ACS8510 Semtech, ACS8510 Datasheet - Page 14

• Manufacturer Part Number: ACS8510
• Manufacturer: Semtech

Specifications of ACS8510

• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6/5.5V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Package Type: LQFP
• Mounting: Surface Mount
• Pin Count: 100
• Lead Free Status / Rohs Status: Not Compliant

Table 5. Input Reference Source Jitter Tolerance
Table 5. Input Reference Source Jitter Tolerance
tolerance masks are specified in Figures 3 and
4, and Tables 6 and 7, respectively. The
ACS8510 will tolerate wander and jitter
components greater than those shown in Figure
3 and Figure 4, up to a limit determined by a
combination of the apparent long-term
frequency offset caused by wander and the
eye-closure caused by jitter (the input source
will be rejected if the offset pushes the
frequency outside the hold-in range for long
enough to be detected, whilst the signal will
also be rejected if the eye closes sufficiently to
affect the signal purity). The ‘8klocking’ mode
should be engaged for high jitter tolerance
according to these masks. All reference clock
ports are monitored for quality, including
frequency offset and general activity. Single
short-term interruptions in selected reference
clocks may not cause rearrangements, whilst
longer interruptions, or multiple, short-term
interruptions, will cause rearrangements, as will
frequency offsets which are sufficiently large
or sufficiently long to cause loss-of-lock in the
Table 5. Input Reference Source Jitter Tolerance
Table 5. Input Reference Source Jitter Tolerance
Table 5. Input Reference Source Jitter Tolerance
Revision 2.00/September 2003
ADVANCED COMMUNICATIONS
Notes for Table 5.
Notes for Table 5.
Notes for Table 5.
Note 1. The frequency acceptance and generation range will be +/-4.6 ppm around the required frequency when the
external crystal frequency accuracy is within a tolerance of +/- 4.6 ppm.
Note 2. The fundamental acceptance range and generation range is +/- 9.2 ppm with an exact external crystal
frequency of 12.8 MHz. This is the default DPLL range, the range is also programmable from 0 to 80 ppm in 0.08
ppm steps.
Notes for Table 5.
Notes for Table 5.
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R
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J
G
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7 .
8 .
4
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n
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3
3
3
e c
e c
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e c
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O
R
E
F
F
F
F
F
A
A
A
A
A
e r
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e r
e r
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c
c
c
c
c
e c
e c
e c
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q
q
q
q
q
+
u
u
u
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p
p
p
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p
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a t
a t
a t
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Semtech Corp.
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y c
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6 .
e c
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M
M
M
M
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t i
t i
t i
t i
t i
g
g
g
g
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r o
r o
r o
r o
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e
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c
c
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+
+
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P (
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- /
- /
e e
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a t
a t
a t
a t
a t
q
q
q
q
q
l u
l u
l u
l u
l u
4
9
n
n
n
n
n
N
N
u
u
u
u
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6 .
2 .
14
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i - l
i - l
i - l
i - l
i - l
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p
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phase-locked loop. The failed reference source
will be removed from the priority table and
declared as unserviceable, until its perceived
quality has been restored to an acceptable
level.
The registers sts_curr_inc_offset (address 0C,
0D, 07) report the frequency of the DPLL with
respect to the external TCXO frequency. This is
a 19 bit signed number with one LSB
representing 0.0003 ppm (range of +/- 80
ppm). Reading this regularly can show how the
currently locked source is varying in value e.g.
due to wander on its input.
The ACS8510 performs automatic frequency
monitoring with an acceptable input frequency
offset range of +/- 16.6 ppm. The ACS8510
DPLL has a programmable frequency limit of
+/- 80 ppm. If the range is programmed to be
> 16.6 ppm, the frequency monitors should be
disabled so the input reference source is not
automatically rejected as out of frequency
range.
p
p
R
R
R
R
R
y c
y c
y c
y c
y c
) 1
) 2
m
m
a
a
a
a
a
ACS8510 Rev2.1 SETS
n
n
n
n
n
g
g
g
g
g
e
e
e
e
e
R
R
R
R
R
a
a
a
a
a
A
A
A
A
A
s (
s (
F
F
F
n
n
n
n
n
+
+
F
F
c
c
c
c
c
e r
e r
e r
e r
e r
- /
- /
g
g
g
g
g
e e
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e
e
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q
q
q
q
q
4
9
p
p
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u
u
u
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6 .
2 .
a t
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d l
d l
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d l
d l
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) 1
) 2
m
m
i -
i -
i -
i -
i -
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A
A
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A
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c
c
c
c
c
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+
+
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p
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www.semtech.com
a t
a t
a t
a t
a t
u
u
u
u
u
q
q
q
q
q
4
9
n
n
n
l l
l l
l l
n
n
l l
l l
N
N
u
u
u
u
u
6 .
2 .
e c
e c
e c
o -
o -
o -
e c
e c
o -
o -
o
o
e
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e
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p
p
n
n
n
n
n
u
u
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u
FINAL
R
R
R
p
p
R
R
y c
y c
y c
y c
y c
) t
) t
) t
) t
) t
) 1
) 2
m
m
a
a
a
a
a
n
n
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n
n
g
g
g
g
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