AD9516-4BCPZ Analog Devices Inc, AD9516-4BCPZ Datasheet - Page 46

• Manufacturer Part Number: AD9516-4BCPZ
• Description: Clock IC With 1.8GHz On-chip VCO
• Manufacturer: Analog Devices Inc
• Type: Clock Generator, Fanout Distributionr

Specifications of AD9516-4BCPZ

• Pll: Yes
• Input: Clock
• Output: CMOS, LVDS, LVPECL
• Number Of Circuits: 1
• Ratio - Input:output: 1:14
• Differential - Input:output: Yes/Yes
• Frequency - Max: 1.8GHz
• 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: 1.8GHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AD9516-4/PCBZ - BOARD EVAL FOR AD9516-4 1.8GHZ
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD9516-4
Calculating the Fine Delay
The following values and equations are used to calculate the
delay of the delay block.
Example: 101 = 1 + 1 = 2; 110 = 1 + 1 = 2; 100 = 2 + 1 = 3;
001 = 2 + 1 = 3; 111 = 0 + 1 = 1.
Note that only delay fraction values up to 47 decimal (101111b;
0x2F) are supported.
In no case can the fine delay exceed one-half of the output clock
period. If a delay longer than half of the clock period is attempted,
the output stops clocking.
The delay function adds some jitter that is greater than that
specified for the nondelayed output. This means that the delay
function should be used primarily for clocking digital chips,
such as FPGA, ASIC, DUC, and DDC. An output with this
delay enabled may not be suitable for clocking data converters.
The jitter is higher for long full scales because the delay block
uses a ramp and trip points to create the variable delay. A slower
ramp time produces more time jitter.
Synchronizing the Outputs—SYNC Function
The AD9516 clock outputs can be synchronized to each other.
Outputs can be individually excluded from synchronization.
Synchronization consists of setting the nonexcluded outputs to
a preset set of static conditions and, subsequently, releasing
these outputs to continue clocking at the same instant with the
preset conditions applied. This allows for the alignment of the
edges of two or more outputs or for the spacing of edges,
according to the coarse phase offset settings for two or more
outputs.
I
Number of Capacitors = Number of Bits =
0 in Ramp Capacitors + 1
Delay Range (ns) = 200 × ((No. of Caps + 3)/(I
Delay Full Scale (ns) = Delay Range + Offset
Fine Delay (ns) =
Delay Range × Delay Fraction × (1/63) + Offset
Offset
RAMP
(μA) = 200 × (Ramp Current + 1)
( )
ns
=
0.34
+
(
1600
−
I
RAMP
)
×
10
−
4
+
⎛
⎜
⎜
⎝
RAMP
No.
of
)) × 1.3286
I
RAMP
Caps
−
Rev. A | Page 46 of 80
1
⎞
× ⎟ ⎟
⎠
6
Synchronization of the outputs is executed in several ways,
as follows:
•
•
•
•
•
•
The most common way to execute the SYNC function is to use
the SYNC pin to do a manual synchronization of the outputs.
This requires a low-going signal on the SYNC pin, which is held
low and then released when synchronization is desired. The
timing of the SYNC operation is shown in
VCO divider) and
an uncertainty of up to one cycle of the clock at the input to the
channel divider due to the asynchronous nature of the SYNC
signal with respect to the clock edges inside the AD9516. The
delay from the
output clocking is between 14 and 15 cycles of clock at the
channel divider input, plus either one cycle of the VCO divider
input (see
(see
Cycles are counted from the rising edge of the signal.
Another common way to execute the SYNC function is by
setting and resetting the soft sync bit at Register 0x230[0] (see
Table 53 through Table 62 for details). Both setting and
resetting of the soft sync bit require an update all registers
operation (Register 0x232[0] = 1) to take effect.
Figure 58
By forcing the SYNC pin low and then releasing it (manual
sync).
By setting and then resetting any one of the following three
bits: the soft sync bit (Register 0x230[0]), the soft reset bit
(Register 0x000[2] [mirrored]), and the power-down
distribution reference bit (Register 0x230[1]).
By executing synchronization of the outputs as part of the
chip power-up sequence.
By forcing the RESET pin low and then releasing it (chip
reset).
By forcing the PD pin low and then releasing it (chip power-
down).
Following completion of a VCO calibration. An internal
SYNC signal is automatically asserted at the beginning and
released upon the completion of a VCO calibration.
Figure 57
), depending on whether the VCO divider is used.
SYNC rising edge to the beginning of synchronized
Figure 58
) or one cycle of the channel divider input
(VCO divider not used). There is
Figure 57
(using