AD9522-5BCPZ Analog Devices Inc, AD9522-5BCPZ Datasheet - Page 29

• Manufacturer Part Number: AD9522-5BCPZ
• Description: 12- Channel Clock Generator With Integra
• Manufacturer: Analog Devices Inc
• Type: Clock Generator, Fanout Distributionr

Specifications of AD9522-5BCPZ

• 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: 2.4GHz
• 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: 800MHz
• Ic Interface Type: I2C, SPI
• Frequency: 2.4GHz
• No. Of Outputs: 12
• No. Of Multipliers / Dividers: 4
• Supply Voltage Range: 3.135V To 3.465V
• Digital Ic Case Style: LFCSP
• No. Of Pins: 64
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Phase-Locked Loop (PLL)
The AD9522 includes on-chip PLL blocks that can be used with
an external VCO or VCXO to create a complete phase-locked
loop. The PLL requires an external loop filter, which usually
consists of a small number of capacitors and resistors. The
configuration and components of the loop filter help to
establish the loop bandwidth and stability of the PLL.
The AD9522 PLL is useful for generating clock frequencies
from a supplied reference frequency. This includes conversion
of reference frequencies to much higher frequencies for subsequent
division and distribution. In addition, the PLL can be used to
clean up jitter and phase noise on a noisy reference. The exact
choice of PLL parameters and loop dynamics is application specific.
The flexibility and depth of the AD9522 PLL allow the part to
be tailored to function in many different applications and signal
environments.
Configuration of the PLL
Configuration of the PLL is accomplished by programming
the various settings for the R divider, N divider, PFD polarity,
and charge pump current. The combination of these settings
determines the PLL loop bandwidth. These are managed through
programmable register settings (see Table 43 and Table 47) and
by the design of the external loop filter.
Successful PLL operation and satisfactory PLL loop performance
are highly dependent on proper configuration of the PLL
settings, and the design of the external loop filter is crucial to
the proper operation of the PLL.
OPTIONAL
REFIN
REFIN
CLK
CLK
REF1
REF2
BUF
AMP
SWITCHOVER
STATUS
REFERENCE
REF_SEL
STATUS
VS
PRESCALER
ZERO DELAY BLOCK
2, 3, 4, 5, OR 6
P, P + 1
DIVIDE BY 1,
1
GND
0
N DIVIDER
STATUS
Figure 28. PLL Functional Block Diagram
COUNTERS
DISTRIBUTION
REFERENCE
A/B
Rev. 0 | Page 29 of 76
RSET
FROM CHANNEL
PROGRAMMABLE
DIVIDER 0
REFMON
ADIsimCLK™ is a free program that can help with the design
and exploration of the capabilities and features of the AD9522,
including the design of the PLL loop filter. The AD9516 model
found in ADIsimCLK Version 1.2 can also be used for modeling
the AD9522 loop filter. It is available at www.analog.com/clocks.
Phase Frequency Detector (PFD)
The PFD takes inputs from the R divider and the N divider and
produces an output proportional to the phase and frequency
difference between them. The PFD includes a programmable
delay element that controls the width of the antibacklash pulse.
This pulse ensures that there is no dead zone in the PFD
transfer function and minimizes phase noise and reference
spurs. The antibacklash pulse width is set by 0x017[1:0].
An important limit to keep in mind is the maximum frequency
allowed into the PFD. The maximum input frequency into the
PFD is a function of the antibacklash pulse setting, as specified
in the phase/frequency detector (PFD) parameter in Table 2.
Charge Pump (CP)
The charge pump is controlled by the PFD. The PFD monitors
the phase and frequency relationship between its two inputs and
tells the CP to pump up or pump down to charge or discharge the
integrating node (part of the loop filter). The integrated and
filtered CP current is transformed into a voltage that drives the
tuning node of the external VCO to move the VCO frequency
up or down. The CP can be set (0x010[3:2]) for high impedance
(allows holdover operation), for normal operation (attempts to
lock the PLL loop), for pump-up, or for pump-down (test modes).
The CP current is programmable in eight steps from (nominally)
0.6 mA to 4.8 mA. The exact value of the CP current LSB is set
by the CPRSET resistor, which is nominally 5.1 kΩ.
N DELAY
FREQUENCY
DETECTOR
DETECT
PHASE
LOCK
CPRSET VCP
CHARGE
PUMP
HOLD
AD9522-5
LD
CP
STATUS