Silicon Laboratories Si5310-EVB, Руководство пользователя

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Si5310-EVB
Rev. 0.71 3
Figure 1. MULTSEL Jumper Configurations
Loss-of-Lock (LOL)
LOL is an indicator of the relative frequency between
the REFCLK input, which is nominally a multiple of
CLKIN, and an internally generated multiple of CLKIN.
LOL will assert when the frequency difference is greater
than ±600 PPM. In order to prevent LOL from de-
asserting prematurely, there is hysterisis in returning
from the out of lock condition. LOL will be de-asserted
(indicating a lock condition) when the frequency
difference is less than ±300 PPM.
LOL is wired to a test point which is located on the
upper right-hand side of the evaluation board.
Test Configuration
The characterization of clock sources typically involves
measuring the output jitter or phase noise of the source.
The overall output jitter is a function of the input jitter
(jitter transfer) and the jitter generated (output jitter) by
the internal PLL.
Jitter can be measured using several different
techniques and hardware. An oscilloscope, a spectrum
analyzer, and a phase-noise analyzer are three such
instruments capable of measuring output jitter. A
spectrum analyzer is the best choice for measuring jitter
transfer.
Output Jitter
Output jitter is a measure of the output clock short-term
stability. In Figure 2, either position A or B can be used
when measuring this parameter.
Oscilloscope
An oscilloscope can measure jitter from the clock edges
within the trigger-to-capture bandwidth. Typically the
jitter measured is expressed in picoseconds (peak-to-
peak and RMS) relative to the average edge position. A
histogram can be used to capture the jitter distribution.
Table 1. CLKIN, CLKOUT, MULTOUT, REFCLK Operating Ranges
MULTSEL CLKIN Range
(MHz)
REFCLK = 2
n
x CLKIN
±100 ppm
(see Note 2)
CLKOUT MULTOUT
0
(MULTOUT = 600–668 MHz)
37.500–41.750 n = –2, –1, 0, 1, or 2 1xCLKIN 16xCLKIN
75.000–83.500 n = –3, –2, –1, 0, or 1 1xCLKIN 8xCLKIN
150.000–167.000 n = –4, –3, –2, –1, or 0 1xCLKIN 4xCLKIN
300.000–334.000 n = –5, –4, –3, –2, or –1 1xCLKIN 2xCLKIN
600.000–668.000 n = –6, –5, –4, –3, or –2 See Note 1 1xCLKIN
1
(MULTOUT = 150–167 MHz)
9.375–10.438 n = 0, 1, 2, 3, or 4 1xCLKIN 16xCLKIN
18.750–20.875 n = –1, 0, 1, 2, or 3 1xCLKIN 8xCLKIN
37.500–41.750 n = –2, –1, 0, 1, or 2 1xCLKIN 4xCLKIN
75.000–83.500 n = –3, –2, –1, 0, or 1 1xCLKIN 2xCLKIN
150.000–167.000 n = –4, –3, –2, –1, or 0 See Note 1 1xCLKIN
Note:
1. The CLKOUT output is not valid for MULTOUT:CLKIN ratios of 1:1 (MULTOUT = 1 x CLKIN.)
2. The REFCLK input can be set to any one of the five CLKIN multiples indicated. The REFCLK input can be
asynchronous to the CLKIN input, but must be within ±100 ppm of the stated CLKIN multiple.
GN
D
2.
5 V
M ULTSEL
Low Range
15 0–167 MHz
GN
D
2.
5 V
M ULTSEL
High Range
60 0–668 MHz
MU L TSEL
PWR D N /
C AL
MU LTSEL
PWR D N /
C AL