IDT82V3002APV IDT, Integrated Device Technology Inc, IDT82V3002APV Datasheet - Page 10

• Manufacturer Part Number: IDT82V3002APV
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of IDT82V3002APV

• Function: Wan PLL
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Package Type: SSOP
• Pin Count: 56
• Mounting: Surface Mount
• Lead Free Status / Rohs Status: Not Compliant

3
providing timing (clock) and synchronization (framing) signals to
interface circuits for T1 and E1 Primary Rate Digital Transmission links.
See
3.1
As shown in
enable/disable the TIE Control Block and control the operation mode of
the DPLL Block based on MODE_sel0 and MODE_sel1, IN_sel, TIE_en
pins and the result of the Invalid Input Signal Detection.
Holdover and Freerun. The mode selection pins, MODE_sel1 and
MODE_sel0, select the operation mode. See
Table - 2 Operating Modes and Status
FUNCTIONAL DESCRIPTION
IDT82V3002A
MODE_sel1
The IDT82V3002A is a WAN PLL with dual reference inputs,
The State Control Circuit is an important part of the IDT82V3002A.
The IDT82V3002A has three possible modes of operation: Normal,
Signal Detection
Figure -
Output of the
Invalid Input
0
1. The detail is described in the following sections.
FUNCTIONAL DESCRIPTION
STATE CONTROL CIRCUIT
Figure -
Figure - 3 State Control Block
IN_sel
MODE_sel0
3, the State Control Circuit outputs signals to
Enable/Disable
0
TIE Block
TIE_en
State Control Circuit
MODE_sel1
Mode Control
DPLL Block
Table -
Normal
MODE_sel0
Mode
2.
F8o
10
Table - 2 Operating Modes and Status
synchronously on the rising edge of F8o. Three operating modes,
Normal (S1), Holdover (S3) and Freerun (S0), can be switched from one
to another by changing the MODE_sel0 and MODE_sel1 logic levels.
are triggered by the Invalid Input Reference Detection Circuit and
irrelative to the logic levels on MODE_sel0 and MODE_sel1 pins. That
is, at the stage of S1, the operating mode will be changed automatically
from Normal (S1) to Auto-Holdover (S2) if an invalid input reference is
detected (input reference is out of the capture range). At the stage of S2,
if a transient on the IN_sel pin is detected, the device will change to the
Short Time Holdover Mode (S4) with the TIE Control Block disabled;
otherwise, the device will be changed back to Normal (S1) automatically
if the input reference becomes valid. Refer to
Detection"
(S4) is determined by whether there is a transient on the IN_sel pin. If
the input reference is switched from one to the other, a transient voltage
will occur at the In_sel pin, which makes the device change from Normal
(S1) to Short Time Holdover (S4) automatically. See
Switch"
control block will be disabled automatically as shown in
except the changes from Holdover (S3), Auto-Holdover (S2), or Short
Time Holdover (S4) to Normal (S1).
MODE_sel1
Figure - 4
The mode changes between Normal (S1) and Auto-Holdover (S2)
The mode changes between Normal (S1) and Short Time Holdover
When the operating mode is changed from one to another, the TIE
0
1
1
for details.
for more information.
shows the state control diagram. All state changes occur
WAN PLL WITH DUAL REFERENCE INPUT
MODE_sel0
1
0
1
Reserved
Holdover
"Invalid Input Signal
Freerun
October 15, 2008
Mode
"Reference Input
Figure -
4,