MAXIM MAX9491ETP

19-3942; Rev 0; 1/06
Factory-Programmable, Single PLL
Clock Generator
The MAX9491 multipurpose clock generator is ideal for
communication applications. It offers a factory-programmable 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 voltage-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 specified 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
Ordering Information
Applications
Telecommunications
PART
Data Networking Systems
Home Entertainment Centers
SOHO
TEMP RANGE
PINPACKAGE
MAX9491ETP
-40°C to +85°C
20 TQFN-EP**
MAX9491EUD*
-40°C to +85°C
14 TSSOP
PKG
CODE
T2055-5
U14-2
*Future product—contact factory for availability.
**EP = Exposed pad.
VDD
I.C.
VDD
VDD
GND
TOP VIEW
PD
Pin Configurations
15
14
13
12
11
16
X2
17
X1
18
TOP VIEW
GND
X1 1
14 X2
9
I.C.
I.C. 2
13 PD
8
I.C.
I.C. 3
12 VDD
10
MAX9491
20
6
I.C.
TUNE 5
1
2
3
4
5
CLK_OUT
I.C.
GND
I.C.
VDDA
7
AGND
19
TUNE
I.C.
VDD 4
MAX9491
11 GND
10 I.C.
GND 6
9
GND
CLK_OUT 7
8
I.C.
TSSOP
TQFN (5mm x 5mm)
________________________________________________________________ Maxim Integrated Products
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.
1
MAX9491
General Description
MAX9491
Factory Programmable Single PLL
Clock Generator
ABSOLUTE MAXIMUM RATINGS
VDD to GND ...........................................................-0.3V to +4.0V
VDDA to AGND ......................................................-0.3V to +4.0V
All Other Pins to GND ..................................-0.3V to VDD + 0.3V
Short-Circuit Duration
(all LVCMOS outputs)..............................................Continuous
ESD Protection (Human Body Model)..................................±2kV
Continuous Power Dissipation (TA = +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
(VDD = VDDA = +3.0V to +3.6V and TA = -40°C to +85°C. Typical values at VDD = VDDA = 3.3V, TA = +25°C, unless otherwise noted.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
LVCMOS INPUTS (PD, X1 as a reference INPUT CLK)
Input High Level
VIH
2.0
VDD
V
Input Low Level
VIL
0
0.8
V
High-Level Input Current
IIH
VIN = VDD
Low-Level Input Current
IIL
VIN = 0
20
µA
-20
µA
VDD 0.6
V
CLOCK OUTPUT (CLK_OUT)
Output High Level
VOH
IOH = -4mA
Output Low Level
VOL
IOL = 4mA
0.4
V
POWER SUPPLIES
Digital Power-Supply Voltage
VDD
3.0
3.6
V
Analog Power-Supply Voltage
VDDA
3.0
3.6
V
Total Current for Digital and
Analog Supplies
IDC
fOUT = 45MHz, no load
fIN = 13MHz
10
mA
Power-Down Current
IDC2
PD = low
60
µA
2
_______________________________________________________________________________________
Factory Programmable Single PLL
Clock Generator
(VDD = VDDA = +3.0V to +3.6V, CL = 10pF and TA = -40°C to +85°C. Typical values are at VDD = VDDA = 3.3V, TA = +25°C, unless
otherwise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OUTPUT CLOCK (CLK_OUT)
Minimum Frequency Range
Maximum Frequency Range
fOUT
fIN = 5MHz to 50MHz
CL < 5pF
4
133
MHz
200
Clock Rise Time
tR
20% to 80% of VDD, fOUT = 80MHz,
fIN = 13MHz
1.5
ns
Clock Fall Time
tF
80% to 20% of VDD, fOUT = 80MHz,
fIN = 13MHz
1.3
ns
Duty Cycle
fOUT = 45MHz, fIN = 13MHz
Output Period Jitter
JP
44
50
fOUT = 45MHz, fIN = 13MHz
14
fOUT = 80MHz, fIN = 13MHz
22
fOUT = 197MHz, fIN = 13MHz
13
56
%
ps
RMS
Soft Power-On Time
tPO2
PD from low to high, fOUT = 45MHz,
fIN = 13MHz, see Figure 2
1
ms
Hard Power-On Time
tPO1
See Figure 2
15
ms
VCXO CLOCK
Crystal Frequency
fXTL
27
MHz
±30
ppm
Crystal Accuracy
Tuning Voltage Range
VTUNE
VCXO Tuning Range
TUNE Input Impedance
Output CLK Accuracy
0
VTUNE = 0 to 3V, C1 = C2 = 4pF
ZTUNE
VTUNE = 1.5V, C1 = C2 = 4pF
±150
3
±200
V
ppm
95
kΩ
±50
ppm
Note 1: All parameters are tested at TA = +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
MAX9491
AC ELECTRICAL CHARACTERISTICS
Typical Operating Characteristics
(VDD = VDDA = +3.3V, TA = +25°C, fIN = 13MHz clock, CL = 10pF, 27MHz, unless otherwise noted.)
