LT5517 Datasheet

• RF Input Frequency Range: 40MHz to 900MHz
• High IIP3: 21dBm at 800MHz
• High IIP2: 58dBm at 800MHz
• I/Q Gain Mismatch: 0.3dB Max
• I/Q Phase Mismatch: 0.7°
• Noise Figure: 12.4dB at 800MHz
• Conversion Gain: 3.3dB at 800MHz
• Baseband Bandwidth: 130MHz
• Single Ended, 50Ω Matched 2XLO Input
• Shutdown Mode
• 16-Lead QFN (4mm × 4mm) Package with Exposed Pad

• Wireless Infrastructure
• High Linearity Direct Conversion I/Q Receiver
• High Linearity I/Q Demodulator

The LT5517 is a 40MHz to 900MHz quadrature demodulator optimized for high linearity receiver applications where high dynamic range is important. It is suitable for communications receivers where an RF or IF signal is directly converted into I and Q baseband signals with a bandwidth up to 130MHz. The LT5517 incorporates balanced I and Q mixers, LO buffer amplifiers and a precision, broadband quadrature generator derived from an on-chip divide-by-two circuit.

The superior linearity and low noise performance of the LT5517 is achieved across its full frequency range. A well-balanced divide-by-two circuit generates precision quadrature LO carriers to drive the I mixer and the Q mixer. Consequently, the outputs of the I-channel and the Q-channel are well matched in amplitude, and their phases are 90° apart. The LT5517 also provides excellent 50Ω impedance matching at the 2XLO port across its entire frequency range.