Rainbow Electronics MAX3679A User Manual
General description, Applications, Features
General Description
The MAX3679A 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
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
MAX3679A
+3.3V, Low-Jitter Crystal to LVPECL
Clock Generator
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
Typical Application Circuit
19-4858; Rev 0; 8/09
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.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
*
EP = Exposed pad.
EVALUATION KIT
AVAILABLE
Pin Configuration appears at end of data sheet.
PART
TEMP RANGE
PIN-PACKAGE
MAX3679AETJ+ -40
°C to +85°C 32
TQFN-EP*
MAX3679A
V
CCA
MR
REF_IN
IN_SEL
QA_OE
QAC_OE
QB0_OE
QB1_OE
BYPASS
SELA1
SELA0
SELB0
RES1
SELB1
RES0
QA_C
X_OUT
X_IN
GNDO_A
GND
V
CC
V
CCO_A
V
CCO_B
V
DDO_A
10.5
Ω
0.1
μF
V
CC
36
Ω
Z
0
= 50
Ω
ASIC
125MHz
QA
50
Ω
Z
0
= 50
Ω
QA
Z
0
= 50
Ω
ASIC
50
Ω
125MHz
(V
CC
- 2V)
QB0
50
Ω
Z
0
= 50
Ω
QB0
Z
0
= 50
Ω
ASIC
50
Ω
312.5MHz
(V
CC
- 2V)
QB1
50
Ω
Z
0
= 50
Ω
QB1
Z
0
= 50
Ω
ASIC
50
Ω
312.5MHz
(V
CC
- 2V)
10
μF
25MHz
(C
L
= 18pF)
33pF
27pF
0.01
μF
0.1
μF
0.1
μF
0.1
μF
0.1
μF
+3.3V
±5%