The MAX2753 is a self-contained voltage-controlled oscillator (VCO) intended for use in 2.4GHz radios that utilize a low-IF or zero-IF architecture. It combines a fully integrated oscillator and output buffer in a miniature 8-pin µMAX® package.
The inductor and varactor elements of the tank are integrated on-chip, greatly simplifying application of the part. The only required external components are a couple of supply bypass capacitors. The MAX2753 provides direct connection to the VCO tuning voltage input and the VCO buffer output. The tuning voltage input range is +0.4V to +2.4V, and the oscillator frequency tuning range is factory adjusted to provide guaranteed limits. The output signal is buffered by an amplifier stage (internally matched to 50Ω ) to provide higher output power and isolate the device from load impedance variations. In addition, the MAX2753 provides differential outputs.
The MAX2753 operates over a +2.7V to +5.5V supply voltage range. Internal regulation of the oscillator supply voltage eliminates the need for an external LDO regulator for the VCO. The MAX2753 also provides a digitally controlled shutdown mode to permit implementation of sophisticated power-supply management. In shutdown, the supply current is reduced to less than 1µA.