19-6068; Rev 1; 10/11
Spread-Spectrum Crystal Multiplier
General Description
The DS1080CL is a low-jitter, crystal-based clock gen-
erator with an integrated phase-locked loop (PLL) to
generate spread-spectrum clock outputs from 8MHz to
64MHz. The device is pin programmable to select the
clock multiplier rate as well as the dither magnitude.
The DS1080CL has a spread-spectrum disable mode
and a power-down mode to conserve power.
Features
♦
Generates Spread-Spectrum Clocks from 8MHz to
64MHz
♦
Selectable Clock Multiplier Rates of 1x, 2x, and 4x
♦
Center Spread-Spectrum Dithering
♦
Selectable Spread-Spectrum Modulation
Magnitudes of ±0.5%, ±1.0%, and ±1.5%
♦
Spread-Spectrum Disable Mode
♦
Low Cycle-to-Cycle Jitter
♦
Power-Down Mode with High-Impedance Output
♦
Low-Power Consumption
♦
3.0V to 3.6V Single-Supply Operation
♦
-40°C to +125°C Temperature Operation
♦
Small 8-Pin
µSOP
Package
DS1080CL
Applications
Automotive
Cable Modems
Cell Phones
Computer Peripherals
Copiers
Infotainment
PCs
Printers
Pin Configuration
TOP VIEW
+
X1
GND
CMSEL
SMSEL
1
2
3
4
8
X2
V
CC
SSO
PDN
Ordering Information
PART
DS1080CLU+
DS1080CLU+T
6
5
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
8 μSOP
8 μSOP
8 μSOP
DS1080CL
7
DS1080CLU/V+
DS1080CLU/V+T
+Denotes
a lead-free package.
/V denotes an automotive qualified part.
T = Tape and reel.
Typical Operating Circuit
CRYSTAL
C
L1
C
L2
X1
GND
CMSEL
SMSEL
1
2
3
4
8
X2
V
CC
SSO
PDN
V
CC
DECOUPLING
CAPACITOR
DS1080CL
7
6
5
f
SSO
V
CC
NOTE:
IN THE ABOVE CONFIGURATION WITH PDN CONNECTED TO V
CC
, SMSEL CONNECTED TO GND, AND CMSEL OPEN, THE DEVICE IS IN NORMAL
OPERATION WITH 2x CLOCK MULTIPLICATION AND A SPREAD-SPECTRUM MAGNITUDE OF
±0.5%.
________________________________________________________________
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.
Spread-Spectrum Crystal Multiplier
DS1080CL
ABSOLUTE MAXIMUM RATINGS
Voltage Range on V
CC
Relative to GND .............-0.5V to +3.63V
Voltage Range on Any Pin Relative
to GND ...............-0.5V to (V
CC
+ 0.5V), not to exceed +3.63V
Continuous Power Dissipation (T
A
= +75°C)
µSOP (derate 4.5mW/°C above +70°C).......................362mW
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
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
A
= -40°C to +125°C, unless otherwise noted.)
PARAMETER
Supply Voltage
Input Logic 1
Input Logic 0
Input Logic Open
Input Leakage
SSO Load
Crystal or Clock Input
Frequency
Crystal ESR
Clock Input Duty Cycle
Crystal Parallel Load
Capacitance
SYMBOL
V
CC
V
IH
V
IL
I
IF
I
IL
C
SSO
f
IN
X
ESR
F
INDC
C
L
(Note 4)
40
8
0V < V
IN
< V
CC
(Note 2)
0V < V
IN
< V
CC
(Note 3)
(Note 1)
CONDITIONS
MIN
3.0
0.8 x
V
CC
V
GND
-
0.3
TYP
MAX
3.6
V
CC
+
0.3
0.2 x
V
CC
±1
±80
15
16
90
60
18
%
pF
UNITS
V
V
V
μA
μA
pF
MHz
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +3.6V, T
A
= -40°C to +125°C, unless otherwise noted.)
PARAMETER
Supply Current
Power-Down Current
Output Leakage (SSO)
Low-Level Output Voltage
(SSO)
High-Level Output Voltage
(SSO)
Input Capacitance (X1/X2)
SYMBOL
I
CC1
I
CCQ
I
OZ
V
OL
V
OH
C
IN
CONDITIONS
C
SSO
= 15pF, f
SSO
= 8MHz
PDN
= GND, all input pins open
PDN
= GND
I
OL
= 4mA
I
OH
= -4mA
(Note 5)
2.4
5
-1
MIN
TYP
7
MAX
12
200
+1
0.4
UNITS
mA
μA
μA
V
V
pF
2
_______________________________________________________________________________________
Spread-Spectrum Crystal Multiplier
AC ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0 to +3.6V, T
A
= -40°C to +125°C, unless otherwise noted.)
