MK3721 ICST | Alldatasheet

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Technical content

Low Cost 3.3 Volt VCXO Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA • 95126• (408)295-9800tel • www.icst.com ICR OCLOC K Block Diagram Description Features The MK3721 is ICS/MicroClock’s lowest cost, low jitter, high performance 3.3 volt VCXO designed to replace expensive VCXO modules. The on-chip Voltage Controlled Crystal Oscillator accepts a 0 to 3.3 V input voltage to cause the output clocks to vary by ±100 ppm. Using ICS/MicroClock’s patented VCXO techniques, the device uses an inexpensive external pullable crystal in the range of 16.2 - 28 MHz to produce a VCXO output clock at that same frequency. ICS/MicroClock manufactures the largest variety of Set-Top Box and multimedia clock synthesizers for all applications. If more clock outputs are needed, see the MK3732 or MK377x family of parts. Consult ICS/MicroClock to eliminate VCXOs, crystals and oscillators from your board.

  • Packaged in 8 pin SOIC
  • 3.3 V operating voltage
  • 16.2 MHz to 28 MHz operation
  • Uses an inexpensive external crystal
  • On-chip VCXO (patented) with pull range of 200 ppm (minimum)
  • VCXO tuning voltage of 0 to 3.3 V
  • 12 mA output drive capability at TTL levels
  • Advanced, low power, sub-micron CMOS process
  • For frequencies between 8 MHz to 16 MHz, use the MK3711A. For frequencies between 1 MHz and 8 MHz, use the MK3713. For higher than

28 MHz, use the MK3732-05

16.2 -28 MHz pullable crystal VIN Output Buffer 16.2 - 28 MHz Clock (REFOUT)

Low Cost 3.3 Volt VCXO Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA • 95126• (408)295-9800tel • www.icst.com ICR OCLOC K Pin Descriptions Pin Assignment Number Name Description 1 X1 Crystal connection. Connect to a pullable 16.2 - 28 MHz crystal. 2 VDD VDD. Connect to + 3.3 V. 3 VIN Voltage input to VCXO. Zero to 3.3 V analog input which controls the frequency of the VCXO. 4 GND Connect to ground. 5 DC Don't Connect anything to this pin. 6 REFOUT VCXO CMOS level clock output matches the nominal frequency of the crystal. 7 DC Don't Connect anything to this pin. 8 X2 Crystal connection. Connect to a pullable 16.2 - 28 MHz crystal. 8 pin (150 mil) SOIC MK3721 1 8 X2X1 GND VDD DC VIN DC REFOUT (VCXO) Crystal Specifications Correlation (load) capacitance 14 pF Initial accuracy ±20 ppm maximum Drift over temperature and aging ±50 ppm maximum C0/C1 ratio 240 maximum ESR 35 Ω maximum

Low Cost 3.3 Volt VCXO Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA • 95126• (408)295-9800tel • www.icst.com ICR OCLOC K Parameter Conditions Minimum Typical Maximum Units ABSOLUTE MAXIMUM RATINGS (note 1) ABSOLUTE MAXIMUM RATINGS (note 1) Supply voltage, VDD Referenced to GND 7 V Inputs and Clock Outputs Referenced to GND -0.5 VDD+0.5 V Ambient Operating Temperature 0 70 °C Soldering Temperature Max of 10 seconds 260 °C Storage temperature -65 150 °C DC CHARACTERISTICS (VDD = 3.3 V unless noted)DC CHARACTERISTICS (VDD = 3.3 V unless noted) Operating Voltage, VDD 3.15 3.45 V Output High Voltage, VOH IOH=-12mA 2.4 V Output Low Voltage, VOL IOL=12mA 0.4 V Output High Voltage, VOH, CMOS level IOH=-4mA VDD-0.4 V Operating Supply Current, IDD No Load 4 mA Short Circuit Current ±50 mA VIN, VCXO control voltage 0 3.3 V AC CHARACTERISTICS (VDD = 3.3 V unless noted)AC CHARACTERISTICS (VDD = 3.3 V unless noted) Input Crystal Frequency 16.2 28 MHz Input Crystal Accuracy ±30 ppm Output Clock Rise Time 0.8 to 2.0V 1.5 ns Output Clock Fall Time 2.0 to 0.8V 1.5 ns Output Clock Duty Cycle At VDD/2 40 50 60 % Maximum Absolute Jitter, short term ±55 ps Output frequency pullability, note 2 0V ≤ VIN ≤ 3.3 V ±100 ppm Electrical Specifications Notes: 1. Stresses beyond those listed under Absolute Maximum Ratings could cause permanent damage to the device. Prolonged exposure to levels above the operating limits but below the Absolute Maximums may affect device reliability. 2. With a ICS/MicroClock approved pullable crystal. External Components The MK3721 requires a minimum number of external components for proper operation. A decoupling capacitor of 0.01µF should be connected between VDD and GND on pins 2 and 4, as close to the MK3721 as possible. A series termination resistor of 33 Ω may be used for the clock output. The input crystal must be connected as close to the chip as possible. The input crystal should be a parallel mode, pullable, AT cut, with 14 pF load capacitance. See previous page for crystal specifications. Consult ICS for recommended suppliers. IMPORTANT - read application note MAN05 before laying out the PCB.

Low Cost 3.3 Volt VCXO Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA • 95126• (408)295-9800tel • www.icst.com ICR OCLOC K While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems Incorporated (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.

Ordering Information

Part/Order Number Marking Shipping packaging Package Temperature MK3721S MK3721S tubes 8 pin SOIC 0-70 °C MK3721STR MK3721S tape and reel 8 pin SOIC 0-70 °C C A B D E H e L Package Outline and Package Dimensions (For current dimensional specifications, see JEDEC Publication No. 95.) 8 pin SOIC Inches Inches Millimeters Millimeters Symbol Min Max Min Max A 0.0532 0.0688 1.35 1.75 A1 0.0040 0.0098 0.10 0.24 B 0.0130 0.0200 0.33 0.51 C 0.0075 0.0098 0.19 0.24 D 0.1890 0.1968 4.80 5.00 E 0.1497 0.1574 3.80 4.00 e .050 BSC .050 BSC 1.27 BSC 1.27 BSC H 0.2284 0.2440 5.80 6.20 h 0.0099 0.0195 0.25 0.50 L 0.0160 0.0500 0.41 1.27 INDEX AREA