ICS309RIT [ICSI]
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER; 可编程串行TRIPLE SS PLL合成器VERSACLOCK型号: | ICS309RIT |
厂家: | INTEGRATED CIRCUIT SOLUTION INC |
描述: | SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER |
文件: | 总8页 (文件大小:133K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
ICS309
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER
Description
Features
The ICS309 is a versatile serially-programmable, triple
PLL with spread spectrum clock source. The ICS309
can generate any frequency from 250kHz to 200 MHz,
and up to 6 different output frequencies simultaneously.
The outputs can be reprogrammed on-the-fly, and will
lock to a new frequency in 10 ms or less.
• Packaged in 20-pin SSOP (QSOP)
• Highly accurate frequency generation
•M/N Multiplier PLL: M = 1..2048, N = 1..1024
• Serially programmable: user determines the output
frequency via a 3-wire interface
• Spread Spectrum frequency modulation for reduced
To reduce system EMI emissions, spread spectrum is
available that supports modulation frequencies of
31 kHz and 120 kHz, as well as modulation amplitudes
of +/-0.25% to +/-2.0%. Both center and down-spread
options are available.
system EMI
•Center or Down Spread up to 4% total
•Selectable 32 kHz and 120 kHz modulation
• Eliminates need for custom quartz oscillators
• Input crystal frequency of 5 - 27 MHz
• Input clock frequency of 3 - 50 MHz
• Output clock frequencies up to 200 MHz
• Operating voltage of 3.3 V
The device includes a PDTS pin which tri-states the
output clocks and powers down the entire chip.
The ICS309 default for non-programmed start-up are
buffered reference clock outputs on all clock output
pins.
TM
ICS’ VersaClock programming software allows the
• Up to 9 reference clock outputs
• Power down tri-state mode
user to configure up to 9 outputs with target
frequencies, spread spectrum capabilities or buffered
TM
reference clock outputs. The VersaClock software
• Very low jitter
automatically configures the PLLs for optimal overall
performance.
Block Diagram
3
VDD
PLL1 with
Spread
Spectrum
CLK1
CLK2
CLK3
CLK4
CLK5
CLK6
CLK7
CLK8
CLK9
STROBE
SCLK
DATA
Divide
Logic
and
Output
Enable
Control
PLL2
PLL3
Crystal or
clock input
X1/ICLK
Crystal
Oscillator
X2
GND
2
External capacitors are
required with a crystal input.
PDTS
MDS 309 G
1
Revision 122704
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS309
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER
Pin Assignment
DATA
1
20
19
18
17
16
15
14
13
12
11
STROBE
SCLK
PDTS
VDD
X2
2
X1/ICLK
CLK9
VDD
3
4
5
VDD
GND
6
GND
CLK1
CLK2
CLK3
CLK4
7
CLK5
CLK6
CLK7
CLK8
8
9
10
20 pin (150 mil) SSOP (QSOP)
Pin Descriptions
Pin
Pin
Pin
Pin Description
Number
Name
Type
1
2
DATA
X2
Input
XO
Serial data input.
Crystal Output. Connect this pin to a crystal. Float for clock input.
Connect this pin to a crystal or external clock input.
3
X1/ICLK
CLK9
VDD
XI
4
Output
Power
Power
Output
Output
Output
Output
Output
Output
Output
Output
Power
Power
Power
Input
Output clock 9. Default of Reference frequency output when unprogrammed.
Connect to +3.3V.
5
6
GND
Connect to Ground.
7
CLK1
CLK2
CLK3
CLK4
CLK8
CLK7
CLK6
CLK5
GND
Output clock 1. Default of Reference frequency output when unprogrammed.
Output clock 2. Default of Reference frequency output when unprogrammed.
Output clock 3. Default of Reference frequency output when unprogrammed.
Output clock 4. Default of Reference frequency output when unprogrammed.
Output clock 8. Default of Reference frequency output when unprogrammed.
Output clock 7. Default of Reference frequency output when unprogrammed.
Output clock 6. Default of Reference frequency output when unprogrammed.
Output clock 5. Default of Reference frequency output when unprogrammed.
Connect to Ground.
8
9
10
11
12
13
14
15
16
17
18
19
20
VDD
Connect to +3.3 V.
VDD
Connect to +3.3 V.