PARAMETER
SSO Duty Cycle
Rise Time
Fall Time
Peak Cycle-to-Cycle Jitter
Power-Up Time
Power-Down Time
Dither Rate
SYMBOL
SSODC
t
R
t
F
t
J
t
POR
t
PDN
f
DITHER
(Note 6)
(Note 6)
f
SSO
= 8MHz, T
A
= -40°C to +85°C,
10,000 cycles (Note 5)
PDN
pin (Note 7)
PDN
pin (Notes 8, 9)
f
IN
/512
8MHz
16MHz
CONDITIONS
Measured at V
CC
/2
MIN
45
1.6
1.6
75
20
10
100
TYP
MAX
55
UNITS
%
ns
ns
ps
ms
ns
DS1080CL
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
All voltages referenced to ground.
Maximum source/sink current applied to input to be considered an open.
Applicable to pins CMSEL, SMSEL, and
PDN.
See information about C
L1
and C
L2
in the
Applications Information
section.
Not production tested.
For 15pF load.
Time between
PDN
deasserted to output active.
Time between
PDN
asserted to output high impedance.
Guaranteed by design.
_______________________________________________________________________________________
3
Spread-Spectrum Crystal Multiplier
DS1080CL
Typical Operating Characteristics
(V
CC
= 3.3V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
DS1080CL toc01
SUPPLY CURRENT vs. TEMPRATURE
CMSEL = 4x
DS1080CL toc02
SUPPLY CURRENT vs. FREQUENCY
DS1080CL toc03
12
CMSEL = 4x
10
SUPPLY CURRENT (mA)
8
6
CMSEL = 1x
4
2
f
IN
= 8MHz
0
2.95
3.05
3.15
3.25
3.35
3.45
3.55
CMSEL = 2x
14
12
SUPPLY CURRENT (mA)
10
8
6
4
2
f
IN
= 8MHz
0
CMSEL = 1x
CMSEL = 2x
12
10
SUPPLY CURRENT (mA)
8
6
4
2
0
V
CC
= 3.0V
V
CC
= 3.6V
3.65
-40
-15
10
35
60
85
110
8
16
24
32
40
48
56
64
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
FREQUENCY (MHz)
DUTY CYCLE vs. TEMPERATURE
DS1080CL toc04
DUTY CYCLE vs. SUPPLY VOLTAGE
54
53
DUTY CYCLE (%)
52
51
50
49
48
47
46
45
CMSEL = 1x
CMSEL = 2x
f
IN
= 8MHz
CMSEL = 4x
DS1080CL toc05
FREQUENCY SPECTRUM AT 64MHz
-10
-20
ATTENUATION (dB)
-30
-40
-50
-60
-70
-80
-90
-14.1dB
-11dB
-15.6dB
DS1080CL toc06
55
54
53
DUTY CYCLE (%)
52
51
50
49
48
47
46
45
f
IN
= 8MHz
CMSEL = 4x
55
0
CMSEL = 2x
CMSEL = 1x
-40
10
60
110
3.0
3.1
3.2
3.3
3.4
3.5
3.6
61
62
63
64
65
66
67
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
FREQUENCY (MHz)
4
_______________________________________________________________________________________
Spread-Spectrum Crystal Multiplier
Pin Description
PIN
1
2
NAME
X1
GND
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.
Signal Ground
Clock Multiplier Select. Trilevel digital input.
0 = 1x
Open = 2x
1 = 4x
Spread-Spectrum Magnitude Select. Trilevel digital input.
0 = ±0.5%
Open = ±1.0%
1 = ±1.5%
Power-Down/Spread-Spectrum Disable. Trilevel digital input.
0 = Power-Down/SSO High Impedance
Open = Power-Up/Spread Spectrum Disabled
1 = Power-Up/Spread Spectrum Enabled
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.
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.
DS1080CL
3
CMSEL
4
SMSEL
5
PDN
6
7
8
SSO
V
CC
X2
Block Diagram
V
CC
X1
8MHz
TO
16MHz
C
L1
C
L2
PDN
CMSEL
SMSEL
CONFIGURATION DECODE
AND CONTROL
X2
f
IN
CRYSTAL
OSCILLATOR
1x/2x/4x CLOCK MULTIPLYING
PLL WITH SPREAD SPECTRUM
V
CC
SSO
f
SSO
f
SSO
= 8MHz
TO
64MHz
GND
DS1080CL
NOTE:
SEE INFORMATION ABOUT C
L1
AND C
L2
IN THE
APPLICATIONS INFORMATION
SECTION.
_______________________________________________________________________________________
5
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