RISE TIME vs. TEMPERATURE
9
1.4
1.0
10
35
60
85
-15
TEMPERATURE (°C)
10
35
60
85
-40
MAX9491 toc04
JITTER (ps)
25
20
15
10
fIN = 13MHz
fOUT = 80MHz
32
30
35
60
85
JITTER vs. TEMPERATURE
40
fIN = 27MHz
fOUT = 197MHz
30
24
JITTER (ps)
fIN = 13MHz
fOUT = 45MHz
10
TEMPERATURE (°C)
JITTER vs. TEMPERATURE
40
MAX9491 toc03
-15
TEMPERATURE (°C)
JITTER vs. TEMPERATURE
35
1.0
0.2
-40
MAX9491 toc05
-15
1.4
0.6
0.2
-40
40
1.8
0.6
8
fIN = 13MHz
fOUT = 45MHz
MAX9491 toc06
10
FALL TIME vs. TEMPERATURE
2.2
FALL TIME (ns)
11
fIN = 13MHz
fOUT = 45MHz
1.8
RISE TIME (ns)
12
SUPPLY CURRENT (mA)
2.2
MAX9491 toc01
fIN = 13MHz
fOUT = 45MHz
MAX9491 toc02
SUPPLY CURRENT vs. TEMPERATURE
13
JITTER (ps)
16
20
10
8
5
0
0
-40
-15
10
35
60
85
0
-40
-15
10
35
85
-40
-15
10
35
60
85
TYPICAL CLK_OUT WAVEFORM AT 45MHz
TYPICAL CLK_OUT WAVEFORM AT 80MHz
TYPICAL CLK_OUT WAVEFORM AT 197MHz
VDD = VDDA = 3.0V
CLK1
1V/div
4ns/div
MAX9491 toc09
TEMPERATURE (°C)
MAX9491 toc08
TEMPERATURE (°C)
VDD = VDDA = 3.0V
4
60
TEMPERATURE (°C)
MAX9491 toc07
MAX9491
Factory Programmable Single PLL
Clock Generator
VDD = VDDA = 3.0V
CLK1
1V/div
CLK1
1V/div
4ns/div
4ns/div
_______________________________________________________________________________________
Factory Programmable Single PLL
Clock Generator
6pF
100
4pF
0
5pF
-100
fIN = 13MHz
80
DUTY CYCLE (%)
60
40
20
-200
-300
0
0.5
1.0
1.5
2.0
2.5
3.0
45
50
55
60
65
70
VCXO TUNING RANGE (V)
FREQUENCY (MHz)
45MHz OUTPUT
80MHz OUTPUT
10dB/REF = 0dBm
RBW = 3kHz
VBW = 3kHz
ATN = 20dB
CENTER = 45MHz
SPAN = 2MHz
MAX9491 toc12
0
10dB/REF = 0dBm
RBW = 3kHz
VBW = 3kHz
ATN = 20dB
CENTER = 80MHz
SPAN = 2MHz
75
80
MAX9491 toc13
VCXO ACCURACY (PP/M)
200
DUTY CYCLE vs. OUTPUT FREQUENCY
100
MAX9491 toc10
fIN = 27MHz
fOUT = 45MHz
MAX9491 toc11
VCXO ACCURACY vs. VCXO TUNING RANGE
300
_______________________________________________________________________________________
5
MAX9491
Typical Operating Characteristics (continued)
(VDD = VDDA = +3.3V, TA = +25°C, fIN = 13MHz clock, CL = 10pF, 27MHz, unless otherwise noted.)
Factory Programmable Single PLL
Clock Generator
MAX9491
Typical Operating Circuit/Block Diagram
+3.3V
+3.3V
0.1µF
0.1µF x 3
VDD
VDDA
X1
OR REFERENCE
INPUT
VDD
MAX9491
C1
VDD
VCXO
C2
X2
PLL
CLK_OUT
TUNE
AGND
OTP
PD
GND
Pin Description
PIN
NAME
FUNCTION
TQFN
TSSOP
1
5
2
3
4, 10, 11
6, 9, 11
GND
5
7
CLK_OUT
6–9, 14, 19, 20
2, 3, 8, 10
I.C.
