The MAX2150 is a complete wideband direct upconversion quadrature modulator IC incorporating a 28-bit sigma-delta fractional-N synthesizer. The device is targeted for applications in the 700MHz to 2300MHz frequency range. The super-high-resolution sigma-delta fractional-N synthesizer is capable of better than 50mHz resolution when used with a 10MHz reference. Other features: fully differential I/Q modulation inputs, an internal LO buffer, and a 50 wideband output driver amplifier. A standard 3-wire interface is provided for synthesizer programming and overall device configuration. An onchip low-noise crystal oscillator amplifier is also included and can be configured as a buffer when an external reference oscillator is used.