842023 Datasheet, PDF (1/15 Pages) Integrated Device Technology – Femtoclock™ Crystal-to-HSTL Clock Generator

Femtoclock™ Crystal-to-HSTL Clock
Generator
842023
DATA SHEET
General Description
The 842023 is an Ethernet Clock Generator. For Ethernet
applications, a 25MHz crystal is used to generate 250MHz. The
842023 uses IDT 3^rd generation low phase noise VCO technology
and can achieve <1ps rms phase jitter, easily meeting Ethernet jitter
requirements. The 842023 is packaged in a small 8-pin TSSOP,
making it ideal for use in systems with limited board space.
Features
• One differential HSTL output pair
• Crystal oscillator interface, 18pF parallel resonant crystal
(24.5MHz – 34MHz)
• Output frequency range: 245MHz – 340MHz
• VCO range: 490MHz – 680MHz
• RMS phase jitter at: 250MHz, using a 25MHz crystal (1.875MHz –
20MHz): 0.36ps (typical)
• Full 3.3V or 2.5V output supply modes
• 0°C to 70°C ambient operating temperature
• Available in lead-free (RoHS 6) packaging
Frequency Table
Crystal Frequency (MHz)
25
Inputs
M
N
20
2
Multiplication Value M/N
10
Output Frequency (MHz)
250
Block Diagram
OE ^Pullup
XTAL_IN
XTAL_OUT
OSC
Phase
Detector
VCO
490MHz - 680MHz
N = ÷2 (fixed)
M = ÷20 (fixed)
Pin Assignment
VDDA 1
8 VDD
GND 2
7Q
XTAL_OUT 3
6 nQ
Q
XTAL_IN 4
5 OE
nQ
842023
8 Lead TSSOP
4.40mm x 3.0mm x 0.925 package body
G Package
Top View
842023 Rev A 8/14/15
1
©2015 Integrated Device Technology, Inc.