The LTC®6945 is a high performance, low noise, 6GHz phaselocked loop (PLL), including a reference divider, phasefrequency detector (PFD) with phase-lock indicator, charge pump, integer feedback divider and VCO output divider. The part features a buffered, programmable VCO output divider with a range of 1 through 6. The differential, low noise output buffer has user-programmable output power ranging from -6dBm to 3dBm, and may be muted through either a digital input pin or software. The low noise reference buffer outputs a typical 0dBm square wave directly into a 50O impedance from 10MHz to 250MHz, or may be disabled through software. The ultralow noise charge pump contains selectable high and low voltage clamps useful for VCO monitoring, and also may be set to provide a V+/2 bias. All device settings are controlled through a SPI-compatible serial port.
