19-4467; Rev 0; 2/09
+3.3V, Low-Jitter, Precision Clock Generator
with Multiple Outputs
MAX3629
General Description
Features
The MAX3629 is a low-jitter precision clock generator
optimized for network applications. The device inte-
grates a crystal oscillator and a phase-locked loop
(PLL) to generate high-frequency clock outputs for
Ethernet applications.
♦ Crystal Oscillator Interface: 25MHz
♦ OSC_IN Interface:
PLL Enabled: 25MHz
PLL Disabled: 20MHz to 320MHz
♦ Outputs:
Maxim’s proprietary PLL design features ultra-low jitter
One LVDS Output at 125MHz/156.25MHz/
312.5MHz (Selectable with FSELA)
Four LVDS Outputs at 125MHz/156.25MHz/
312.5MHz (Selectable with FSELB)
Three LVCMOS Outputs at 125MHz/156.25MHz
(Selectable with FSELB)
(0.4ps
) and excellent power-supply noise rejection
RMS
(PSNR), minimizing design risk for network equipment.
The MAX3629 contains five LVDS outputs and three
LVCMOS outputs. The output frequencies are selec-
table among 125MHz, 156.25MHz, and 312.5MHz by
pin control.
♦ Low Phase Jitter: 0.4ps
♦ Excellent PSNR
(12kHz to 20MHz)
RMS
Applications
Ethernet Networking Equipment
♦ Operating Temperature Range: 0°C to +70°C
Typical Operating Circuit
Ordering Information
+3.3V 5%
PART
TEMP RANGE
PIN-PACKAGE
0.1μF
0.1μF
0.1μF
MAX3629CTJ+
0°C to +70°C
32 TQFN-EP*
10.5Ω
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
V
V
V
DDO_SE
DD
DDO_DIFF
10μF
Q0
Z = 50Ω
0
V
DDA
125MHz/156.25MHz/
312.5MHz
100Ω
100Ω
100Ω
100Ω
100Ω
ASIC
ASIC
ASIC
ASIC
ASIC
ASIC
ASIC
ASIC
0.01μF
Q0
Q1
Z
= 50Ω
0
Pin Configuration
OSC_IN
Z
= 50Ω
0
125MHz/156.25MHz/
312.5MHz
MAX3629
TOP VIEW
Q1
Q2
Z
0
= 50Ω
33pF
X_OUT
X_IN
Z
= 50Ω
0
25MHz
(C = 18pF)
24 23 22 21 20 19 18 17
125MHz/156.25MHz/
312.5MHz
L
16
15
V
DDA
25
FSELB
Q2
Q3
Z
0
= 50Ω
27pF
RESERVED
PLL_BP 26
V
Z
= 50Ω
0
125MHz/156.25MHz/
312.5MHz
14 Q4
27
28
29
30
31
32
DD
V
DD
PLL_BP
Q3
Q4
Z
0
= 50Ω
FSELA
Q4
V
13
12
MAX3629
OSC_IN
X_IN
Z
0
= 50Ω
DDO_DIFF
125MHz/156.25MHz/
312.5MHz
11 Q3
Q4
Q5
Z = 50Ω
0
GND, OPEN, OR V
GND, OPEN, OR V
FSELA
FSELB
DD
*EP
10
9
Q3
X_OUT
GND
+
GND
125MHz/156.25MHz
= 50Ω
33Ω
33Ω
33Ω
DD
Z
0
1
2
3
4
5
6
7
8
125MHz/156.25MHz
= 50Ω
GND
Q6
Q7
Z
0
THIN QFN-EP
(5mm × 5mm)
125MHz/156.25MHz
= 50Ω
Z
0
*EXPOSED PAD CONNECTED TO GROUND.
________________________________________________________________ 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.