ADRF670x Series Modulators

By Analog Devices Inc 172

ADRF670x Series Modulators

Analog Devices' ADRF670x provides a quadrature modulator and synthesizer solution within a small 6 mm × 6 mm footprint while requiring minimal external components. The ADRF670x is designed for RF outputs from 400 MHz to 1250 MHz. The low phase noise VCO and high performance quadrature modulator make the ADRF670x suitable for next generation communication systems requiring high signal dynamic range and linearity. The integration of the IQ modulator, PLL, and VCO provides for significant board savings and reduces the BOM and design complexity.

The integrated fractional-N PLL/synthesizer generates a 2× fLO input to the IQ modulator. The phase detector together with an external loop filter is used to control the VCO output. The VCO output is applied to a quadrature divider. To reduce spurious components, a sigma-delta (Σ-Δ) modulator controls the programmable PLL divider.

The IQ modulator has wideband differential I and Q inputs, which support baseband as well as complex IF architectures. The single-ended modulator output is designed to drive a 50 Ω load impedance and can be disabled. The ADRF670x is fabricated using an advanced silicon-germanium BiCMOS process. It is available in a 40-lead, exposed-paddle, Pb-free, 6 mm × 6 mm LFCSP package. Performance is specified from −40°C to +85°C. A lead-free evaluation board is available.

  • IQ modulator with integrated fractional-N PLL
  • Output frequency range: 400 MHz to 1250 MHz
  • Internal LO frequency range: 750 MHz to 1150 MHz
  • Output P1dB: 10.3 dBm at 1100 MHz
  • Output IP3: 30.1 dBm at 1100 MHz
  • Noise floor: −159.4 dBm/Hz at 1100 MHz
  • Baseband bandwidth: 750 MHz (3 dB)
  • SPI serial interface for PLL programming
  • Integrated LDOs and LO buffer
  • Power supply: 5 V/240 mA
  • 40-lead 6 mm × 6 mm LFCSP