Analog Devices Inc./Maxim Integrated

The LTC1258/LTC1258-2.5/LTC1258-3/LTC1258-4.1/LTC1258-5 are micropower bandgap references that combine high accuracy and low drift with very low supply current and small package size. The combination of ultralow quiescent current and low dropout voltage of only 200mV maximum makes them ideal for battery-powered equipment. The output voltage is set by an external resistor divider for the adjustable LTC1258.This series of references uses curvature compensation to obtain low temperature coefficient and trimmed thin-film resistors to achieve high output accuracy. These references can source up to 10mA and sink up to 2mA, making them ideal for precision regulator applications. They are stable without an output bypass capacitor, but are also stable with capacitance up to 1μF. This feature is important in critical applications where PC board space is a premium and fast settling is demanded.The LTC1258 series references provide power dissipation advantages over shunt references. In addition to supply current, shunt references must also idle the entire load current to operate.The LTC1258 series is available in the 8-pin MSOP and SO packages.ApplicationsBattery-Powered SystemsHandheld InstrumentsPrecision Power SuppliesA/D and D/A Converters

The LTC1261L is a switched-capacitor voltage inverter designed to provide a regulated negative voltage from a single positive supply. The LTC1261L operates from a single 2.7V to 5.25V supply and provides an adjustable output voltage from -1.23V to ±5V. The LTC1261L-4/LTC1261L-4.5 needs a single 4.5V to 5.25V supply and provides a fixed output voltage of -4V to -4.5V respectively. Three external capacitors are required: a 0.1µF flying capacitor and an input and output bypass capacitors. An optional compensation capacitor at ADJ (COMP) can be used to reduce the output voltage ripple.Each version of the LTC1261L will supply up to 20mA output current with guaranteed output regulation of ±3.5%. The LTC1261L includes an open-drain REG output that pulls low when the output is within 5% of the set value. Quiescent current is typically 650µA when operating and 5µA in shutdown.The LTC1261L is available in 8-pin MSOP and SO packages.ApplicationsGaAs FET Bias GeneratorsNegative Supply GeneratorsBattery-Powered SystemsSingle Supply Applications

The LTC1263 is a regulated 12V, 60mA output DC/DC converter. It provides the 12V ±5% output necessary to program double byte-wide flash memories. The output provides 60mA from input voltages as low as 4.75V without using any inductors. Only four external capacitors are required to complete an extremely small, surface mountable circuit. The output can be momentarily shorted to ground without damaging the part.The active high TTL compatible Shutdown pin can be directly connected to a microprocessor. In the shutdown mode, the supply current typically drops to 0.5µA.The LTC1263 is available in an 8-pin SO package.Applications12V Flash Memory Programming SuppliesCompact 12V Op Amp SuppliesBattery-Powered Systems

The LTC1264 consists of four identical, high speed 2nd order switched-capacitor filter building blocks designed for center frequencies up to 250kHz. Each building block, together with three to five resistors, can provide 2nd order functions like lowpass, highpass, bandpass and notch. The center frequency of each 2nd order section is tuned via an external clock. The clock-to-center frequency ratio is internally set to 20:1, but it can be modified via external resistors.The aliasing performance of the LTC1264 is improved by double-sampling each 2nd order section. Input signal frequencies can reach up to twice the clock frequency before any alias products will be detectable.For Q ≤ 5 and for TA< 85°C, the maximum center frequency is 160kHz. For Q ≤ 2, the maximum center frequency is 250kHz. Up to 8th order filters can be realized by cascading all four 2nd order sections.A customized monolithic version of the LTC1264 including internal thin film resistors can be obtained.ApplicationsDigital CommunicationsSpread Spectrum CommunicationsSpectral AnalysisLoran ReceiversInstrumentation

The LTC1264-7 is a clock-tunable monolithic 8th order lowpass filter with linear passband phase and flat group delay. The amplitude response approximates a maximally flat passband and exhibits steeper roll-off than an equivalent 8th order Bessel filter. For instance, at twice the cutoff frequency, the filter attains 28dB attenuation (vs 12dB for Bessel), while at three times the cutoff frequency, the filter attains 55dB attenuation (vs 30dB for Bessel).The cutoff frequency of the LTC1264-7 is tuned via an external TTL or CMOS clock. The clock-to-cutoff frequency ratio of the LTC1264-7 can be set to 25:1 (pin 10 to V+) or 50:1 (pin 10 to V–). When the filter operates at clock-to-cutoff frequency ratio of 25:1, the input is double-sampled to lower the risk of aliasing.The LTC1264-7 is optimized for speed. Depending on the operating conditions, cutoff frequencies between 200kHz and 250kHz can be obtained. (Please refer to the Passband vs Clock Frequency graphs.)The LTC1264-7 is pin-compatible with the LTC1064-X series.ApplicationsData Communication FiltersTime Delay NetworksPhase Matched Filters

The LTC1266 series is a family of synchronous switching regulator controllers featuring automatic Burst Mode™operation to maintain high efficiencies at low output currents. These devices drive external power MOSFETs at switching frequencies up to 400kHz using a constant off-time current mode architecture providing constant ripple current in the inductor. They can drive either an N-channel or a P-channel topside MOSFET.The operating current level is user-programmable via an external current sense resistor. Wide input supply range allows operation from 3.5V to 18V (20V maximum). Constant off-time architecture provides low dropout regulation limited only by the RDS(ON)of the topside MOSFET (when using the P-channel) and the resistance of the inductor and current sense resistor.The LTC1266 series combines synchronous switching for maximum efficiency at high currents with an automatic low current operating mode, called Burst Mode operation, which reduces switching losses. Standby power is reduced to only 1mW at VIN= 5V (at IOUT= 0). Load currents in Burst Mode operation are typically 0mA to 500mA.ApplicationsNotebook and Palmtop ComputersPortable InstrumentsCellular TelephonesDC Power Distribution SystemsGPS Systems