MK2014A Fast Ethernet Clock Source I C R O C LOC K Description Features The MK2014A is the ideal way to generate clocks for Fast Ethernet cards or systems. It provides 20MHz and 25MHz clocks from an inexpensive 14.31818 MHz crystal or clock. In an 8 pin SOIC, the MK2014A can save component count, board space, and cost over surface mount crystals and oscillators, and increase reliability by eliminating mechanical devices from the board. • Packaged in 8 pin SOIC The MK2014A is a functionally identical update of the MK2014 and should be used in all designs. The only change is in crystal load capacitance as stated on page 2. MicroClock offers many other clocks for computers and computer peripherals. Consult your MicroClock representative when you need to remove crystals and oscillators from your board. • Input crystal or clock frequency of 14.318 MHz • Lowest jitter in the industry reliably clocks sensitive Ethernet devices. • Output clock frequencies of 20.00 MHz and 25.00 MHz • Zero ppm synthesis error in the output clocks • Full CMOS outputs with 25mA drive capability at TTL levels • 3.3V or 5V±10% supply voltage • Advanced, low power CMOS process • Insensitive to input clock duty cycle Block Diagram VDD GND 2 Clock Synthesis and Control Circuitry 14.31818 MHz crystal or clock Output Buffer 20 MHz Output Buffer 25 MHz Output Buffer 14.318 MHz X1 Crystal Oscillator X2 1 Revision 121598 Printed 11/15/00 MicroClock Division of ICS • 525 Race Street • San Jose • CA • 95126•(408)295-9800tel•(408)295-9818fax MDS 2014A B MK2014A Fast Ethernet Clock Source I C R O C LOC K Suggested Layout Pin Assignment 14.3 MHz in (crystal caps not shown) Pin 1 X1/ICLK 1 8 X2 VDD 2 7 14M GND 3 6 20M 25M 4 5 GND V 0.1µF 8 pin SOIC G 8 14.3MHz out 2 7 3 6 33Ω (optional) 20MHz out 5 33Ω (optional) 4 33Ω (optional) 25MHz out Pin Descriptions Number 1 2 3 4 5 6 7 8 Name X1/ICLK VDD GND 25M GND 20M 14M X2 Type XI P P O P O O XO Description Crystal Connection. Connect to a 14.31818 MHz crystal or clock. Connect to +5V. Connect to ground. 25.000 MHz clock output. Connect to ground. 20.000 MHz clock output. 14.31818 MHz buffered crystal clock output. Crystal Connection to a 14.31818 MHz crystal, or leave unconnected for clock input. Key: I = Input, O = output, P = power supply connection External Components/Crystal Selection A minimum number of external components are required for proper oscillation. A decoupling capacitor of 0.1 µF should be connected between VDD and GND on pins 2 and 3, and 33 Ω terminating resistors should be used on clock outputs with traces longer than 1 inch. For a clock input, connect to X1 and leave X2 unconnected. For a crystal input, a parallel resonant 14.31818 MHz crystal is recommended. The frequency accuracy of the crystal should be 30 ppm or better. External capacitors from each of the X1 and X2 pins to ground should be added with a value in pF equal to (CL -13)*2, where CL is the crystal load capacitance in pF. So for a crystal with load capacitance of 16 pF, 6 pF capacitors should be used. [Note that the MK2014S required crystal load capacitors of (CL -4)*2.] 2 Revision 121598 Printed 11/15/00 MicroClock Division of ICS • 525 Race Street • San Jose • CA • 95126•(408)295-9800tel•(408)295-9818fax MDS 2014A B I C R O C LOC K MK2014A Fast Ethernet Clock Source Electrical Specifications Parameter Conditions Minimum Typical Maximum Units 7 VDD+.5V VDD+.5V 70 260 150 V V V °C °C °C 5.5 V V V V V V mA mA pF ppm ABSOLUTE MAXIMUM RATINGS (note 1) Supply Voltage, VDD Inputs Clock Outputs Ambient Operating Temperature Soldering Temperature Storage temperature Referenced to GND Referenced to GND Referenced to GND -0.5 -0.5 0 Max of 20 seconds -65 DC CHARACTERISTICS (at 5.0V unless otherwise noted) Operating Voltage, VDD Input High Voltage, VIH, input clock only Input Low Voltage, VIL, input clock only Output High Voltage, VOH Output High Voltage, VOH Output Low Voltage, VOL Operating Supply Current, IDD, 5V Operating Supply Current, IDD, 3.3V Input Capacitance Actual Mean Frequency versus Target, note 3 Clock input Clock input IOH=-4mA IOH=-25mA IOL=25mA No Load No Load With exact crystal 4.5 3.5 2.5 2.5 1.5 VDD-0.4 2.4 0.4 19 10 7 0 AC CHARACTERISTICS Input Clock or Crystal Frequency 14.31818 MHz Input Crystal Accuracy 30 ppm Input Clock Duty Cycle, 14.31818MHz Time above 2.5V 20 80 % 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 Time above 1.5V 45 50 55 % Absolute Clock Period Jitter, 14.318 MHz output -400 250 400 ps Absolute Clock Period Jitter, 20, 25 MHz outputs -300 150 300 ps One Sigma Clock Period Jitter All outputs 70 ps 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. Typical values are at 25°C. 3. Provided an exact clock input or a properly tuned crystal is used as the reference. 3 Revision 121598 Printed 11/15/00 MicroClock Division of ICS • 525 Race Street • San Jose • CA • 95126•(408)295-9800tel•(408)295-9818fax MDS 2014A B MK2014A Fast Ethernet Clock Source I C R O C LOC K Package Outline and Package Dimensions 8 pin SOIC E Symbol A b D E H e h Q H Pin 1 h x 45° D Q Millimeters Min Max 1.397 1.778 0.330 0.483 4.699 5.080 3.810 4.064 5.715 6.223 1.27 BSC 0.381 0.102 0.254 A c e Inches Min Max 0.055 0.070 0.013 0.019 0.185 0.200 0.150 0.160 0.225 0.245 .050 BSC 0.015 0.004 0.01 b Ordering Information Part/Order Number MK2014A MK2014ATR Marking MK2014A MK2014A Package 8 pin SOIC Add tape and reel Temperature 0 to 70 C 0 to 70 C 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. 4 Revision 121598 Printed 11/15/00 MicroClock Division of ICS • 525 Race Street • San Jose • CA • 95126•(408)295-9800tel•(408)295-9818fax MDS 2014A B