MAX3679 Datasheet, PDF (1/11 Pages) Maxim Integrated Products – +3.3V, Low-Jitter Crystal to LVPECL Clock Generator

19-4374; Rev 0; 11/08
EVAALVUAAILTAIOBNLEKIT
+3.3V, Low-Jitter Crystal to LVPECL
Clock Generator
General Description
The MAX3679 is a low-jitter precision clock generator
with the integration of three LVPECL and one LVCMOS
outputs optimized for Ethernet applications. The device
integrates a crystal oscillator and a phase-locked loop
(PLL) clock multiplier to generate high-frequency clock
outputs for Ethernet applications.
Maxim’s proprietary PLL design features ultra-low jitter
(0.36ps_RMS) and excellent power-supply noise rejection,
minimizing design risk for network equipment.
Applications
Ethernet Networking Equipment
Pin Configuration appears at end of data sheet.
Features
♦ Crystal Oscillator Interface: 25MHz
♦ CMOS Input: 25MHz
♦ Output Frequencies for Ethernet
62.5MHz, 125MHz, 156.25MHz, 312.5MHz
♦ Low Jitter
0.14ps_RMS (1.875MHz to 20MHz)
0.36ps_RMS (12kHz to 20MHz)
♦ Excellent Power-Supply Noise Rejection
♦ No External Loop Filter Capacitor Required
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX3679CTJ+
0°C to +70°C
32 TQFN-EP*
+Denotes a lead-free/RoHS-compliant package.
*EP = Exposed pad.
Typical Application Circuit
10.5Ω
0.1μF
0.1μF
0.1μF
0.01μF
0.1μF
+3.3V ±5%
10μF
0.1μF
V_CC
V_CC
V_CCA
MR
REF_IN
V_{CCO_A}
V_{CCO_B}
IN_SEL
QAC_OE
QA_OE
QB0_OE
QB1_OE
MAX3679
BYPASS
SELA1
SELA0
SELB1
SELB0
RES1
RES0
X_OUT
X_IN
GND
25MHz
(C_L = 18pF)
V_{DDO_A}
36Ω
QA_C
125MHz
QA
Z₀ = 50Ω
QA
Z₀ = 50Ω
125MHz
QB0
Z₀ = 50Ω
QB0
Z₀ = 50Ω
312.5MHz
QB1
Z₀ = 50Ω
QB1
Z₀ = 50Ω
312.5MHz
GNDO_A
33pF
27pF
Z₀ = 50Ω
ASIC
ASIC
50Ω 50Ω
(V_CC - 2V)
ASIC
50Ω 50Ω
(V_CC - 2V)
ASIC
50Ω 50Ω
(V_CC - 2V)
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.