12, 13, 16
4, 12
VDD
Power Supply. Bypass to GND with a 0.1µF capacitor.
TUNE
VCXO Tune Voltage Input. If using a reference clock input or VCXO is not used,
connect TUNE to VDD.
—
VDDA
Analog Power Supply. Bypass to GND with a 0.1µF capacitor.
—
AGND
Analog Ground
Ground
Output Clock. Internally pulled down.
Internally Connected. Leave unconnected for normal operation.
15
13
PD
Active-Low Power-Down Input. Pull high for normal operation. Drive PD low to place
MAX9491 in power-down mode. Internally pulled down.
17
14
X2
Crystal Connection 2. Leave unconnected if using a reference clock.
18
1
X1
Crystal Connection 1 or Reference Clock Input
EP
—
EP
Exposed Paddle (TQFN Only). Connect EP to GND or leave unconnected.
Detailed Description
The MAX9491 features a programmable fractional-N
PLL, so frequencies between 4MHz to 200MHz can be
generated. The device provides a buffered PLL clock
output. The crystal input frequency can be between
5MHz and 35MHz, and the clock input between 5MHz
and 50MHz. The internal VCXO has a fine-tuning range
of ±200ppm.
Power-Down
Driving PD low places the MAX9491 in power-down
mode. PD then sets CLK_OUT to high impedance and
6
shuts down the PLL. CLK_OUT has an 80kΩ (typ) internal pulldown resistor.
Voltage-Controlled Crystal Oscillator
(VCXO)
The MAX9491’s internal VCXO produces a reference
clock for the PLL used to generate the CLK_OUT. The
oscillator uses a crystal as the base frequency reference and has a voltage-controlled tuning input for micro
adjustment in a ±200ppm range. The tuning voltage,
VTUNE, can vary from 0 to 3V as shown in Figure 1. The
crystal should be AT-cut and oscillate on its fundamental mode with ±30ppm. The crystal shunt capacitor
_______________________________________________________________________________________
Factory Programmable Single PLL
Clock Generator
with an internal POR signal and can be disabled by PD.
When VCXO is not used, connect TUNE to VDD.
Applications Information
Using an Input Clock as the Reference
When an input clock is used as the reference, connect
the input clock to X1, leave X2 unconnected, and connect
TUNE to VDD.
27.0405
Crystal Selection
VCXO OUTPUT FREQUENCY
(MHz)
+150ppm
27.00
-150ppm
26.99595
3V
0
VTUNE
When using a crystal with the MAX9491’s internal oscillator, connect the crystal to X1 and X2. Choose an ATcut crystal that oscillates on its fundamental mode with
±30ppm and loading capacitance less than 14pF. To
achieve a wide VCXO tuning range, select a crystal
with motional capacitance greater than 7fF and connect 6pF or less shunt capacitors at both X1 and X2 to
ground. When the VCXO is used as an oscillator, select
both shunt capacitors to approximately 13pF. The optimal shunt capacitors for achieving minimum frequency
offset can be determined experimentally.
Figure 1. VCXO Tuning Range for a 27MHz Crystal
VDD
2.2V
t
CLK_IN
PD
CLK_OUT
tPO1
tPO2
Figure 2. PLL Settling Time
_______________________________________________________________________________________
7
MAX9491
should be less than 10pF, including board parasitic
capacitance. To achieve up to ±200ppm pullability, make
sure the crystal-loading capacitance is less than 14pF.
The VCXO is a free-running oscillator. It starts oscillating
MAX9491
Factory Programmable Single PLL
Clock Generator
Board Layout Considerations and
Bypassing
The MAX9491’s high-frequency oscillator requires
proper layout to ensure stability. For best performance,
place components as close as possible to the device.
Digital or AC transient signals on GND can create noise
at the clock output. Return GND to the highest quality
ground available. Bypass each VDD and VDDA with a
0.1µF capacitor, placed as close as possible to the
device. Careful PC board ground layout minimizes
crosstalk between the output and digital inputs.
8
Chip Information
PROCESS: CMOS
_______________________________________________________________________________________
Factory Programmable Single PLL
Clock Generator
TSSOP4.40mm.EPS
PACKAGE OUTLINE, TSSOP 4.40mm BODY
21-0066
G
1
1
_______________________________________________________________________________________
9
MAX9491
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
QFN THIN.EPS
MAX9491
Factory Programmable Single PLL
Clock Generator
D2
D
MARKING
b
CL
0.10 M C A B
D2/2
D/2
k
L
AAAAA
E/2
E2/2
CL
(NE-1) X e
E
DETAIL A
PIN # 1
I.D.
e/2
E2
PIN # 1 I.D.
