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ICS270 - ICS270
ICS270
Triple Field Programmable VCXO Clock Synthesizer
ICS270 field programmable VCXO clock synthesizer generates eight high-quality, high-frequency clock outputs including multiple reference clocks from low-frequency crystal input. designed replace crystals crystal oscillators most electronic systems. Using ICS' VersaClocksoftware configure PLLs outputs, ICS270 contains One-Time Programmable (OTP) field programmability. Programming features include VCXO, eight selectable configuration registers sets four low-skew outputs. Using Phase-Locked Loop (PLL) techniques, device runs from standard fundamental mode, inexpensive crystal, clock. replace VCXOs, multiple crystals oscillators, saving board space cost. ICS270 also available factory programmed custom versions high-volume applications.
Features
Packaged 20-pin TSSOP Eight addressable registers Replaces multiple crystals oscillators Output frequencies Input crystal frequency eight reference outputs sets four low-skew outputs Operating voltages Controllable output drive levels Advanced, low-power CMOS process Available (lead) free packaging
Block Diagram
S2:S0
with Values
CLK1 PLL1 CLK2 Divide Logic Output Enable Control CLK3 CLK4 CLK5 CLK6 CLK7 CLK8
PLL2
PLL3 Crystal External capacitors required. Voltage Controlled Crystal Oscillator
PDTS
Integrated Circuit Systems, Inc.
Race Street, Jose, 95126
Revision 040705 (408) 297-1201
www.icst.com
ICS270 Triple Field Programmable VCXO Clock
Assignment
CLK1 CLK2 CLK3 CLK4 PDTS CLK8 CLK7 CLK6 CLK5
(173 mil) TSSOP
Descriptions
Number
Name
CLK1 CLK2 CLK3 CLK4 CLK5 CLK6 CLK7 CLK8 PDTS
Type
Input Input Input Power Output Output Output Output Power Power Output Output Output Output Power Input Power Input
Voltage input VCXO. Zero signal which controls VCXO frequency Select Internal pull-up resistor. Select Internal pull-up resistor. Connect +3.3 Output clock Weak internal pull-down when tri-state. Output clock Weak internal pull-down when tri-state. Output clock Weak internal pull-down when tri-state. Output clock Weak internal pull-down when tri-state. Connect ground. Crystal input. Connect this crystal. Crystal Output. Connect this crystal. Connect +3.3 Output clock Weak internal pull-down when tri-state. Output clock Weak internal pull-down when tri-state. Output clock Weak internal pull-down when tri-state. Output clock Weak internal pull-down when tri-state. Connect ground. Power-down tri-state. Powers down entire chip tri-states clock outputs when low. Internal pull-up resistor. Connect +3.3 Select Internal pull-up resistor.
Integrated Circuit Systems, Inc.
Race Street, Jose, 95126
Revision 040705 (408) 297-1201
www.icst.com
ICS270 Triple Field Programmable VCXO Clock
External Components
ICS270 requires minimum number external components proper operation. external crystal must connected close chip possible should same side ICS270. There should via's between crystal pins device pins. There should signal traces underneath close crystal. application note MAN05.
Series Termination Resistor
Clock output traces over inch should series termination. series terminate trace commonly used trace impedance), place resistor series with clock line, close clock output possible. nominal impedance clock output
Crystal Tuning Load Capacitors
crystal traces should include pads small fixed capacitors, between ground, another between ground. Stuffing these capacitors optional. need these capacitors determined system prototype evaluation, influenced particular crystal used (manufacture frequency) layout. typical required capacitor value determine need value crystal adjustment capacitors, will need board your final layout, frequency counter capable about resolution accuracy, power supplies, some samples crystals which plan production, along with measured initial accuracy each crystal specified crystal load capacitance, determine value crystal capacitors: Connect ICS270 Connect ICS270 second power supply. Adjust voltage Measure record frequency output. Adjust voltage Measure record frequency same output. calculate centering error:
Decoupling Capacitors
with high-performance mixed-signal ICS270 must isolated from system power supply noise perform optimally. Decoupling capacitors 0.01µF must connected between each ground plane. optimum device performance, decoupling capacitor should mounted component side PCB. Avoid vias decoupling circuit.
