REVISION D 5/26/16
84320-01 DATA SHEET
9 780MHZ, CRYSTAL-TO-3.3V DIFFERENTIAL
LVPECL FREQUENCY SYNTHESIZER
APPLICATION INFORMATION
As in any high speed analog circuitry, the power supply
pins are vulnerable to random noise. The 84320-01 pro-
vides separate power supplies to isolate any high switching
noise from the outputs to the internal PLL. V
CC
, V
CCA
, and
V
CCO
should be individually connected to the power supply
plane through vias, and bypass capacitors should be
used for each pin. To achieve optimum jitter performance,
power supply isolation is required. Figure 2 illustrates how
a 24Ω resistor along with a 10μF and a .01μF bypass
capacitor should be connected to each V
CCA
pin. The 24Ω resistor
can also be replaced by a ferrite bead.
POWER SUPPLY FILTERING TECHNIQUES
FIGURE 2. POWER SUPPLY FILTERING
24Ω
V
CCA
10μF
.01μF
3.3V
.01μF
V
CC
INPUTS:
CRYSTAL INPUTS
For applications not requiring the use of the crystal oscillator
input, both XTAL_IN and XTAL_OUT can be left fl oating. Though
not required, but for additional protection, a 1kΩ resistor can be
tied from XTAL_IN to ground.
TEST_CLK I
NPUT
For applications not requiring the use of the test clock, it can be
left fl oating. Though not required, but for additional protection, a
1kΩ resistor can be tied from the TEST_CLK to ground.
LVCMOS C
ONTROL PINS
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional
protection. A 1kΩ resistor can be used.
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS
OUTPUTS:
LVPECL OUTPUTS
All unused LVPECL outputs can be left fl oating. We recommend
that there is no trace attached. Both sides of the differential
output pair should either be left fl oating or terminated.
