840N022 Datasheet, PDF (1/13 Pages) Integrated Device Technology – FemtoClock® NG Crystal-to-LVCMOS/LVTTL Clock

FemtoClock® NG
Crystal-to-LVCMOS/LVTTL Clock
840N022
DATA SHEET
General Description
The 840N022 is a LVCMOS/LVTTL clock synthesizer designed for
Ethernet applications. The device generates a selectable 125MHz or
62.5MHz clock signal with excellent phase jitter performance. The
device uses IDT’s fourth generation FemtoClock® NG technology
for an optimum of high clock frequency, low phase noise
performance and low power consumption.The device supports 2.5V
or 3.3V voltage supply and is packaged in a small, lead-free (RoHS
6) 8-lead TSSOP package. The extended temperature range
supports wireless infrastructure, telecommunication, and networking
end equipment requirements.
FREQ_SEL Frequency Table
Input
Output Frequency
FREQ_SEL
0 (default)
f_XTAL = 25MHz
125MHz
f_XTAL = 20MHz
100MHz
1
62.5MHz
50MHz
NOTE: FREQ_SEL is an asynchronous control.
Features
• Fourth generation FemtoClock® NG technology
• 125MHz output clock synthesized from a 25MHz fundamental
mode crystal
• One LVCMOS/LVTTL clock output
• Crystal interface designed for a 12pF parallel resonant crystal
• RMS phase jitter @ 125MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.148ps (maximum)
• RMS phase jitter @ 125MHz, using a 25MHz crystal
(12kHz - 20MHz): 0.479ps (maximum)
• LVCMOS interface levels for the control inputs
• Full 2.5V or 3.3V supply voltage
• Lead-free (RoHS 6) packaging
• -40°C to 85°C ambient operating temperature
• Use replacement part: 840N202CKI-dddLF
OE Function Table
Input
OE
Output Enable
0
Output Q is disabled in high-impedance state
1 (default)
Output Q is enabled.
NOTE: OE is an asynchronous control.
Block Diagram
XTAL_IN
XTAL_OUT
OSC
PFD
&
LPF
FemtoClock^® NG
VCO
490-637.5MHz
÷5,
÷10
Q
÷25
FREQ_SEL
OE
Pulldown
Pullup
Pin Assignment
VDDA 1
OE 2
XTAL_OUT 3
XTAL_IN 4
8 VDD
7Q
6 GND
5 FREQ_SEL
840N022
8-lead TSSOP
4.40mm x 3.0mm x 0.925mm
package body
G Package
Top View
840N022 REVISION A 8/14/15
1
©2015 Integrated Device Technology, Inc.