Quartz Crystal
ICS270 VCXO function consists external crystal integrated VCXO oscillator circuit. assure best system performance (frequency pull range) reliability, crystal device with recommended parameters (shown below) must used, layout guidelines discussed following section shown must followed. frequency oscillation quartz crystal determined "cut" load capacitors connected ICS270 incorporates on-chip variable load capacitors that "pull" (change) frequency crystal. crystal specified with ICS270 designed have zero frequency error when total on-chip stray capacitance Recommended Crystal Parameters: Initial Accuracy 25°C Temperature Stability Aging Load Capacitance Shunt Capacitance, C0/C1 Ratio Equivalent Series Resistance
f3.0V Error errorxtal
Where: ftarget nominal crystal frequency
Integrated Circuit Systems, Inc.
Race Street, Jose, 95126
Revision 040705 (408) 297-1201
www.icst.com
ICS270 Triple Field Programmable VCXO Clock
errorxtal =actual initial accuracy ppm) crystal being measured centering error less than ppm, adjustment needed. centering error more than 25ppm negative, board excessive stray capacitance layout should considered reduce stray capacitance. (Alternately, crystal re-specified higher load capacitance. Contact details.) centering error more than positive, identical fixed centering capacitors from each crystal ground. value each these caps given External Capacitor (centering error)/(trim sensitivity) Trim sensitivity parameter which supplied your crystal vendor. know value, assume ppm/pF. After changes, repeat measurement verify that remaining error acceptably (typically less than ppm).
banks support widely differing frequency values from same PLL. Each output frequency represented
OutputFreq
REFFreq
Output Drive Control
ICS270 output drive settings. drive should selected when outputs less than MHz. High drive should selected when outputs greater than MHz. (Consult Electrical Characteristics output rise fall times each drive option.)
VersaClock Software
applies years optimization experience into user friendly software that accepts user's target reference clock output frequencies generates lowest jitter, lowest power configuration, with only press button. user does need have prior experience determine optimal frequency support multiple output frequencies. VersaClock software quickly evaluates accessible frequencies with available output divide values provides easy understand, code rating target output frequencies. user evaluate output accuracy, performance trade-off scenarios seconds.
ICS270 Configuration Capabilities
architecture ICS270 allows user easily configure device wide range output frequencies, given input reference frequency. frequency multiplier provides high degree precision. values (the multiplier/divide values available generate target frequency) within range 1024 32,895. ICS270 also provides separate output divide values, from through allow output clock
Absolute Maximum Ratings
Stresses above ratings listed below cause permanent damage ICS270. These ratings, which standard values commercially rated parts, stress ratings only. Functional operation device these other conditions above those indicated operational sections specifications implied. Exposure absolute maximum rating conditions extended periods affect product reliability. Electrical parameters guaranteed only over recommended operating temperature range.
Parameter
Supply Voltage, Inputs Clock Outputs
Condition
Referenced Referenced Referenced
Min.
-0.5 -0.5
Typ.
Max.
VDD+0.5 VDD+0.5
Units
Integrated Circuit Systems, Inc.
Race Street, Jose, 95126
Revision 040705 (408) 297-1201
www.icst.com
ICS270 Triple Field Programmable VCXO Clock
Parameter
Storage Temperature Soldering Temperature Junction Temperature
Condition
seconds
Min.
Typ.
Max.
Units
Recommended Operation Conditions
Parameter
Ambient Operating Temperature (ICS270PG/PGLF) Ambient Operating Temperature (ICS270PGI/PGILF) Power Supply Voltage (measured respect GND) Power Supply Ramp Time Reference crystal parameters
Min.
+3.135
Typ.
Max.
Units
+3.3
+3.465
Refer page
Electrical Characteristics
Unless stated otherwise, ±5%, Ambient Temperature +85°C
Parameter
Operating Voltage
Symbol
Conditions
Config. Dependent VersaClockEstimates
Min.
3.135
Typ.
Max.
