LT5571

www.DataSheet4U.com FEATURES ■ ■ ■ ■ LT5571 620MHz – 1100MHz High Linearity Direct Quadrature Modulator DESCRIPTION The LT®5571 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 singleended 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. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ ■ ■ ■ ■ ■ ■ Direct Conversion from Baseband to RF High Output: –4.2dB Conversion Gain High OIP3: 21.7dBm at 900MHz Low Output Noise Floor at 20MHz Offset: No RF: –159dBm/Hz POUT = 4dBm: –153.3dBm/Hz Low Carrier Leakage: –42dBm at 900MH...