Rainbow Electronics MAX3622 User Manual
MAX3622
Low-Jitter, Precision Clock Generator
with Two Outputs
________________________________________________________________
Maxim Integrated Products
1
19-2456; Rev 0; 11/07
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.
EVALUATION KIT
AVAILABLE
General Description
The MAX3622 is a low-jitter precision clock generator
optimized for networking applications. The device integrates a crystal oscillator and a phase-locked loop
(PLL) clock multiplier to generate high-frequency clock
outputs for Ethernet and other networking applications.
Maxim’s proprietary PLL design features ultra-low jitter
(0.36ps
RMS
) and excellent power-supply noise rejec-
tion, minimizing design risk for network equipment.
The MAX3622 has one LVPECL output and one
LVCMOS output. It is available in a 16-pin TSSOP package and operates over the 0°C to +70°C temperature
range.
Applications
Ethernet Networking Equipment
Features
♦ Crystal Oscillator Interface: 25MHz Typical
♦ Output Frequencies: 125MHz and 156.25MHz
♦ 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
CRYSTAL
OSCILLATOR
X_IN
X_OUT
PFD FILTER
RESET
RESET
RESET LOGIC/POR
÷ 25
RESET
÷ 4
÷ 5
VCO
LVCMOS
BUFFER
QA_C
QAC_OE
LVPECL
BUFFER
QB
QB_OE
QB
MAX3622
RESET
625MHz
25MHz
33pF
27pF
Block Diagram
+
Denotes a lead-free package.
Typical Application Circuit and Pin Configuration appear
at end of data sheet.
PART TEMP RANGE
MAX3622CUE+ 0°C to +70°C 16 TSSOP U16-2
PINPACKAGE
PKG
CODE
MAX3622
Low-Jitter, Precision Clock Generator
with Two Outputs
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC= +3.0V to +3.6V, TA= 0°C to +70°C, unless otherwise noted. Typical values are at VCC= +3.3V, TA= +25°C, unless otherwise
noted.) (Notes 1, 2)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Supply Voltage Range VCC, V
CCA
,
V
DDO_A
, V
CCO_B
...............................................-0.3V to +4.0V
Voltage Range at QAC_OE, QB_OE,
RES1, RES2............................................-0.3V to (V
CC
+ 0.3V)
Voltage Range at X_IN Pin ....................................-0.3V to +1.2V
Voltage Range at GNDO_A...................................-0.3V to +0.3V
Voltage Range at X_OUT Pin ......................-0.3V to (V
CC
- 0.6V)
Current into QA_C ............................................................±50mA
Current into QB, QB...........................................................-56mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TSSOP (derate 11.1mW/°C above +70°C) .......889mW
Operating Junction Temperature Range...........-55°C to +150°C
Storage Temperature Range .............................-65°C to +160°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Power-Supply C urrent ICC (Note 3) 70 90 mA
CONTROL INPUT CHARACTERISTICS (QAC_OE, QB_OE PINS)
Input Capacitance C
Input Logic Bia s Resistor R
LVPECL OUTPUT SPECIFICATIONS (QB, QB PINS)
Output High Voltage V
Output Low Voltage V
Peak-to-Peak Output-Voltage
Swing (Single-Ended)
Output Rise/Fall Time 20% to 80% 200 350 600 ps
Output Duty-Cycle Distortion 48 50 52 %
LVCMOS/LVTTL INPUT SPECIFICATIONS (QAC_OE, QB_OE PINS)
Input-Voltage High VIH 2.0 V
Input-Voltage Low V
Input High Current I
Input Low Current I
LVCMOS OUTPUT SPECIFICATIONS (QA_C PIN)
Output High Voltage VOH QA_C sourcing 12mA 2.6 V
Output Low Voltage V
Output Rise/Fall Time (Note 4) 250 500 1000 ps
Output Duty-Cycle Distortion (Note 4) 42 50 58 %
Output Impedance 14
BIAS
OH
OL
IH
OL
2 pF
IN
50 k
0.6 0.72 0.9 V
0.8 V
IL
VIN = V
CC
VIN = 0V -80 μA
IL
QA_C sink ing 12mA 0.4 V
VCC -
1.13
VCC -
1.85
VCC -
0.98
VCC -
1.7
80 μA
VCC -
0.83
VCC -
1.55
V
V
P-P
MAX3622
Low-Jitter, Precision Clock Generator
with Two Outputs
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VCC= +3.0V to +3.6V, TA= 0°C to +70°C, unless otherwise noted. Typical values are at VCC= +3.3V, TA= +25°C, unless otherwise
noted.) (Notes 1, 2)
Note 1: A series resistor of up to 10.5Ω is allowed between VCCand V
CCA
for filtering supply noise when system power-supply
tolerance is V
CC
= 3.3V ±5%. See Figure 2.
Note 2: LVPECL terminated with 50Ω load connected to V
TT
= VCC- 2V.
Note 3: Both outputs enabled and unloaded.
Note 4: Measured using setup shown in Figure 1 with V
CC
= 3.3V ±5%.
Note 5: Measured with Agilent DSO81304A 40GS/s real-time oscilloscope.
Note 6: Measured with 40mV
P-P
, 100kHz sinusoidal signal on the supply with V
CCA
connected as shown in Figure 2.
Figure 1. LVCMOS Output Measurement Setup
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
CLOCK OUTPUT AC SPECIFICATIONS
VCO Frequency Range 620 625 648 MHz
Random Jitter RJ
Determin istic Jitter Induced by
Power-Supply Nois e
(Notes 5, 6)
Spurs Induced by Power-Supply
Noise (Note 6)
Nonharmonic and Subharmonic
Spurs
Clock Output SSB Phase Noise
at 125MHz
RMS
12kHz to 20MHz 0.36 1.0
1.875MHz to 20MHz 0.14
LVPECL o utput 4
LVCMOS output 19
LVPECL o utput -57
LVCMOS output -47
-70 dBc
f = 1kHz -124
f = 10kHz -126
f = 100kHz -130
f = 1MHz -145
f > 10MH z -153
ps
RMS
ps
P-P
dBc
dBc/Hz
MAX3622
QA_C
36Ω 499Ω
4.7pF
0.1μF
OSCILLOSCOPE
Z0 = 50Ω
50Ω
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