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HMC702LP6CE

v07.0411

14 GHz 16-BIT FRACTIONAL-N PLL

Autosweep Mode

the autosweep mode is similar to Figure 16 except that once started, triggers are not required. once enabled, (ramp_

repeat_en=1 Reg14h<3> table 30) the autosweep mode initiates the first trigger, steps n times, one step per ref clock

cycle, and then waits for the programmed dwell period and automatically triggers the ramp in the opposite direction.

the sweep process continues alternating sweep directions until disabled. dwell_time (Reg17h table 33) controls the

2-Way Sweeps

if ramp_repeat_en (Reg14h<3> table 30) is cleared, then the ramps are triggered by

a. Writing to ramp_trigg (Reg14h<2> table 30), if bit <2> = 0, or

b. by rising edge ttL signal input on GPo3, if ramp_trig_ext_en is set, and GPo3 is enabled.

all functions are the same in Figure 16 for autosweep or 2-Way triggered sweeps, the only difference is the trigger

source is generated internally for autosweep, and is input via serial port or GPo3 for triggered sweeps. Sweep_busy

will go high at the start of every ramp and stay high until the nth step in the ramp.

Figure 16. 2-Way Sweep Control via Trigger

Triggered 1-Way Sweeps

1-Way sweeps are shown in Figure 17.

Unlike 2-Way sweeps, 1-Way sweeps require that the Vco hop back to the start frequency after the dwell period.

to allow the Vco to settle after the large frequency hop back to the start frequency. Subsequent odd numbered

triggers will start the 1-Way sweep and repeat the process.