AD9522-0BCPZ Analog Devices Inc, AD9522-0BCPZ Datasheet - Page 39
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AD9522-0BCPZ
Manufacturer Part Number
AD9522-0BCPZ
Description
12- Channel Clock Generator With Integra
Manufacturer
Analog Devices Inc
Type
Clock Generator, Fanout Distributionr
Datasheet
1.AD9522-0BCPZ-REEL7.pdf
(84 pages)
Specifications of AD9522-0BCPZ
Pll
Yes
Input
CMOS, LVDS, LVPECL
Output
CMOS, LVDS
Number Of Circuits
1
Ratio - Input:output
2:12, 2:24
Differential - Input:output
Yes/Yes
Frequency - Max
2.95GHz
Divider/multiplier
Yes/No
Voltage - Supply
3.135 V ~ 3.465 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
64-LFCSP
Frequency-max
2.8GHz
Operating Temperature (min)
-40C
Operating Temperature Classification
Industrial
Operating Temperature (max)
85C
Rad Hardened
No
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
AD9522-0BCPZ
Manufacturer:
Analog Devices Inc
Quantity:
135
Company:
Part Number:
AD9522-0BCPZ
Manufacturer:
AD
Quantity:
25
Part Number:
AD9522-0BCPZ
Manufacturer:
ADI/亚德诺
Quantity:
20 000
The holdover function senses the logic level of the LD pin as a
condition to enter holdover. The signal at LD can be from the
DLD, ALD, or current source LD (CSDLD) mode. It is possible
to disable the LD comparator (0x01D[3]), which causes the
holdover function to always sense LD as being high. If DLD is
used, it is possible for the DLD signal to chatter while the PLL is
reacquiring lock. The holdover function may retrigger, thereby
preventing the holdover mode from terminating. Use of the
current source lock detect mode is recommended to avoid this
situation (see the Current Source Digital Lock Detect (CSDLD)
section).
HIGH IMPEDANCE
HIGH IMPEDANCE
WHEN DLD WENT
LD PIN == HIGH
CHARGE PUMP
CHARGE PUMP
EDGE AT PFD?
PLL ENABLED
DLD == HIGH
DLD == LOW
REFERENCE
RELEASE
LOW?
WAS
YES
YES
YES
Figure 47. Flowchart of Automatic/Internal Holdover Mode
NO
NO
NO
NO
YES
Rev. 0 | Page 39 of 84
LOOP OUT OF LOCK. DIGITAL LOCK
DETECT SIGNAL GOES LOW WHEN THE
LOOP LEAVES LOCK AS DETERMINED
BY THE PHASE DIFFERENCE AT THE
INPUT OF THE PFD.
ANALOG LOCK DETECT PIN INDICATES
LOCK WAS PREVIOUSLY ACHIEVED.
(0x01D[3] = 1; USE LD PIN VOLTAGE
WITH HOLDOVER.
0x01D[3] = 0; IGNORE LD PIN VOLTAGE,
TREAT LD PIN AS ALWAYS HIGH.)
CHARGE PUMP IS MADE
HIGH IMPEDANCE.
PLL COUNTERS CONTINUE
OPERATING NORMALLY.
CHARGE PUMP REMAINS HIGH
IMPEDANCE UNTIL THE REFERENCE
RETURNS.
TAKE CHARGE PUMP OUT OF
HIGH IMPEDANCE. PLL CAN
NOW RESETTLE.
WAIT FOR DLD TO GO HIGH. THIS TAKES
5 TO 255 CYCLES (PROGRAMMING OF THE DLD
DELAY COUNTER) WITH THE REFERENCE AND
FEEDBACK CLOCKS INSIDE THE LOCK WINDOW AT
THE PFD. THIS ENSURES THAT THE HOLDOVER
FUNCTION WAITS FOR THE PLL TO SETTLE AND LOCK
BEFORE THE HOLDOVER FUNCTION CAN BE
RETRIGGERED.
When in holdover mode, the charge pump stays in a high
impedance state as long as there is no reference clock present.
As in the external holdover mode, the B counter (in the N divider)
is reset synchronously with the charge pump leaving the high
impedance state on the reference path PFD event. This helps
align the edges out of the R and N dividers for faster settling of
the PLL and reduces frequency errors during settling. Because
the prescaler is not reset, this feature works best when the B and
R numbers are close because this results in a smaller phase
difference for the loop to settle out.
AD9522-0