DESCRIPTION
The LT®5568 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 PHS, GSM, EDGE, TD-SCDMA, CDMA, CDMA2000, WCDMA, and other systems. It may also be confi gured as an image reject upconverting mixer, by applying 90° phase-shifted signals to the I and Q inputs. The I/Q baseband inputs consist of voltage-to-current converters that in turn drive double-balanced mixers.

FEATURES
■ Frequency Range: 700MHz to 1050MHz
■ High OIP3: +22.9dBm at 850MHz
■ Low Output Noise Floor at 5MHz Offset:
   No RF: –160.3dBm/Hz
   POUT = 4dBm: –154dBm/Hz
■ 3-Ch CDMA2000 ACPR: –71.4dBc at 850MHz
■ Integrated LO Buffer and LO Quadrature Phase Generator
■ 50Ω AC-Coupled Single-Ended LO and RF Ports
■ 50Ω DC Interface to Baseband Inputs
■ Low Carrier Leakage: –43dBm at 850MHz
■ High Image Rejection: –46dBc at 850MHz
■ 16-Lead 4mm × 4mm QFN Package

APPLICATIONS
■ Infrastructure Tx for Cellular Bands
■ Image Reject Up-Converters for Cellular Bands
■ Low-Noise Variable Phase-Shifter for 700MHz to 1050MHz Local Oscillator Signals
■ RFID Reader