844003I-04 Datasheet, PDF (1/19 Pages) Integrated Device Technology – FemtoClock Crystal-to-LVDS Frequency Synthesizer

FemtoClock^® Crystal-to-LVDS Frequency
Synthesizer
844003I-04
Datasheet
General Description
The 844003I-04 is a 3 differential output LVDS Synthesizer designed
to generate Ethernet reference clock frequencies. Using a
19.44MHz, 20MHz or 25MHz, 18pF parallel resonant crystal, the
following frequencies can be generated based on the settings of four
frequency select pins (DIV_SELA[1:0], DIV_SELB[1:0]): 625MHz,
622.08MHz, 312.5MHz, 250MHz, 156.25MHz, 125MHz and
100MHz. The 844003I-04 has two output banks, Bank A with one
differential LVDS output pair and Bank B with two differential LVDS
output pairs.
The two banks have their own dedicated frequency select pins and
can be independently set for the frequencies mentioned above. The
844003I-04 uses IDT’s 3^RD generation low phase noise VCO
technology and can achieve 1ps or lower typical rms phase jitter,
easily meeting Ethernet jitter requirements. The 844003I-04 is
packaged in a 32-pin VFQFN package.
Features
• Three LVDS outputs on two banks, Bank A with one LVDS pair
and Bank B with 2 LVDS output pairs
• Using a 19.44MHz, 20MHz, or 25MHz crystal, the two output
banks can be independently set for 625MHz, 622.08MHz,
312.5MHz, 250MHz, 156.25MHz, 125MHz or 100MHz
• Selectable crystal oscillator interface or LVCMOS/LVTTL
single-ended input
• VCO range: 490MHz to 680MHz
• RMS phase jitter at 125MHz (1.875MHz – 20MHz):
0.50ps (typical)
• Full 3.3V output supply mode
• -40°C to 85°C ambient operating temperature
• Available in lead-free (RoHS 6) package
• For functional replacement part use 8T49N241
Pin Assignment
Block Diagram
OEA
DIV_SELA[1:0]
VCO_SEL
Pullup
Pulldown:Pullup
Pullup
REF_CLK ^Pulldown
0
XTAL_IN
OSC
1
XTAL_OUT
XTAL_SEL ^Pullup
FB_DIV ^Pulldown
DIV_SELB[1:0] ^{Pulldown:Pullup}
MR
OEB
Pulldown
Pullup
Phase
Detector
VCO
490-680MHz
FB_DIV
0 = ÷25 (default)
1 = ÷32
©2016 Integrated Device Technology, Inc.
GND
XTAL_IN
XTAL_OUT
XTAL_SEL
VCO_SEL
MR
32 31 30 29 28 27 26 25
1
24
2
844003I-04
23
3 ^{32 Lead VFQFN} 22
4 ^{5mm x 5mm x 0.925mm} 21
package body
5
K Package
20
6
Top View
19
QA0
nQA0
GND
QB0
nQB0
QB1
GND 7
18 nQB1
nc 8
17 VDDO_B
9 10 11 12 13 14 15 16
0 0 ÷2
0 1 ÷4 (default)
0
1 0 ÷5
1 1 ÷8
1
0 0 ÷1
0 1 ÷2 (default)
1 0 ÷3
1 1 ÷4
QA0
nQA0
QB0
nQB0
QB1
nQB1
1
Revision C, November 10, 2016