DS1080L_V01 [MAXIM]
Spread-Spectrum Crystal Multiplier;
| 型号： | DS1080L_V01 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Spread-Spectrum Crystal Multiplier |
| 文件： | 总8页 (文件大小：217K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
DS1080L
Spread-Spectrum Crystal Multiplier
General Description
Features
The DS1080L is a low-jitter, crystal-based clock gener-
ator with an integrated phase-locked loop (PLL) to gen-
erate spread-spectrum clock outputs from 16MHz to
134MHz. The device is pin-programmable to select the
clock multiplier rate as well as the dither magnitude.
The DS1080L has a spread-spectrum disable mode
and a power-down mode to conserve power.
o Generates Spread-Spectrum Clocks from 16MHz
to 134MHz
o Selectable Clock Multiplier Rates of 1x, 2x, and 4x
o Center Spread-Spectrum Dithering
o Selectable Spread-Spectrum Modulation
Magnitudes of ±0.5%, ±1.0%, and ±1.5%
o Spread-Spectrum Disable Mode
o Low Cycle-to-Cycle Jitter
Applications
Automotive
Cable Modems
Cell Phones
Computer Peripherals
Copiers
o Power-Down Mode with High-Impedance Output
o Low Power Consumption
o 3.0V to 3.6V Single-Supply Operation
o -40°C to +125°C Temperature Operation
o Small 8-Lead µSOP Package
Infotainment
PCs
Printers
Pin Configuration
Ordering Information
PART
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
8 µSOP
DS1080LU+
DS1080LU/V+
DS1080LU/V+T
DS1080LU+T
TOP VIEW
8 µSOP
8 µSOP
+
8 µSOP
X1
GND
1
2
3
4
8
7
6
5
X2
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
T = Tape and reel.
V
DS1080L
CC
CMSEL
SMSEL
SSO
PDN
µSOP
For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
19-4997; Rev 5; 3/13
DS1080L
Spread-Spectrum Crystal Multiplier
ABSOLUTE MAXIMUM RATINGS
Voltage on V
Voltage on Any Lead Relative
to GND.................-0.3V to (V
Continuous Power Dissipation (T = +70°C)
Relative to GND...........................-0.3V to +4.3V
Operating Temperature Range .........................-40°C to +125°C
Storage Temperature Range.............................-55°C to +125°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
CC
+ 0.3V), not to exceed +4.3V
CC
A
µSOP (derate 4.5mW/°C above +70°C).......................362mW
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.
RECOMMENDED OPERATING CONDITIONS
(T = -40°C to +125°C, unless otherwise noted.)
A
PARAMETER
Supply Voltage
SYMBOL
CONDITIONS
MIN
3.0
TYP
MAX
UNITS
V
CC
(Note 1)
3.6
V
0.8 x
V
+
0.3
CC
Input Logic 1
Input Logic 0
V
V
V
IH
V
CC
V
-
0.2 x
V
GND
0.3
V
IL
CC
Input Logic Open
Input Leakage
I
I
0V < V < V (Note 2)
1
µA
µA
IF
IL
IN
CC
0V < V < V (Note 3)
80
IN
CC
f
< 67MHz
15
10
7
SSO
SSO Load
C
pF
67MHz ꢀ f
< 101MHz
SSO
SSO
101MHz ꢀ f
< 134MHz
SSO
Crystal or Clock Input
Frequency
f
16.0
40
33.4
MHz
IN
Crystal ESR
X
90
60
ꢁ
ESR
Clock Input Duty Cycle
F
%
INDC
Crystal Parallel Load
Capacitance
C
L
(Note 4)
18
pF
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +3.6V, T = -40°C to +125°C, unless otherwise noted.)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
15
UNITS
mA
Supply Current
I
C
= 15pF, SSO = 16MHz
SSO
CC1
Power-Down Current
Output Leakage (SSO)
I
PDN = GND, all input pins open
PDN = GND
200
+1
µA
CCQ
I
-1
µA
OZ
Low-Level Output Voltage
(SSO)
V
I
= 4mA
0.4
V
OL
OL
High-Level Output Voltage
(SSO)
V
I
= -4mA
2.4
V
OH
OH
Input Capacitance (X1/X2)
C
(Note 5)
5
pF
IN
2
Maxim Integrated
DS1080L
Spread-Spectrum Crystal Multiplier
AC ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0 to +3.6V, T = -40°C to +125°C, unless otherwise noted.)
