MK1726-08STR [IDT]
Clock Generator, 32MHz, CMOS, PDSO8, 0.150 INCH, SOIC-8;
| 型号： | MK1726-08STR |
| 厂家： | 
INTEGRATED DEVICE TECHNOLOGY |
| 描述： | Clock Generator, 32MHz, CMOS, PDSO8, 0.150 INCH, SOIC-8 时钟 光电二极管 外围集成电路 晶体 |
| 文件： | 总8页 (文件大小：143K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
DATASHEET
SPREAD SPECTRUM CLOCK GENERATOR
MK1726-08
Description
Features
The MK1726-08 generates a low EMI output clock and a
reference clock from a clock or crystal input. The part is
designed to lower EMI through the application of spreading
a clock. Using IDT’ proprietary mix of analog and digital
Phase-Locked Loop (PLL) technology, the device spreads
the frequency spectrum of the output, reducing the
frequency amplitude peaks by several dB depending on
spread range. The MK1726-08 offers a range of down
spread from a high speed clock or crystal input. The
MK1726-08 generates one modulated (SSCLK) and
unmodulated (REFCLK) clock and is compatible with
Cypress CY25819. The modulated clock is controlled by
the select pin, and the unmodulated clock has the same
frequency as the input clock or crystal.
• Packaged in 8-pin SOIC
• Available in Pb (lead) free package
• Input frequency range 16- 32 MHz
• Provides modulated and unmodulated clocks
• Accepts a clock or crystal input
• Provides down spread modulation
• Provides power down function
• Reduce electromagnetic interference (EMI) by
8-16 db
• Operating voltage of 3.3 V
• Advanced, low-power CMOS process
NOTE: EOL for non-green parts to occur on 5/13/10
per PDN U-09-01
Block Diagram
VDD
PD
S0
PLL Clock
Synthesis and
Spread
Spectrum
Circuitry
REFCLK
SSCLK
X1/CLK
Clock Buffer/
Crystal
Ocsillator
X2
External caps required for
with crystal for accurate
tuning of the clock
GND
IDT™ SPREAD SPECTRUM CLOCK GENERATOR
1
MK1726-08
REV C 121809
MK1726-08
SPREAD SPECTRUM CLOCK GENERATOR
SSCG
Pin Assignment
Spread Percentage Select Table
S0
Spread
Spread
Direction
Percentage (%)
X1/ICLK
GND
8
7
6
5
1
2
3
4
X2
0
1
Down
Down
Down
-1.8
-2.5
-0.6
VDD
S0
M
PD
SSCLK
REFCLK
8 pi n (150mi l) SOIC
0 = connect to GND
M= unconnected
1 = connect directly to VDD
* Default has internal pull up resitor to VDD
Pin Descriptions
Pin
Pin
Pin Type
Pin Description
Number
Name
1
2
3
4
5
X1/ICLK
GND
Input
Connect to 16-32 MHz crystal or clock.
Power Connect to ground.
Input Select spread percentage per table above. Internal pull-up.
Output Spread spectrum clock output per table above.
S0
SSCLK
REFCLK Power CMOS level clock output matches the nominal frequency of the input crystal or
clock.
6
PD
Input
Power down tri-state. This pin powers down entire chip and tri-state the outputs
when low. Internal pull-up.
7
8
VDD
X2
Power Connect to 3.3 V.
Input Connect to 16-32 MHz crystal or leave unconnected.
IDT™ SPREAD SPECTRUM CLOCK GENERATOR
2
MK1726-08
REV C 121809
MK1726-08
SPREAD SPECTRUM CLOCK GENERATOR
SSCG
is given by the following equation:
External Components
Crystal caps (pF) = (C - 6) x 2
The MK1726-08 requires a minimum number of external
components for proper operation.
L
In the equation, C is the crystal load capacitance. So, for a
crystal with a 16 pF load capacitance, two 20 pF [(16-6) x 2]
capacitors should be used.
L
Decoupling Capacitor
A decoupling capacitor of 0.01µF must be connected
between VDD and GND, as close to these pins as possible.
