Linear Technology announces the LTC5585, an ultrawide bandwidth direct conversion I/Q demodulator that demonstrates input third-order intercept point (IIP3) of 25.7dBm and IIP2 of 60dBm at 1.95GHz. The device is capable of baseband output demodulation bandwidth of over 530MHz to support new generation wideband LTE multimode receivers’ and digital pre-distortion (DPD) receivers’ bandwidth requirements. The I/Q demodulator operates over the 700MHz to 3GHz frequency range of all cellular base station frequency bands. This device has two built-in calibration features. One is advanced circuitry that enables the system designer to optimize the receiver’s IIP2 performance from 60dBm to a 80dBm or higher. The other is on-chip circuitry to null out the DC offset voltages at the I and Q outputs. The LTC5585 delivers P1dB of +16dBm.
In direct conversion receiver applications, the LTC5585 offers low I/Q amplitude and phase mismatch. The amplitude mismatch is typically 0.05dB, while the phase error is typically 0.7 degree, both measured at 1.95GHz. This combination produces a receiver image rejection capability of 43dB. Its bandwidth capability makes the LTC5585 suitable for multimode LTE, W-CDMA and TD-SCDMA base stations DPD receivers as well as for main receiver applications. Particularly for DPD, these latest generation base stations push demodulation bandwidth of over 300MHz. The LTC5585 can be configured to meet these bandwidth challenges. Other applications include military receivers, broadband communications, point-to-point microwave data links, image reject receivers and long-range RFID readers.
The LTC5585 has an on-chip RF transformer to reduce external components, providing a compact solution with its 24-lead 4mm x 4mm QFN package. The device is specified for case operating temperature from -40°C to 105°C.
The LTC5585 is powered from a single 5V supply, drawing a supply current of 200mA. A digital input enables or disables the chip. When disabled, the IC draws typically 11µA of leakage current. The demodulator’s turn-on time of 200ns and turn-off time of 800ns enable its use in burst mode receivers. The LTC5585 is priced starting at $5.98 each in 1,000-pieces quantities. Production quantities are now immediately available.
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