A
PARAMETER
SYMBOL
CONDITIONS
Measured at V /2, CMSEL = 0 or open
MIN
40
TYP
MAX
60
UNITS
CC
SSO Duty Cycle
SSODC
%
Measured at V /2, CMSEL = 1
CC
30
70
Rise Time
Fall Time
t
(Note 6)
(Note 6)
1.6
1.6
ns
ns
R
t
F
f
= 16MHz, T = -40 to +85°C,
A
SSO
Peak Cycle-to-Cycle Jitter
Power-Up Time
t
75
ps
J
10,000 cycles (Note 5)
16MHz
20
11
t
t
PDN pin (Note 7)
ms
ns
POR
33.4MHz
Power-Down Time
Dither Rate
PDN pin (Notes 8 and 9)
100
PDN
f
(Note 9)
f /992
IN
DITHER
Note 1: All voltages referenced to ground.
Note 2: Maximum source/sink current applied to input to be considered an open. Typical voltage range between 0.4 x V
and 0.55
CC
x V
.
CC
Note 3: Applicable to pins CMSEL, SMSEL, and PDN.
Note 4: See information about C and C in the Applications Information section at the end of the data sheet.
L1
L2
Note 5: Not production tested.
Note 6: For 7pF load.
Note 7: Time between PDN deasserted to output active.
Note 8: Time between PDN asserted to output high impedance.
Note 9: Guaranteed by design.
Maxim Integrated
3
DS1080L
Spread-Spectrum Crystal Multiplier
Typical Operating Characteristics
(V
CC
= 3.3V, T = +25°C, unless otherwise noted.)
A
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
SUPPLY CURRENT vs. FREQUENCY
13
12
13
12
11
10
9
AT 16MHz
CMSEL = 1x
AT 16MHz
CMSEL = 1x
AT 16MHz
CMSEL = 1x
19
17
15
13
11
9
11
10
9
8
8
7
7
3.0
3.2
3.4
-40
10
60
110
16
21
26
31
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
FREQUENCY (MHz)
PDN SUPPLY CURRENT
vs. TEMPERATURE
DUTY CYCLE vs. TEMPERATURE
0.06
0.05
0.04
0.03
0.02
0.01
0
60
AT 16MHz
CMSEL = 1x
AT 16MHz
58
56
54
52
50
48
46
44
42
40
-40
10
60
110
-40
10
60
110
TEMPERATURE (°C)
TEMPERATURE (°C)
FREQUENCY SPECTRUM AT 133.3MHz
DUTY CYCLE vs. SUPPLY VOLTAGE
5
0
-5
60
58
56
54
52
50
48
46
44
42
40
NO ꢁDTHEꢂ
AT 16MHz
±1ꢀ ꢁDTHEꢂ
±±0.ꢀ ꢁDTHEꢂ
-10
-15
-20
-25
-30
-35
-40
-45
-50
-55
-60
-65
±ꢃꢀ
ꢁDTHEꢂ
AT 13303MHz
129.3
131.3
133.3
135.3
137.3
3.0
3.2
3.4
3.6
OUTPUT FREQUENCY (MHz)
SUPPLY VOLTAGE (V)
4
Maxim Integrated
DS1080L
Spread-Spectrum Crystal Multiplier
Pin Description
PIN
1
NAME
X1
FUNCTION
Crystal Drive/Clock Input. A crystal with the proper loading capacitors is connected across X1 and X2.
Instead of a crystal, a clock can be applied at the X1 input.
2
GND
Signal Ground
Clock Multiplier Select. Tri-level digital input.
0 = 1x
Open = 2x
1 = 4x
3
4
5
CMSEL
SMSEL
Spread-Spectrum Magnitude Select. Tri-level digital input.
0 = 0.5%
Open = 1.0%
1 = 1.5%
Power-Down/Spread-Spectrum Disable. Tri-level digital input.
0 = Power-Down/SSO Three-Stated
Open = Power-Up/Spread Spectrum Disabled
1 = Power-Up/Spread Spectrum Enabled
PDN
Spread-Spectrum Clock Multiplier Output. Outputs a 1x, 2x, or 4x spread-spectrum version of the crystal
or clock applied at the X1/X2 pins.
6
7
8
SSO
V
CC
Supply Voltage
Crystal Drive Output. A crystal with the proper loading capacitors is connected across X1 and X2.
If a clock is connected to X1, then X2 should be left open circuit.
X2
Block Diagram
V
CC
V
CC
f
IN
X1
X2
16MHz
TO
33.4MHz
f
= 16MHz
TO
134MHz
SSO
CRYSTAL
OSCILLATOR
1x/2x/4x CLOCK MULTIPLYING
PLL WITH SPREAD SPECTRUM
SSO
f
SSO
C
L2
C
L1
PDN
GND
CMSEL
SMSEL
CONFIGURATION DECODE
AND CONTROL
DS1080L
NOTE: SEE INFORMATION ABOUT C AND C IN THE APPLICATIONS INFORMATION SECTION AT THE END OF THE DATA SHEET.
L1
L2
Maxim Integrated
5
DS1080L
Spread-Spectrum Crystal Multiplier
Oscillator Input
Detailed Description
When driving the DS1080L using an external oscillator
clock, consider the input (X1) to be high impedance.