For optimum device performance, the decoupling capacitor
should be mounted on the component side of the PCB.
Avoid the use of vias in the decoupling circuit.
Spread Spectrum Profile
The MK1726-08 low EMI clock generator uses an optimized
frequency slew rate algorithm to facilitate down stream
tracking of zero delay buffers and other PLL devices. The
frequency modulation amplitude is constant with variations
of the input frequency.
Series Termination Resistor
When the PCB trace between the clock output and the load
is over 1 inch, series termination should be used. To series
terminate a 50Ωtrace (a commonly used trace impedance)
place a 33Ωresistor in series with the clock line, as close to
the clock output pin as possible. The nominal impedance of
the clock output is 20Ω.
Modulation Rate
PCB Layout Recommendations
For optimum device performance and lowest output phase
noise, the following guidelines should be observed.
1) The 0.01µF decoupling capacitor should be mounted on
the component side of the board as close to the VDD pin as
possible. No vias should be used between the decoupling
capacitor and VDD pin. The PCB trace to VDD pin should
be kept as short as possible, as should the PCB trace to the
ground via.
T i m e
2) To minimize EMI, the 33Ω series termination resistor (if
needed) should be placed close to the clock output.
3) An optimum layout is one with all components on the
same side of the board, minimizing vias through other signal
layers. Other signal traces should be routed away from the
MK1726-08. This includes signal traces just underneath the
device, or on layers adjacent to the ground plane layer used
by the device.
Crystal Information
The crystal used should be a fundamental mode (do not use
third overtone), parallel resonant. Crystal capacitors should
be connected from pins X1 to ground and X2 to ground to
optimize the initial accuracy. The value of these capacitors
IDT™ SPREAD SPECTRUM CLOCK GENERATOR
3
MK1726-08
REV C 121809
MK1726-08
SPREAD SPECTRUM CLOCK GENERATOR
SSCG
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the MK1726-08. These ratings, which are
standard values for IDT commercially rated parts, are stress ratings only. Functional operation of the device at these
or any other conditions above those indicated in the operational sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for extended periods can affect product reliability. Electrical
parameters are guaranteed only over the recommended operating temperature range.
Item
Rating
Supply Voltage, VDD
All Inputs and Outputs
7 V
-0.5 V to VDD+0.5 V
0 to +70° C
-65 to +150° C
125°C
Ambient Operating Temperature
Storage Temperature
Junction Temperature
Soldering Temperature
260°C
Recommended Operation Conditions
Parameter
Min.
Typ.
Max.
+70
Units
° C
Ambient Operating Temperature
Power Supply Voltage (measured in respect to GND)
0
+2.97
3.63
V
DC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V +10%, Ambient Temperature 0 to +70°C
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Power Supply Range
Input High Voltage
Input Middle Voltage
Input Low Voltage
Output High Voltage
V
V
V
V
2.97
3.3
3.63
V
V
V
V
V
DD
S0 Input
0.85 V
0.40 V
0.0
V
V
DD
INH
INM
INL
DD
DD
DD
S0 Input
S0 Input
0.50 V
0.0
0.60 V
0.15 V
DD
DD
DD
V
I
=4 ma, SSCLK
2.4
OH1
OH
and REFCLK
Output High Voltage
V
I
=6 ma, SSCLK
2.0
V
OH2
OH
and REFCLK
Output Low Voltage
Output Low Voltage
Power Supply Current
Power Supply Current
V
I
I
=4 ma, SSCLK
=10 ma, SSCLK
=32 MHz, no load
0.4
1.2
V
V
OL1
OL
OL
V
OL2
I
I
F
19.0
150
23.0
250
mA
uA
DD2
DD3
IN
PD = GND
IDT™ SPREAD SPECTRUM CLOCK GENERATOR
4
MK1726-08
REV C 121809
MK1726-08
SPREAD SPECTRUM CLOCK GENERATOR
SSCG
Parameter
Symbol
Conditions
Min.
Typ.
5
Max.
