82V3002PVG8 IDT, Integrated Device Technology Inc, 82V3002PVG8 Datasheet - Page 7

• Manufacturer Part Number: 82V3002PVG8
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of 82V3002PVG8

• Lead Free Status / Rohs Status: Compliant

IDT82V3002 WAN PLL WITH DUAL REFERENCE INPUTS
automatically enables the Holdover Mode (Auto-Holdover) when the
frequency of the incoming signal is out of the capture range (See AC
Electrical Characteristics - Performance). This includes a complete loss of
input reference, or a large frequency shift in the input reference. When the
input reference returns to normal, the DPLL returns to Normal Mode with
the output signal locked to the input reference signal. The holdover output
signal in the IDT82V3002 is based on the input reference signal 30 ms to
60 ms prior to entering the Holdover Mode. The amount of phase drift
while in holdover is negligible because the Holdover Mode is very accurate
(e.g., 0.025 ppm). Consequently, the phase delay between the input and
output after switching back to Normal Mode is preserved.
Feedback
TIE_en
signal
IN_sel
Fref1
Fref0
Circuit
Select
Time = 0.00 s
Time = 0.25 s
Time = 0.50 s
Time = 0.75 s
Time = 1.0 s
Time = 1.25 s
Time = 1.50 s
Time = 1.75 s
Figure 4. Reference Switch with TIE Control Block Enabled
Ref1
Ref2
Fref
Figure 3. TIE Control Circuit Diagram
Measure
Circuit
Step Generation
7
TIE CONTROL BLOCK
the other reference or the one generated by the storage techniques
instead. But when switching the reference, a step change in phase on the
input reference will occur. And a step change in phase at the input of the
DPLL would lead to unacceptable phase changes in the output signals. The
TIE control block, when enabled, prevents a step change in phase on the
input reference signals from causing a step change in phase at the output
of the DPLL block. Figure 3 shows the TIE Control Block diagram.
enable logic generated by the State Control Circuit), it will work under the
control of the Step Generation circuit.
If the current reference is badly damaged or lost, it is necessary to use
When the TIE Control Block is enabled (by the TIE_en pin or TIE auto-
125 s
Storage
Circuit
TCLR
Output Clock
Input Clock
INDUSTRIAL TEMPERATURE RANGE
Trigger
Circuit
Reference
Virtual
Signal