GA1085

TriQuint's GA1085 is a configurable clock buffer which generates 11 outputs and operates over a wide range of frequencies-from 24 MHz to 105 MHz. The outputs of GA1085 are available at either 1x and 2x or at 1x and  1/₂ x the reference clock frequency, f_REF. When one of the Group A outputs (Q4Q8) is used as feedback to the PLL, all Group A outputs will be at f_REF  , and all Group B (Q0Q3) and Group C (Q9, Q10) outputs will be at  1/₂ x f_REF  . When one of the Group B outputs is used as feedback to the PLL, all Group A outputs will be at 2x _REF and all Group B and Group C outputs will be at f_REF  . The Shift Select pins select the phase shift (2t, t, +t or +2t) for Group C outputs (Q9, Q10) with respect to REFCLK. The phase shift increment (t) is equivalent to the VCO's period (1/f_VCO).

A very stable internal Phase-Locked Loop (PLL) of GA1085 provides low-jitter operation. This completely self-contained PLL requires no external capacitors or resistors. The PLL's Voltage-Controlled Oscillator (VCO) has a frequency range from 280 MHz to 420 MHz. By feeding back one of the output clocks to FBIN, the PLL continuously maintains frequency and phase synchron-ization between the reference clock (REFCLK) and each of the outputs.

TriQuint's patented output buffer design delivers a very low output-to-output skew of 150 ps (max). The GA1085's symmetrical TTL outputs are capable of sourcing and sinking 30 mA.