PDTS
SCLK
STROBE
Powers down entire chip, tri-states all outputs when low. Internal pull-up.
Serial Shift register clock. See timing diagram.
Input
Input
Strobe to load data. See timing diagram. Use external 250 kOhm pull-up.
MDS 309 G
2
Revision 122704
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS309
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER
Configuring the ICS309
Initial State: The ICS309 may be configured to have up to 9 frequency outputs, utilizing the 4 on-board
PLLs and spread spectrum circuitry. Unprogrammed, the part has the following outputs, related to the
reference input clock:
Default Outputs
Output
Frequency
Clocks 1 - 9 (Pins 4, 7-14)
Reference Output
The STROBE pin must have an external 250 kOhm pull-up resistor to acheive the Initial State.
The input crystal range for the ICS309 is 5 MHz to 27 MHz.
The ICS309 can be programmed to set the output functions and frequencies. 160 data bits generated by
TM
the VersaClock software are written in DATA pin in this order: MSB (left most bit) first.
As show in Figure 2, after these 160 bits are clocked into the ICS309, taking STROBE high will send this
data to the internal latch and the CLK output will lock within 10 ms.
Note: STROBE utilizes a transparent latch that is latched when in the high state. If STROBE is in the high
state and SCLK is pulsed, DATA is clocked directly to the internal latch and the output conditions will
change accordingly. Although this will not damage the ICS309, it is recommended that STROBE be kept
low while DATA is being clocked into the ICS309 in order to avoid unintended changes on the output clocks.
All outputs may be turned off during initialization by bringing the PDTS pin to Ground. When PDTS is
brought high, after the Strobe pin in brought high, the programmed output frequencies will be available.
AC Parameters for Writing to the ICS309
Parameter
tSETUP
tHOLD
tW
Condition
Setup time
Min.
10
Max.
Units
ns
Hold time after SCLK
Data wait time
10
ns
10
ns
tS
Strobe pulse width
SCLK Frequency
40
ns
30
MHz
DATA
tsetup
Bit160 Bit159 Bit158
Bit3
Bit2
Bit1
thold
SCLK
tw
ts
STROBE
Figure 2. Timing Diagram for Programming the ICS309
MDS 309 G
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Revision 122704
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS309
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER
External Components
trace to VDD pin should be kept as short as possible,
as should the PCB trace to the ground via.
Series Termination Resistor
Clock output traces over one inch should use series
termination. To series terminate a 50Ω trace (a
commonly used trace impedance), place a 33Ω resistor
in series with the clock line, as close to the clock output
pin as possible. The nominal impedance of the clock
output is 20Ω.
2) The external crystal should be mounted just next to
the device with short traces. The X1 and X2 traces
should not be routed next to each other with minimum
spaces, instead they should be separated and away
from other traces.
3) To minimize EMI, the 33Ω series termination resistor
(if needed) should be placed close to each clock
output.
STROBE Pull-up Resistor
In order for the device to start up in the default state, a
250 kOhm pull-up resistor is required.
4) An optimum layout is one with all components on the
same side of the board, minimizing vias through other
signal layers.
Decoupling Capacitors
As with any high-performance mixed-signal IC, the
ICS309 must be isolated from system power supply
noise to perform optimally.
ICS309 Configuration Capabilities
The architecture of the ICS309 allows the user to easily
configure the device to a wide range of output
frequencies, for a given input reference frequency.
Decoupling capacitors of 0.01µF must be connected
between each VDD and the PCB ground plane.
The frequency multiplier PLL provides a high degree of
precision. The M/N values (the multiplier/divide values
available to generate the target VCO frequency) can be
set within the range of M = 1 to 2048 and N = 1 to 1024.
Crystal Load Capacitors
The device crystal connections should include pads for
small capacitors from X1 to ground and from X2 to
ground. These capacitors are used to adjust the stray
capacitance of the board to match the nominally
required crystal load capacitance. Because load
capacitance can only be increased in this trimming
process, it is important to keep stray capacitance to a
minimum by using very short PCB traces (and no vias)
been the crystal and device. Crystal capacitors must be
connected from each of the pins X1 and X2 to ground.
The ICS309 also provides separate output divide
values, from 2 through 20, to allow the two output clock
banks to support widely differing frequency values from
the same PLL.
