Analog Devices Inc./Maxim Integrated

The LT5570 is a 40MHz to 2.7GHz monolithic Logarithmic Mean-Squared RF power detector. It is capable of RMS measurement of an AC signal with wide dynamic range, from –52dBm to 13dBm depending on frequency. The power of the AC signal in an equivalent decibel-scaled value is precisely converted into DC voltage on a linear scale, independent of the crest factor of the waveforms. The LT5570 is suitable for precision RF power measurement and level control for a wide variety of RF standards, including CDMA, W-CDMA, CDMA2000, TD-SCDMA and WiMAX. The DC output is buffered with a low output impedance amplifier capable of driving a high capacitance load.ApplicationsRMS Power MeasurementRF Power ControlReceive and Transmit Gain ControlW-CDMA, CDMA2000, TD-SCDMA, WiMAXRF Instrumentation

The LT5571 is a direct I/Q modulator designed for high performance wireless applications, including wireless infrastructure. It allows direct modulation of an RF signal using differential baseband I and Q signals. It supports RFID, GSM, EDGE, CDMA, CDMA2000, and other systems. It may also be configured as an image reject upconverting mixer by applying 90° phase-shifted signals to the I and Q inputs. The high impedance I/Q baseband inputs consist of voltage-to-current converters that in turn drive double-balanced mixers. The outputs of these mixers are summed and applied to an on-chip RF transformer, which converts the differential mixer signals to a 50Ω single-ended output. The four balanced I and Q baseband input ports are intended for DC-coupling from a source with a common-mode voltage at about 0.5V. The LO path consists of an LO buffer with single-ended input, and precision quadrature generators that produce the LO drive for the mixers. The supply voltage range is 4.5V to 5.25V.ApplicationsRFID InterrogatorsGSM, CDMA, CDMA2000 TransmittersPoint-to-Point Wireless Infrastructure TxImage Reject Up-Converters for Cellular BandsLow-Noise Variable Phase-Shifter for 620MHz to 1100MHz Local Oscillator Signals

The LT5575 is an 800MHz to 2.7GHz direct conversion quadrature demodulator optimized for high linearity receiver applications. It is suitable for communications receivers where an RF signal is directly converted into I and Q baseband signals with bandwidth up to 490MHz. The LT5575 incorporates balanced I and Q mixers, LO buffer amplifi ers and a precision, high frequency quadrature phase shifter. The integrated on-chip broadband transformers provide 50Ω single-ended interfaces at the RF and LO inputs. Only a few external capacitors are needed for its application in an RF receiver system.The high linearity of the LT5575 provides excellent spurfree dynamic range for the receiver. This direct conversion demodulator can eliminate the need for intermediate frequency (IF) signal processing, as well as the corresponding requirements for image filtering and IF filtering. Channel filtering can be performed directly at the outputs of the I and Q channels. These outputs can interface directly to channel-select filters (LPFs) or to baseband amplifiers.ApplicationsCellular/PCS/UMTS InfrastructureRFID ReaderHigh Linearity Direct Conversion I/Q Receiver

The LT5578 mixer is a high performance upconverting mixer optimized for frequencies in the 0.4GHz to 2.7GHz range. The single-ended LO input and RF output ports simplify board layout and reduce system cost. The mixer needs only –1dBm of LO power and the balanced design results in low LO signal leakage to the RF output. At 1.95GHz operation, the LT5578 provides conversion gain of –0.7dB, high OIP3 of 24.3dBm and a low noise floor of –158dBm/Hz at a –5dBm RF output signal level.The LT5578 offers a high performance alternative to passive mixers. Unlike passive mixers, which have conversion loss and require high LO drive levels, the LT5578 delivers conversion gain at significantly lower LO input levels and is less sensitive to LO power level variations. The lower LO drive level requirements, combined with the excellent LO leakage performance, translate into lower LO signal contamination of the output signal.ApplicationsGSM 900PCS/1800PCS and W-CDMA InfrastructureLTE and WiMAX BasestationsWireless RepeatersPublic Safety Radios

The LT5579 mixer is a high performance upconverting mixer optimized for frequencies in the 1.5GHz to 3.8GHz range. The single-ended LO input and RF output ports simplify board layout and reduce system cost. The mixer needs only –1dBm of LO power and the balanced design results in low LO signal leakage to the RF output. At 2.6GHz operation, the LT5579 provides high conversion gain of 1.3dB, high OIP3 of +26dBm and a low noise floor of –157.5dBm/Hz at a –5dBm RF output signal level.The LT5579 offers a high performance alternative to passive mixers. Unlike passive mixers, which have conversion loss and require high LO drive levels, the LT5579 delivers conversion gain at significantly lower LO input levels and is less sensitive to LO power level variations. The lower LO drive level requirements, combined with the excellent LO leakage performance, translate into lower LO signal contamination of the output signal.ApplicationsGSM/EDGE, W-CDMA, UMTS, LTE and TD-SCDMA Basestations2.6GHz and 3.5GHz WiMAX Basestations2.4GHz ISM Band TransmittersHigh Performance Transmitters

The LT5581 is a 10MHz to 6GHz, low power monolithic precision RMS power detector. The RMS detector uses a proprietary technique to accurately measure the RF power from –34dBm to +6dBm (at 2.14GHz) of modulated signals with a crest factor as high as 12dB. It outputs a DC voltage in linear scale proportional to an RF input signal power in dBm. The LT5581 is suitable for precision power measurement and control for a wide variety of RF standards, including GSM/EDGE, CDMA, CDMA2000, W-CDMA, TD-SCDMA, UMTS, LTE and WiMAX, etc. The final DC output is connected in series with an on-chip 300Ω resistor, which enables further filtering of the output modulation ripple with just a single off-chip capacitor.ApplicationsGSM/EDGE, CMDA, CDMA2000, W-CDMA, LTE, WiMAX RF Power ControlPico-Cells, Femto-Cells RF Power ControlWireless RepeatersCATV/DVB TransmittersMIMO Wireless Access PointsPortable RMS Power Measurement Instrumentation

OBSOLETE PRODUCT Data Sheet For Reference OnlyThe LT580/LT581 are bandgap voltage references utilizing thin film technology and a greatly improved curvature correction technique. Wafer level trimming of both reference and output voltage combines to produce units with high yields to very low TC and tight initial tolerance of output voltage.The LT580/LT581 can both sink and source up to 10mA and can be used in either the series or shunt mode. This allows the reference to be used for both positive and negative output voltages without external components. Minimum input-output voltage is less than 1V in the series mode, providing improved tolerance of low line conditions.For voltage references with improved specifications, please set the LT1019, LT1021, and LT1031 data sheets.ApplicationsA to D and D to A ConvertersPrecision RegulatorsConstant Current SourcesV to F ConvertersBridge Excitation