The DS1080L is a crystal multiplier with center spread-
spectrum capability. A 16MHz to 33.4MHz crystal is
connected to the X1 and X2 pins. Alternately, a 16MHz
to 33.4MHz clock can be applied to X1 in place of the
crystal. In such applications, X2 would be left open cir-
cuit. Using the CMSEL input, the user selects whether
the attached crystal or input clock is multiplied by 1, 2,
or 4. The DS1080L is capable of generating spread-
spectrum clocks from 16MHz to 134MHz.
Crystal Capacitor Selection
The load capacitors C and C are selected based
on the crystal specifications (from the data sheet of the
crystal used). The crystal parallel load capacitance is
calculated as follows:
L1
L2
C
C
L1
x C
L2
+ C
L2
L1
C
L
=
+ C
Equation1
Equation2
IN
The PLL can dither the output clock about its center fre-
quency at a user-selectable magnitude. Using the
SMSEL input, the user selects the dither magnitude.
The PDN input can be used to place the device into a
low-power standby mode where the SSO output is tri-
stated. If the PDN pin is open, the SSO output is active
but the spread-spectrum dithering is disabled. The
For the DS1080L use C = C = C .
LX
L1
L2
In this case, the equation then reduces to:
C
2
LX
C
L
=
+ C
IN
spread-spectrum dither rate is fixed at f / 992 to keep
IN
the dither rate above the audio frequency range. On
power-up, the output clock (SSO) remains three-stated
where C = C = C
L1
L2
LX.
until the PLL reaches a stable frequency (f
) and
SSO
Equation 2 is used to calculate the values of C and
L1
dither (f
).
DITHER
C
based on values on C and C noted in the data
L2
L IN
sheet electrical specifications.
Applications Information
Power-Supply Decoupling
To achieve best results, it is highly recommended that
a decoupling capacitor is used on the IC power-supply
pins. Typical values of decoupling capacitors are
0.001µF and 0.1µF. Use a high-quality, ceramic, sur-
face-mount capacitor, and mount it as close as possi-
Crystal Selection
The DS1080L requires a parallel resonating crystal
operating in the fundamental mode, with an ESR of less
than 90!. The crystal should be placed very close to
the device to minimize excessive loading due to para-
sitic capacitances.
ble to the V
and GND pins of the IC to minimize lead
CC
inductance.
DITHER CYCLE RATE = f = f /992
DITHER IN
+1.5%
+1.0%
+0.5%
f
0
-0.5%
-1.0%
-1.5%
t
Figure 1. Spread-Spectrum Frequency Modulation
6
Maxim Integrated
DS1080L
Spread-Spectrum Crystal Multiplier
Typical Operating Circuit
CRYSTAL
C
C
L2
L1
X1
GND
X2
V
1
2
3
4
8
7
6
5
CC
V
CC
DS1080L
DECOUPLING
CAPACITOR
CMSEL
SMSEL
SSO
PDN
f
SSO
V
CC
NOTE: IN THE ABOVE CONFIGURATION WITH PDN CONNECTED TO V , SMSEL CONNECTED TO GND
CC
AND CMSEL OPEN, THE DEVICE IS IN NORMAL OPERATION WITH 2x CLOCK MULTIPLICATION, AND
SPREAD-SPECTRUM MAGNITUDE OF 0.5%.
Layout Considerations
Package Information
As noted earlier, the crystal should be placed very
close to the device to minimize excessive loading due
to parasitic capacitances. Care should also be taken to
minimize loading on pins that could be open as a pro-
gramming option (SMSEL and CMSEL). Coupling on
inputs due to clocks should be minimized.
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character,
but the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
8 µSOP
U8+1
21-0036
90-0092
Maxim Integrated
7
DS1080L
Spread-Spectrum Crystal Multiplier
Revision History
REVISION REVISION
DESCRIPTION
PAGES
CHANGED
NUMBER
DATE
0
11/05
Initial release
Changed V
in the Recommended Operating Conditions table
—
from 0.7V x V
to 0.08V x V
and V
from 0.3 x V
to 0.2V x V
CC CC
IHMIN
CC
CC
ILMAX
1
2
3
4
3/06
10/09
10/11
5/12
2
Changed the part number in the Ordering Information table
1
1, 2, 7
3
Updated the Ordering Information table and Absolute Maximum Ratings section; added the
land pattern no. to the Package Information table
Clarified SSODC conditions and split limits based upon CMSEL input state
Updated the voltage ranges in the Absolute Maximum Ratings; changed the supply current
parameter from 13mA (max) to 15mA (max) in the DC Electrical Characteristics table;
5
3/13
2, 3, 4
changed the dither rate parameter from f /1024 to f /992 in the AC Electrical
IN
IN
Characteristics table; updated all graphs in the Typical Operating Characteristics section
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent
licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and
max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
8
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© 2013 Maxim Integrated Products, Inc.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
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