19-3942; Rev 0; 1/06
Factory-Programmable, Single PLL
Clock Generator
General Description
The MAX9491 multipurpose clock generator is ideal for
communication applications. It offers a factory-program-
mable PLL output that can be set to almost any frequency,
ranging from 4MHz to 200MHz. The MAX9491 uses a
one-time-programmable (OTP) ROM to program the PLL
output. The MAX9491 also features an integrated volt-
age-controlled crystal oscillator (VCXO) that is tuned by a
DC voltage. The VCXO output is used as the PLL input.
The VCXO has a wide ±200ppm (typ) tuning range. The
OTP on the MAX9491 is factory preset, based upon the
customer request. Contact the factory for samples with
preferred frequencies.
The device operates from a 3.3V supply and is speci-
fied over the -40°C to +85°C extended temperature
range. The MAX9491 is available in 14-pin TSSOP and
20-pin TQFN (5mm x 5mm) packages.
Features
♦
5MHz to 35MHz for Crystal-Clock Reference
♦
5MHz to 50MHz for a Driver Clock Reference
♦
One Fractional-N PLL with Buffered Output
♦
4MHz to 200MHz Output Frequency Range
♦
Low RMS Jitter PLL (< 13ps) at 197 MHz
♦
Integrated VCXO with ±200ppm Tuning Range
♦
Available in 14-Pin TSSOP and 20-Pin TQFN
Packages
♦
+3.3V Supply
♦
-40°C to +85°C Temperature Range
MAX9491
Applications
Telecommunications
Data Networking Systems
Home Entertainment Centers
SOHO
PART
MAX9491ETP
MAX9491EUD*
Ordering Information
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
20 TQFN-EP**
14 TSSOP
PKG
CODE
T2055-5
U14-2
*Future
product—contact factory for availability.
**EP
= Exposed pad.
Pin Configurations
GND
V
DD
13
TOP VIEW
15
V
DD
X2
X1
I.C.
I.C.
16
17
18
19
20
1
TUNE
14
12
V
DD
I.C.
PD
11
10
9
GND
I.C.
I.C.
I.C.
I.C.
TOP VIEW
X1 1
I.C. 2
I.C. 3
V
DD
4
TUNE 5
GND 6
14 X2
13 PD
12 V
DD
MAX9491
8
7
6
MAX9491
11 GND
10 I.C.
9
8
GND
I.C.
2
V
DDA
3
AGND
4
GND
5
CLK_OUT
CLK_OUT 7
TSSOP
TQFN (5mm x 5mm)
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Factory Programmable Single PLL
Clock Generator
MAX9491
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ...........................................................-0.3V to +4.0V
V
DDA
to AGND ......................................................-0.3V to +4.0V
All Other Pins to GND ..................................-0.3V to V
DD
+ 0.3V
Short-Circuit Duration
(all LVCMOS outputs)..............................................Continuous
ESD Protection (Human Body Model)..................................±2kV
Continuous Power Dissipation (T
A
= +70°C)
20-Lead TQFN (derate 21.3mW/°C above +70°C) ....2758mW
14-Pin TSSOP (derate 9.1mW/°C above +70°C) ......796.8mW
Storage Temperature Range .............................-65°C to +150°C
Maximum Junction Temperature .....................................+150°C
Operating Temperature Range ...........................-40°C to +85°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
DC ELECTRICAL CHARACTERISTICS
(V
DD
= V
DDA
= +3.0V to +3.6V and T
A
= -40°C to +85°C. Typical values at V
DD
= V
DDA
= 3.3V, T
A
= +25°C, unless otherwise noted.)
(Note 1)
PARAMETER
Input High Level
Input Low Level
High-Level Input Current
Low-Level Input Current
CLOCK OUTPUT (CLK_OUT)
Output High Level
Output Low Level
POWER SUPPLIES
Digital Power-Supply Voltage
Analog Power-Supply Voltage
Total Current for Digital and
Analog Supplies
Power-Down Current
V
DD
V
DDA
I
DC
I
DC
2
f
OUT
= 45MHz, no load
f
IN
= 13MHz
PD
= low
3.0
3.0
10
60
3.6
3.6
V
V
mA
µA
V
OH
V
OL
I
OH
= -4mA
I
OL
= 4mA
V
DD
-
0.6
0.4
V
V
SYMBOL
V
IH
V
IL
I
IH
I
IL
V
IN
= V
DD
V
IN
= 0
-20
CONDITIONS
MIN
2.0
0
TYP
MAX
V
DD
0.8
20
UNITS
V
V
µA
µA
LVCMOS INPUTS (PD, X1 as a reference INPUT CLK)
2
_______________________________________________________________________________________
Factory Programmable Single PLL