0.35x45°
e
(ND-1) X e
DETAIL B
e
L1
L
CL
CL
L
L
e
e
0.10 C
A
C
0.08 C
A1 A3
PACKAGE OUTLINE,
16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm
-DRAWING NOT TO SCALE-
10
21-0140
______________________________________________________________________________________
I
1
2
Factory Programmable Single PLL
Clock Generator
COMMON DIMENSIONS
EXPOSED PAD VARIATIONS
PKG.
16L 5x5
20L 5x5
28L 5x5
32L 5x5
40L 5x5
SYMBOL MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX.
A
A1
A3
b
D
E
e
PKG.
CODES
0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80
0
0.02 0.05
0
0.02 0.05
0
0.02 0.05
0
0.02 0.05
0
T1655-2
T1655-3
T1655N-1
T2055-3
D2
3.00
3.00
3.00
3.00
3.00
T2055-4
T2055-5
3.15
T2855-3
3.15
T2855-4
2.60
T2855-5
2.60
3.15
T2855-6
T2855-7
2.60
T2855-8
3.15
T2855N-1 3.15
T3255-3
3.00
T3255-4
3.00
T3255-5
3.00
T3255N-1 3.00
T4055-1
3.20
0.02 0.05
0.20 REF.
0.20 REF.
0.20 REF.
0.20 REF.
0.20 REF.
0.25 0.30 0.35 0.25 0.30 0.35 0.20 0.25 0.30 0.20 0.25 0.30 0.15 0.20 0.25
4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10
4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10
0.65 BSC.
0.50 BSC.
0.40 BSC.
0.80 BSC.
0.50 BSC.
- 0.25 - 0.25 - 0.25 0.35 0.45
0.25 - 0.25 0.30 0.40 0.50 0.45 0.55 0.65 0.45 0.55 0.65 0.30 0.40 0.50 0.40 0.50 0.60
L1
- 0.30 0.40 0.50
40
16
N
20
28
32
ND
10
4
5
7
8
4
10
5
7
8
NE
WHHB
----WHHC
WHHD-1
WHHD-2
JEDEC
k
L
NOTES:
1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994.
2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES.
3. N IS THE TOTAL NUMBER OF TERMINALS.
L
E2
exceptions
MIN. NOM. MAX. MIN. NOM. MAX. ±0.15
3.10
3.10
3.10
3.10
3.10
3.25
3.25
2.70
2.70
3.25
2.70
3.25
3.25
3.10
3.10
3.10
3.10
3.30
3.20
3.20
3.20
3.20
3.20
3.35
3.35
2.80
2.80
3.35
2.80
3.35
3.35
3.20
3.20
3.20
3.20
3.40
3.00
3.00
3.00
3.00
3.00
3.15
3.15
2.60
2.60
3.15
2.60
3.15
3.15
33.00
33.00
3.00
3.00
3.20
3.10
3.10
3.10
3.10
3.10
3.25
3.25
2.70
2.70
3.25
2.70
3.25
3.25
3.10
3.10
3.10
3.10
3.30
3.20
3.20
3.20
3.20
3.20
3.35
3.35
2.80
2.80
3.35
2.80
3.35
3.35
3.20
3.20
3.20
3.20
3.40
**
**
**
**
**
0.40
**
**
**
**
**
0.40
**
**
**
**
**
**
DOWN
BONDS
ALLOWED
YES
NO
NO
YES
NO
YES
YES
YES
NO
NO
YES
YES
NO
YES
NO
YES
NO
YES
** SEE COMMON DIMENSIONS TABLE
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL
CONFORM TO JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE
OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE TERMINAL #1
IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE.
5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN
0.25 mm AND 0.30 mm FROM TERMINAL TIP.
6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY.
7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION.
8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS.
9. DRAWING CONFORMS TO JEDEC MO220, EXCEPT EXPOSED PAD DIMENSION FOR
T2855-3 AND T2855-6.
10. WARPAGE SHALL NOT EXCEED 0.10 mm.
11. MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY.
12. NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY.
13. LEAD CENTERLINES TO BE AT TRUE POSITION AS DEFINED BY BASIC DIMENSION "e", ±0.05.
PACKAGE OUTLINE,
16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm
21-0140
-DRAWING NOT TO SCALE-
I
2
2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11
© 2006 Maxim Integrated Products
Springer
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
MAX9491
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)