ACS8520A 데이터 시트보기 (PDF) - Semtech Corporation
부품명
상세내역
제조사
ACS8520A Datasheet PDF : 150 Pages
| |||
ACS8520A SETS
ADVANCED COMMS & SENSING
FINAL
DATASHEET
frequency to 8 kHz, the post-division frequency. PECL/LVDS/AMI Input Port Selection
(XX = “Leaky Bucket” ID for this input).
The choice of PECL or LVDS compatibility is programmed
(ii) To achieve 8 kHz, the 10 MHz input must be
divided by 1,250. So, if DivN, = 250 = (N+1)
then N must be set to 1,249. This is done by
writing 4E1 hex (1,249 decimal) to the DivN
via the cnfg_differential_inputs register. Unused PECL
differential inputs should be fixed with one input High
(VDD) and the other input Low (GND), or set in LVDS mode
and left floating, in which case one input is internally
pulled High and the other Low.
register pair Reg. 46/Reg. 47.
An AMI port supports a composite clock, consisting of a
Direct Lock Mode 155 MHz.
The max frequency allowed for phase comparison is
77.76MHz, so for the special case of a 155 MHz input set
to Direct Lock Mode, there is a divide-by-two function
automatically selected to bring the frequency down to
64 kHz AMI clock with 8 kHz boundaries marked by
deliberate violations of the AMI coding rules, as specified
in ITU recommendation G.703[6]. Departures from the
nominal pattern are detected within the ACS8520A, and
may cause reference-switching if too frequent. See
section DC Characteristics: AMI Input/Output Port, for
more details. If the AMI port is unused, the pins (I1 and I2)
within the limits of operation.
should be tied to GND.
Table 4 Input Reference Source Selection and Priority Table
Port Number Channel
Number (Bin)
Input Port
Technology
Frequencies Supported
Default
Priority
I1
0001
AMI
64/8 kHz (composite clock, 64 kHz + 8 kHz)
2
Default (SONET): 64/8 kHz Default (SDH): 64/8 kHz
I2
0010
AMI
64/8 kHz (composite clock, 64 kHz + 8 kHz)
3
Default (SONET): 64/8 kHz Default (SDH): 64/8 kHz
I3
0011
TTL/CMOS
Up to 100 MHz (see Note (i))
4
Default (SONET): 8 kHz Default (SDH): 8 kHz
I4
0100
TTL/CMOS
Up to 100 MHz (see Note (i))
5
Default (SONET): 8 kHz Default (SDH): 8 kHz
I5
0101
LVDS/PECL LVDS Up to 155.52 MHz (see Note (ii))
6
default
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
I6
0110
PECL/LVDS PECL Up to 155.52 MHz (see Note (ii))
7
default
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
I7
0111
TTL/CMOS
Up to 100 MHz (see Note (i))
8
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
I8
1000
TTL/CMOS
Up to 100 MHz (see Note (i))
9
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
I9
1001
TTL/CMOS
Up to 100 MHz (see Note (i))
10
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
I10
1010
TTL/CMOS
Up to 100 MHz (see Note (i))
11
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
I11
1011
TTL/CMOS
Up to 100 MHz (see Note (i)) Default (Master) (SONET): 1.544 MHz Default 12/1 (Note
(Master) (SDH): 2.048 MHz Default (Slave) 6.48 MHz
(iii))
I12
1100
TTL/CMOS
Up to 100 MHz (see Note (i))
13
Default (SONET): 1.544 MHz Default (SDH): 2.048 MHz
Revision 1.00/September 2007© Semtech Corp.
Page 11
www.semtech.com
Share Link: 