive Filters

The LT1794 is a 500mA minimum output current, dual op amp with outstanding distortion performance. The amplifiers are gain-of-ten stable, but can be easily compensated for lower gains. The extended output swing allows for lower supply rails to reduce system power. Supply current is set with an external resistor to optimize power dissipation. The LT1794 features balanced, high impedance inputs with low input bias current and input offset voltage. Active termination is easily implemented for further system power reduction. Short-circuit protection and thermal shutdown insure the device’s ruggedness.The outputs drive a 100Ω load to ±11.1V with ±12V supplies, and ±10.9V with a 250mA load. The LT1794, with its increased swing on lower supplies, can be used to upgrade LT1795 line driver applications.The LT1794 is available in the very small, thermally enhanced, 20-lead TSSOP for maximum port density in line driver applications. The 20-lead SW is also available.ApplicationsHigh Density ADSL Central Office Line DriversHigh Efficiency ADSL, HDSL2, G.lite, SHDSL Line DriversBuffersTest Equipment AmplifiersCable Drivers