Each output frequency can be represented as:
Output Freq. = (Ref. Freq)*(M/N)/Output Divide
The value (in pF) of these crystal caps should equal
ICS VersaClock Software
(C -6 pF)*2. In this equation, C = crystal load
L
L
capacitance in pF. Example: For a crystal with a 16 pF
load capacitance, each crystal capacitor would be 20
pF [(16-6) x 2] = 20.
ICS applies years of PLL optimization experience into a
user friendly software that accepts the user’s target
reference clock and output frequencies and generates
the lowest jitter, lowest power configuration, with only a
press of a button. The user does not need to have prior
PLL experience or determine the optimal VCO
PCB Layout Recommendations
For optimum device performance and lowest output
phase noise, the following guidelines should be
observed.
frequency to support multiple output frequencies.
VersaClock software quickly evaluates accessible VCO
frequencies with available output divide values and
provides an easy to understand, bar code rating for the
target output frequencies. The user may evaluate
output accuracy, performance trade-off scenarios in
seconds.
1) Each 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 decoupling capacitor and VDD pin. The PCB
MDS 309 G
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Revision 122704
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS309
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER
frequency. The effective average frequency is less than
the target frequency.
Spread Spectrum Modulation
The ICS309 utilizes frequency modulation (FM) to
distribute energy over a range of frequencies. By
modulating the output clock frequencies, the device
effectively lowers energy across a broader range of
frequencies; thus, lowering a system’s
electro-magnetic interference (EMI). The modulation
rate is the time from transitioning from a minimum
frequency to a maximum frequency and then back to
the minimum.
The ICS309 operates in both center spread and down
spread modes. For center spread, the frequency can
be modulated between 0.125% to 2.0%. For down
spread, the frequency can be modulated between
-0.25% to -4.0%.
Both output frequency banks will utilize identical spread
spectrum percentage deviations and modulation rates,
if a common VCO frequency can be identified.
Spread Spectrum Modulation can be applied as either
“center spread” or “down spread”. During center spread
modulation, the deviation from the target frequency is
equal in the positive and negative directions. The
effective average frequency is equal to the target
frequency. In applications where the clock is driving a
component with a maximum frequency rating, down
spread should be applied. In this case, the maximum
frequency, including modulation, is the target
Spread Spectrum Modulation Rate
The spread spectrum modulation frequency applied to
the output clock frequency may occur at a variety of
rates. For applications requiring the driving of
“down-circuit” PLLs, Zero Delay Buffers, or those
adhering to PCI standards, the spread spectrum
modulation rate should be set to 30-33 kHz. For other
applications, a 120 kHz modulation option is available.
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS309. These ratings, which
are standard values for ICS 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.
Parameter
Condition
Min.
Typ.
Max.
7
Units
V
Supply Voltage, VDD
Inputs
Referenced to GND
Referenced to GND
Referenced to GND
-0.5
-0.5
-65
VDD+ 0.5
VDD+ 0.5
150
V
Clock Outputs
V
Storage Temperature
Soldering Temperature
°C
°C
Max 10 seconds
260
Recommended Operation Conditions
Parameter
Min.
0
Typ.
Max.
+70
+85
+3.6
4
Units
°C
Ambient Operating Temperature
Ambient Operating Temperature (ICS309RI)
Power Supply Voltage (measured in respect to GND)
Power Supply Ramp Time
-40
+3.0
°C
V
ms
MDS 309 G
5
Revision 122704
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS309
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER
DC Electrical Characteristics
VDD=3.3 V ±±0ꢀ, Ambient temperature -40 to +85°C, unless stated otherwise
Parameter
Symbol
VDD
Conditions
Min.
Typ.
Max.