Clock Generator
AC ELECTRICAL CHARACTERISTICS
(V
DD
= V
DDA
= +3.0V to +3.6V, C
L
= 10pF and T
A
= -40°C to +85°C. Typical values are at V
DD
= V
DDA
= 3.3V, T
A
= +25°C, unless
otherwise noted.) (Note 2)
PARAMETER
OUTPUT CLOCK (CLK_OUT)
Minimum Frequency Range
Maximum Frequency Range
Clock Rise Time
Clock Fall Time
Duty Cycle
Output Period Jitter
J
P
f
OUT
t
R
t
F
f
IN
= 5MHz to 50MHz
C
L
< 5pF
20% to 80% of V
DD
, f
OUT
= 80MHz,
f
IN
= 13MHz
80% to 20% of V
DD
, f
OUT
= 80MHz,
f
IN
= 13MHz
f
OUT
= 45MHz, f
IN
= 13MHz
f
OUT
= 45MHz, f
IN
= 13MHz
f
OUT
= 80MHz, f
IN
= 13MHz
f
OUT
= 197MHz, f
IN
= 13MHz
Soft Power-On Time
Hard Power-On Time
VCXO CLOCK
Crystal Frequency
Crystal Accuracy
Tuning Voltage Range
VCXO Tuning Range
TUNE Input Impedance
Output CLK Accuracy
Z
TUNE
V
TUNE
= 1.5V, C
1
= C
2
= 4pF
V
TUNE
V
TUNE
= 0 to 3V, C
1
= C
2
= 4pF
0
±150
±200
95
±50
t
PO2
t
PO1
f
XTL
PD
from low to high, f
OUT
= 45MHz,
f
IN
= 13MHz, see Figure 2
See Figure 2
44
4
133
200
1.5
1.3
50
14
22
13
1
15
27
±30
3
ms
ms
MHz
ppm
V
ppm
kΩ
ppm
ps
RMS
56
MHz
ns
ns
%
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX9491
Note 1:
All parameters are tested at T
A
= +25°C. Specifications over temperature are guaranteed by design and characterization.
Note 2:
Guaranteed by design and characterization; limits are set at ±6 sigma.
_______________________________________________________________________________________
3
Factory Programmable Single PLL
Clock Generator
MAX9491
Typical Operating Characteristics
(V
DD
= V
DDA
= +3.3V, T
A
= +25°C, f
IN
= 13MHz clock, C
L
= 10pF, 27MHz, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
MAX9491 toc01
RISE TIME vs. TEMPERATURE
MAX9491 toc02
FALL TIME vs. TEMPERATURE
f
IN
= 13MHz
f
OUT
= 45MHz
MAX9491 toc03
13
f
IN
= 13MHz
f
OUT
= 45MHz
2.2
f
IN
= 13MHz
f
OUT
= 45MHz
2.2
12
SUPPLY CURRENT (mA)
1.8
RISE TIME (ns)
1.8
FALL TIME (ns)
11
1.4
1.4
10
1.0
1.0
9
0.6
0.6
8
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.2
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.2
-40
-15
10
35
60
85
TEMPERATURE (°C)
JITTER vs. TEMPERATURE
MAX9491 toc04
JITTER vs. TEMPERATURE
MAX9491 toc05
JITTER vs. TEMPERATURE
f
IN
= 27MHz
f
OUT
= 197MHz
MAX9491 toc06
40
35
30
JITTER (ps)
f
IN
= 13MHz
f
OUT
= 45MHz
40
f
IN
= 13MHz
f
OUT
= 80MHz
40
32
30
JITTER (ps)
-40
-15
10
35
60
85
20
15
10
5
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
JITTER (ps)
25
24
20
16
8
10
0
TEMPERATURE (°C)
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
TYPICAL CLK_OUT WAVEFORM AT 45MHz
MAX9491 toc07
TYPICAL CLK_OUT WAVEFORM AT 80MHz
MAX9491 toc08
TYPICAL CLK_OUT WAVEFORM AT 197MHz
V
DD
= V
DDA
= 3.0V
MAX9491 toc09
V
DD
= V
DDA
= 3.0V
V
DD
= V
DDA
= 3.0V
CLK1
1V/div
CLK1
1V/div
CLK1
1V/div
4ns/div
4ns/div
4ns/div
4
_______________________________________________________________________________________
Factory Programmable Single PLL
Clock Generator
MAX9491
Typical Operating Characteristics (continued)
(V
DD
= V
DDA
= +3.3V, T
A
= +25°C, f
IN
= 13MHz clock, C
L
= 10pF, 27MHz, unless otherwise noted.)
VCXO ACCURACY vs. VCXO TUNING RANGE
MAX9491 toc10
DUTY CYCLE vs. OUTPUT FREQUENCY
f
IN
= 13MHz
MAX9491 toc11
300
200
VCXO ACCURACY (PP/M)
100
0
-100
-200
-300
0
f
IN
= 27MHz
f
OUT
= 45MHz
100
6pF
80
DUTY CYCLE (%)
60
4pF
5pF
40
20
0
0.5
1.0
1.5
2.0
2.5
3.0
45
50
55
60
65
70
75
80
VCXO TUNING RANGE (V)
FREQUENCY (MHz)
45MHz OUTPUT
10dB/REF = 0dBm
RBW = 3kHz
VBW = 3kHz
ATN = 20dB
CENTER = 45MHz
SPAN = 2MHz
MAX9491 toc12
80MHz OUTPUT
10dB/REF = 0dBm
RBW = 3kHz
VBW = 3kHz
ATN = 20dB
CENTER = 80MHz
SPAN = 2MHz
MAX9491 toc13
_______________________________________________________________________________________
5
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