3.465
Units
Operating Supply Current Input High Voltage Input High Voltage Input Voltage Input High Voltage, PDTS Input Voltage, PDTS Input High Voltage Input Voltage Output High Voltage (CMOS High) Output High Voltage Output Voltage Short Circuit Current Nom. Output Impedance
Eight 33.3333 outs, PDTS load, Note PDTS load, Note S2:S0 S2:S0 VDD-0.5 VDD/2+1
VDD/2-1
ICLK ICLK (Low Drive); (High Drive) (Low Drive); (High Drive) Drive High Drive
VDD/2+1 VDD-0.4
Integrated Circuit Systems, Inc.
Race Street, Jose, 95126
Revision 040705 (408) 297-1201
www.icst.com
ICS270 Triple Field Programmable VCXO Clock
Parameter
Internal Pull-up Resistor Internal Pull-down Resistor Input Capacitance
Symbol
RPUS
Conditions
S2:S0, PDTS outputs Inputs
Min.
Typ.
Max.
Units
Note Example with crystal input with eight outputs 33.3 MHz, load,
Electrical Characteristics
Unless stated otherwise, ±5%, Ambient Temperature +85°
Parameter
Input Frequency Output Frequency Crystal Pullability VCXO Gain Output Rise/Fall Time Output Rise/Fall Time Duty Cycle Power-up time
Symbol
Conditions
Fundamental crystal Note VDD/2 Note
Min.
0.314
Typ.
Max. Units
ppm/V
49-51 +200 -250
20%, high drive, Note 20%, drive, Note Note lock-time from power-up PDTS goes high until stable output
Sigma Clock Period Jitter Maximum Absolute Jitter Pin-to-Pin Skew
Configuration Dependent Deviation from Mean, Configuration Dependent Skew Outputs
Note External crystal device must conform with Pullable Crystal Specifications listed page Note Measured with load. Note Duty Cycle configuration dependent. Most configurations 55%.
Thermal Characteristics
Parameter
Thermal Resistance Junction Ambient
Symbol
Conditions
Still flow flow
Min.
Typ.
Max. Units
°C/W °C/W °C/W °C/W
Thermal Resistance Junction Case
Integrated Circuit Systems, Inc.
Race Street, Jose, 95126
Revision 040705 (408) 297-1201
www.icst.com
ICS270 Triple Field Programmable VCXO Clock
Marking Diagrams
Marking Diagrams free)
270PG ###### YYWW
270PGL ###### YYWW
270PGI ###### YYWW
270PGIL ###### YYWW
Notes: ###### number. YYWW last digits year week that part assembled. denotes industrial temperature range applicable). denotes (lead) free package. Bottom marking: country origin.
Integrated Circuit Systems, Inc.
Race Street, Jose, 95126
Revision 040705 (408) 297-1201
www.icst.com
ICS270 Triple Field Programmable VCXO Clock
Package Outline Package Dimensions (20-pin TSSOP, Mil. Body)
Package dimensions kept current with JEDEC Publication
Millimeters Symbol
Inches
INDEX AREA
1.20 0.05 0.15 0.80 1.05 0.19 0.30 0.09 0.20 6.40 6.60 6.40 BASIC 4.30 4.50 0.65 Basic 0.45 0.75
.047 0.002 0.006 0.032 0.041 0.007 0.012 0.0035 0.008 0.252 0.260 0.252 BASIC 0.169 0.177 0.0256 Basic .018 .030
SEATING PLANE
(.004)
Ordering Information
Part Order Number
ICS270PG ICS270PGI ICS270PGLF ICS270PGILF page
Marking
Shipping Packaging
Tubes Tubes Tubes Tubes
Package
20-pin TSSOP 20-pin TSSOP 20-pin TSSOP 20-pin TSSOP
Temperature
+70°C +85°C +70°C +85°C
Parts that ordered with "LF" suffix part number Pb-Free configuration RoHS compliant. While information presented herein been checked both accuracy reliability, Integrated Circuit Systems (ICS) assumes responsibility either infringement patents other rights third parties, which would result from use. other circuits, patents, licenses implied. This product intended normal commercial applications. other applications such those requiring extended temperature range, high reliability, other extraordinary environmental requirements recommended without additional processing ICS. reserves right change circuitry specifications without notice. does authorize warrant product life support devices critical medical instruments. VersaClockis trademark Integrated Circuit Systems, Inc. rights reserved.
Integrated Circuit Systems, Inc.
Race Street, Jose, 95126
Revision 040705 (408) 297-1201
www.icst.com
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