GENERAL DESCRIPTION
The SX1781 is a high-performance low phase noise integer-N frequency synthesizer for wireless communications applications. The circuit embeds a fully integrated PLL (including VCO tank and loop filter), complementary output buffers The divider and power-down settings are programmable via an SPI interface. A Lock Detector pin linked to a squelch function have been designed to ease the software development.

FEATURES
◆ Frequency range:1200 to 1400 MHz
◆ Frequency step: 250 kHz min.
◆ Phase noise: -85 dBc/Hz @ 10 kHz offset
◆ Reference spurs: -67 dBc
◆ Hopping time: 350 µs max.
◆ Operating voltage: 3.0 - 3.6V
◆ Programmable Output Power: up to +5 dBm
◆ Integrated VCO and loop filter
◆ SPI-bus interface
◆ Lock Detect output and squelch
◆ Ultra-low power sleep mode
◆ Complementary RF outputs
◆ Temperature range: -40 to +85°C
◆ 4 x 4 mm MLPQ16 package
◆ Pb-free and RoHS compliant