http://www.www.datasheet4u.com

900,000+ Datasheet PDF Search and Download

Datasheet4U offers most rated semiconductors datasheets pdf



Integrated Device Technology Electronic Components Datasheet

ICS290 Datasheet

Triple PLL Field Prog. Spread Spectrum Clock Synthesizer

No Preview Available !

ICS290 pdf
PRELIMINARY INFORMATION
ICS290www.DataSheet4U.com
Triple PLL Field Prog. Spread Spectrum Clock Synthesizer
Description
The ICS290 field programmable spread spectrum
clock synthesizer generates up to eight high-quality,
high-frequency clock outputs including multiple
reference clocks from a low-frequency crystal input. It
is designed to replace crystals, crystal oscillators and
stand alone spread spectrum devices in most
electronic systems.
Using ICS’ VersaClockTM software to configure PLLs
and outputs, the ICS290 contains a One-Time
Programmable (OTP) ROM for field programmability.
Programming features include input/output
frequencies, spread spectrum amount, eight selectable
configuration registers and up to two sets of four
low-skew outputs.
Using Phase-Locked Loop (PLL) techniques, the
device runs from a standard fundamental mode,
inexpensive crystal, or clock. It can replace multiple
crystals and oscillators, saving board space and cost.
The ICS290 is also available in factory programmed
custom versions for high-volume applications.
Features
Packaged as 20-pin TSSOP
Eight addressable registers
Replaces multiple crystals and oscillators
Output frequencies up to 200 MHz at 3.3 V
Configurable Spread Spectrum Modulation
Input crystal frequency of 5 to 27 MHz
Clock input frequency of 3 to 166 MHz
Up to eight reference outputs
Up to two sets of four low-skew outputs
Operating voltages of 3.3 V
Controllable output drive levels
Advanced, low-power CMOS process
Available in Pb (lead) free packaging
Block Diagram
S2:S0 3
OTP
ROM
with PLL
Values
X1/ICLK
Crystal or
Clock Input
X2
Crystal
Oscillator
External capacitors
are required with a crystal input.
VDD 3
PLL1 with
Spread
Spectrum
PLL2
PLL3
Divide
Logic
and
Output
Enable
Control
GND 3
PDTS
CLK1
CLK2
CLK3
CLK4
CLK5
CLK6
CLK7
CLK8
MDS 290 C
1
Revision 062305
Integrated Circuit Systems, Inc. 525 Race Street, San Jose, CA 95126 tel (408) 297-1201 www.icst.com



Integrated Device Technology Electronic Components Datasheet

ICS290 Datasheet

Triple PLL Field Prog. Spread Spectrum Clock Synthesizer

No Preview Available !

ICS290 pdf
PRELIMINARY INFORMATION
ICS290
Triple PLL Field Prog. Spread Spectrum Cwlwowck.DaStaySnhethete4Us.iczoemr
Pin Assignment
GND
S0
S1
VDD
CLK1
CLK2
CLK3
CLK4
GND
X1/ICLK
1
2
3
4
5
6
7
8
9
10
20 S2
19 VDD
18 PDTS
17 GND
16 CLK8
15 CLK7
14 CLK6
13 CLK5
12 VDD
11 X2
20 pin (173 mil) TSSOP
Pin Descriptions
Pin
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Pin
Name
GND
S0
S1
VDD
CLK1
CLK2
CLK3
CLK4
GND
X1/ICLK
X2
VDD
CLK5
CLK6
CLK7
CLK8
GND
PDTS
VDD
S2
Pin
Type
Power
Input
Input
Power
Output
Output
Output
Output
Power
XI
XO
Power
Output
Output
Output
Output
Power
Input
Power
Input
Pin Description
Connect to ground.
Select pin 0. Internal pull-up resistor.
Select pin 1. Internal pull-up resistor.
Connect to +3.3 V.
Output clock 1. Weak internal pull-down when tri-state.
Output clock 2. Weak internal pull-down when tri-state.
Output clock 3. Weak internal pull-down when tri-state.
Output clock 4. Weak internal pull-down when tri-state.
Connect to ground.
Crystal input. Connect this pin to a crystal or external input clock.
Crystal Output. Connect this pin to a crystal. Float for clock input.
Connect to +3.3 V.
Output clock 5. Weak internal pull-down when tri-state.
Output clock 6. Weak internal pull-down when tri-state.
Output clock 7. Weak internal pull-down when tri-state.
Output clock 8. Weak internal pull-down when tri-state.
Connect to ground.
Power-down tri-state. Powers down entire chip and tri-states clock outputs
when low. Internal pull-up resistor.
Connect to +3.3 V.
Select pin 2. Internal pull-up resistor.
MDS 290 C
2
Revision 062305
Integrated Circuit Systems, Inc. 525 Race Street, San Jose, CA 95126 tel (408) 297-1201 www.icst.com



