ACS8510 Semtech, ACS8510 Datasheet - Page 19

• 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

1. ETSI 300 462-5, Section 9.1, requires that the short-
term phase error during switchover (i.e., Locked to Holdover
to Locked) be limited to an accumulation rate no greater
than 0.05 ppm during a 15 second interval.
2. ETSI 300 462-5, Section 9.2, requires that the long-
term phase error in the Holdover mode should not
exceed
where
Revision 2.00/September 2003
Figure 5. Wander and Jitter Measured Transfer Characteristics
Figure 5. Wander and Jitter Measured Transfer Characteristics
Figure 5. Wander and Jitter Measured Transfer Characteristics
Figure 5. Wander and Jitter Measured Transfer Characteristics
Figure 5. Wander and Jitter Measured Transfer Characteristics
a2 = 2000 ns/s (allowance for temperature variation)
b = 1.16x10
c = 120 ns (allowance for entry into Holdover mode).
ADVANCED COMMUNICATIONS
a1 = 50 ns/s (allowance for initial frequency offset)
-4
ns/s
-10
-15
-20
-25
-30
-3
-5
5
0
{(a1+a2)S+0.5bS
0.01
2
(allowance for ageing)
Semtech Corp.
0.1
2
+c}
0.1 Hz
0.3 Hz
0.5 Hz
1.0 Hz
2.0 Hz
4.0 Hz
8.0 Hz
17 Hz
1
19
3. ANSI Tin1.101-1994, Section 8.2.2, requires that the
phase variation be limited so that no more than 255 slips
(of 125 µs each) occur during the first day of Holdover.
This requires a frequency accuracy better than:
Temperature variation is not restricted, except to within
the normal bounds of 0 to 50 °C.
4. Telcordia GR.1244.CORE, Section 5.2., Table 4, shows
that an initial frequency offset of 50 ppb is permitted on
entering Holdover, whilst a drift over temperature of
280 ppb is allowed; an allowance of 40 ppb is permitted
for all other effects.
5. ITU G.822, Section 2.6, requires that the slip rate during
category(b) operation (interpreted as being applicable to
Holdover mode operation) be limited to less than 30 slips
(of 125 µs each) per hour
((24x60x60)+(255x125µs))/(24x60x60) = 0.37 ppm
ACS8510 Rev2.1 SETS
((((60 x 60)/30)+125µs)/(60x60)) = 1.042 ppm
10
Frequency (Hz)
100
1000
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FINAL