84321I Datasheet, PDF (1/18 Pages) Integrated Device Technology – 260MHz, Crystal-to-3.3V Differential

260MHz, Crystal-to-3.3V Differential
LVPECL Clock Synthesizer
84321I
DATA SHEET
GENERAL DESCRIPTION
The 84321I is a general purpose, dual output Crystal-to-3.3V
Differential LVPECL High Frequency Synthesizer The 84321I
has a selectable TEST_CLK or crystal inputs.The VCO operates
at a frequency range of 620MHz to 780MHz. The VCO frequency
is programmed in steps equal to the value of the input
reference or crystal frequency. The VCO and output
frequency can be programmed using the serial or parallel
interfaces to the confi guration logic. The low phase noise
characteristics of the 84321I make it an ideal clock source
for Fibre Channel 1, Fibre Channel 2, 10 Gigabit Fibre
Channel, Gigabit Ethernet and 10 Gigabit Ethernet
applications.
BLOCK DIAGRAM
FEATURES
• Dual differential 3.3V LVPECL outputs
• Selectable crystal oscillator interface
or LVCMOS/LVTTL TEST_CLK
• Output frequency range: 103.3MHz to 260MHz
• Crystal input frequency range: 14MHz to 40MHz
• VCO range: 620MHz to 780MHz
• Parallel or serial interface for programming counter
and output dividers
• RMS period jitter: 3ps (typical)
• RMS phase jitter at 155.52MHz, using a 38.88MHz crystal
(12kHz to 20MHz): 2.5ps (typical)
Phase noise: 155.52MHz
Offset
Noise Power
100Hz ..................-84.1 dBc/Hz
1kHz ................-109.8 dBc/Hz
10kHz ................-126.3 dBc/Hz
100kHz ................-128.7 dBc/Hz
• 3.3V supply voltage
• -40°C to 85°C ambient operating temperature
• Available in lead-free (RoHS 6) package
• For functional replacement part use 8T49N241
PIN ASSIGNMENT
84321I REVISION B 11/5/15
32 31 30 29 28 27 26 25
M5 1
24 XTAL2
M6 2
23 TEST_CLK
M7 3
22 XTAL_SEL
M8 4
N0 5
84321I
21 VCCA
20 S_LOAD
N1 6
19 S_DATA
nc 7
18 S_CLOCK
VEE 8
17 MR
9 10 11 12 13 14 15 16
32-Lead LQFP
7mm x 7mm x 1.4mm package body
Y Package
Top View
1
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