Integrated Device Technology Electronic Components Datasheet

ICS290 Datasheet

Triple PLL Field Prog. Spread Spectrum Clock Synthesizer

No Preview Available !

ICS290 pdf
PRELIMINARY INFORMATION
ICS290
Triple PLL Field Prog. Spread Spectrum Cwlwowck.DaStaySnhethete4Us.iczoemr
External Components
The ICS290 requires a minimum number of external
components for proper operation.
Series Termination Resistor
Clock output traces over one inch should use series
termination. To series terminate a 50trace (a
commonly used trace impedance), place a 33resistor
in series with the clock line, as close to the clock output
pin as possible. The nominal impedance of the clock
output is 20.
Decoupling Capacitors
As with any high-performance mixed-signal IC, the
ICS290 must be isolated from system power supply
noise to perform optimally.
Decoupling capacitors of 0.01µF must be connected
between each VDD and the PCB ground plane. For
optimum device performance, the decoupling capacitor
should be mounted on the component side of the PCB.
Avoid the use of vias on the decoupling circuit.
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 value (in pF) of these crystal caps should equal
(CL -6 pF)*2. In this equation, CL= crystal load
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.
ICS290 Configuration Capabilities
The architecture of the ICS290 allows the user to easily
configure the device to a wide range of output
frequencies, for a given input reference frequency.
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 1024 and N = 1 to
32,895.
The ICS290 also provides separate output divide
values, from 2 through 63, to allow the two output clock
banks to support widely differing frequency values from
the same PLL.
Each output frequency can be represented as:
OutputFreq = REFFreq M-N---
Output Drive Control
The ICS290 has two output drive settings. Low drive
should be selected when outputs are less than 100
MHz. High drive should be selected when outputs are
greater than 100 MHz. (Consult the AC Electrical
Characteristics for output rise and fall times for each
drive option.)
ICS VersaClock Software
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
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.
Spread Spectrum Modulation
The ICS290 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 electromagnetic
interference (EMI). The modulation rate is the time from
transitioning from a minimum frequency to a maximum
frequency and then back to the minimum.
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
MDS 290 C
3
Revision 062305
Integrated Circuit Systems, Inc. 525 Race Street, San Jose, CA 95126 tel (408) 297-1201 www.icst.com




Part Number ICS290
Description Triple PLL Field Prog. Spread Spectrum Clock Synthesizer
Maker Integrated Device Technology
Total Page 8 Pages
PDF Download
ICS290 pdf
Download PDF File
ICS290 pdf
View for Mobile






Related Datasheet

1 ICS290 Triple PLL Field Prog. Spread Spectrum Clock Synthesizer Integrated Device Technology
Integrated Device Technology
ICS290 pdf
2 ICS291 TRIPLE PLL FIELD PROG. SPREAD SPECTRUM CLOCK SYNTHESIZER Integrated Device Technology
Integrated Device Technology
ICS291 pdf




Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

site map

webmaste! click here

contact us

Buy Components