Units
pF
Input Capacitance
C
IN
clock output
impedance
20
ohms
Internal pull-up
resistor
R
SEL
360
kΩ
PU
AC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V +10%, Ambient Temperature 0 to +70° C
Parameter
Input Clock Frequency
Output Clock Frequency
Clock Rise Time
Symbol
Conditions
Min.
16
Typ. Max. Units
32
32
MHz
MHz
ns
16
trise1
tfall1
SSCLK and REFCLK,
0.4 V to 2.4 V
2.0
3.0
3.0
4.0
Clock Fall Time
SSCLK and REFCLK,
0.4 V to 2.4 V
2.0
4.0
ns
Input Clock Duty Cycle
Output Clock Duty Cycle
X
20
45
50
50
80
55
%
%
1
SSCLK and REFCLK
@1.5V
Cycle-to-Cycle Jitter
SSCLK,
Fin=21MHz,
Fout=21MHz
250
275
350
375
ps
ps
dB
Cycle-to-Cycle Jitter
REFCLK,
Fin=21MHz,
Fout=21MHz
EMI Peak Frequency Reduction
8 to 16
Thermal Characteristics
Parameter
Symbol
Conditions
Min.
Typ. Max. Units
Thermal Resistance Junction to
Ambient
θ
Still air
110
100
80
° C/W
° C/W
° C/W
° C/W
JA
JA
JA
JC
θ
θ
θ
1 m/s air flow
3 m/s air flow
Thermal Resistance Junction to Case
35
IDT™ SPREAD SPECTRUM CLOCK GENERATOR
5
MK1726-08
REV C 121809
MK1726-08
SPREAD SPECTRUM CLOCK GENERATOR
SSCG
Marking Diagram
8
5
MK172608
######
YYWW
1
4
Notes:
1. ###### is the lot code.
2. YYWW is the last two digits of the year, and the week number that the part was assembled.
Marking Diagram (Pb free)
8
5
MK17268L
######
YYWW
1
4
Notes:
1. ###### is the lot code.
2. YYWW is the last two digits of the year, and the week number that the part was assembled.
3. “L” designates Pb (lead) free package.
IDT™ SPREAD SPECTRUM CLOCK GENERATOR
6
MK1726-08
REV C 121809
MK1726-08
SPREAD SPECTRUM CLOCK GENERATOR
SSCG
Package Outline and Package Dimensions (8 pin SOIC, 150 Mil. Narrow Body)
Package dimensions are kept current with JEDEC Publication No. 95
Millimeters
Inches
Min Max
0.0532 0.0688
0.0040 0.0098
Symbol
Min
Max
1.75
0.25
0.51
0.25
5.00
4.00
A
A1
B
C
D
E
e
1.35
1.10
0.33
0.19
4.80
3.80
0.013
0.0075 0.0098
.1890 .1968
0.020
Index
Area
E
H
0.1497 0.1574
0.050 Basic
1.27 Basic
H
h
L
5.80
0.25
0.40
0°
6.20
0.50
1.27
8°
0.2284 0.2440
0.010
0.016
0°
0.020
0.050
8°
Pin 1
a
D
h x 450
A
Q
c
e
b
Ordering Information
Part / Order Number
Marking
Shipping Packaging
Tubes
Package
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
Temperature
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
MK1726-08S*
MK1726-08STR*
MK1726-08SLF
MK1726-08SLFTR
see previous page
see previous page
see previous page
see previous page
Tape and Reel
Tubes
Tape and Reel
*NOTE: EOL for non-green parts to occur on 5/13/10 per PDN U-09-01
“LF” designates Pb (lead) free package.
While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes
no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would result from its use. No
other circuits, patents, or licenses are implied. This product is intended for use in normal commercial applications. Any other applications
such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not
recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT
does not authorize or warrant any IDT product for use in life support devices or critical medical instruments.
IDT™ SPREAD SPECTRUM CLOCK GENERATOR
7
MK1726-08
REV C 121809
MK1726-08
SPREAD SPECTRUM CLOCK GENERATOR
SSCG
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