Units
V
Operating Voltage
3.00
3.60
Operating Supply Current
Input High Voltage
IDD
Configuration
mA
Dependent - See
TM
VersaClock
Estimates
Ex. 25 MHz crystal,
VDD=3.3V, No load,
9 - 33.3333 MHz outs,
PDTS = 1
25
20
mA
PDTS = 0
µA
V
Input High Voltage
Input Low Voltage
Input High Voltage
V
X1/ICLK only
X1/ICLK only
(VDD/2)+1
VDD-0.5
IH
V
(VDD/2)-1
0.8
V
IL
V
V
IH
Input Low Voltage
V
PDTS, SCLK, DATA,
STROBE
V
IL
Output High Voltage
Output Low Voltage
V
I
I
I
= -8 mA
= 8 mA
= -4 mA
2.4
V
V
V
OH
OH
OL
OH
V
0.4
OL
Output High Voltage,
CMOS level
V
VDD-0.4
OH
Short Circuit Current
Input Capacitance
CLK outputs
PDTS pin
+70
4
mA
pF
C
IN
Internal pull-down resistor
R
CLK outputs
525
kΩ
PD
Internal Pull-up Resistor
R
PDTS pin
250
kΩ
PU
AC Electrical Characteristics
VDD = 3.3 V ±±0ꢀ, Ambient Temperature -40 to +85° C, unless stated otherwise
Parameter
Symbol
Conditions
Min. Typ. Max. Units
Input Frequency
F
Fundamental crystal
5
27
MHz
IN
Input Clock
VDD=3.3 V
2
50
MHz
MHz
Output Frequency
0.25
200
Output Clock Rise Time
Output Clock Fall Time
Output Clock Duty Cycle
t
20% to 80%, Note 1
80% to 20%, Note 1
Note 2
0.8
0.8
ns
ns
%
OR
t
OF
40
49-51
60
MDS 309 G
6
Revision 122704
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS309
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER
Parameter
Symbol
Conditions
Min. Typ. Max. Units
Power-up time
PDTS goes high until
stable CLK output
4
10
ms
PDTS goes high until
stable CLK out,
.2
2
ms
Spread Spectrum off
PDTS goes high until
stable CLK out,
4
7
ms
Spread Spectrum On
Maximum Output Jitter, short term
Maximum Output Jitter, short term
t
t
Reference Clock
300
200
ps
ps
j
j
All other clocks,
C =15 pF
L
Configuration
Pin-to-Pin Skew
Low Skew Outputs
-250
250
ps
Note 1: Measured with 15 pF load.
Note 2: Duty Cycle is configuration dependent. Most configurations are min 45% / max 55%
Thermal Characteristics
Parameter
Symbol
Conditions
Min.
Typ. Max. Units
Thermal Resistance Junction to
Ambient
θ
θ
θ
Still air
135
93
°C/W
°C/W
°C/W
°C/W
JA
JA
JA
JC
1 m/s air flow
3 m/s air flow
78
Thermal Resistance Junction to Case
θ
60
MDS 309 G
7
Revision 122704
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS309
SERIAL PROGRAMMABLE TRIPLE PLL SS VERSACLOCK SYNTHESIZER
Package Outline and Package Dimensions (20-pin SSOP, ±50 Mil. Wide Body)
Package dimensions are kept current with JEDEC Publication No. 95
20
Millimeters
Inches
Symbol
Min
Max
1.75
0.25
1.50
0.30
0.25
8.75
6.20
4.00
Min
Max
A
A1
A2
b
1.35
0.10
--
0.20
0.18
8.55
5.80
3.80
0.053
0.004
--
0.008
0.007
0.337
0.228
0.150
0.069
0.010
0.059
0.012
0.010
0.344
0.244
0.157
E1
E
INDEX
AREA
c
D
E
1 2
E1
e
.635 Basic
.025 Basic
D
L
0.40
0°
1.27
8°
0.016
0°
0.050
8°
α
aaa
--
0.10
--
0.004
A
A2
A1
c
- C -
e
SEATING
PLANE
b
L
aaa C
Ordering Information
Part / Order Number
Marking
Shipping packaging
Tubes
Package
Temperature
0 to +70° C
0 to +70° C
-40 to +85° C
-40 to +85° C
ICS309R
ICS309RT
ICS309RI
ICS309RIT
ICS309R (top line)
YYWW (2nd line)
20-pin SSOP
20-pin SSOP
20-pin SSOP
20-pin SSOP
Tape and Reel
Tubes
Tape and Reel
ICS309RI (top line)
YYWW (2nd line)
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems (ICS)
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 ICS. ICS reserves the right to change any
circuitry or specifications without notice. ICS does not authorize or warrant any ICS product for use in life support devices or
critical medical instruments.
MDS 309 G
8
Revision 122704
Integrated Circuit Systems ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
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