MK2011 Fast Ethernet Clock Source I C R O C LOC K Description Features The MK2011 is the ideal way to generate clocks for Fast Ethernet cards or systems. It provides 20MHz, 25MHz, and 50MHz clocks. In an 8 pin SOIC, the MK2011 can save component count, board space, and cost over surface mount crystals and oscillators, and increase reliability by eliminating two or three mechanical devices from the board. • Packaged in 8 pin SOIC MicroClock offers many other clocks for computers and computer peripherals. Consult MicroClock when you need to remove crystals and oscillators from your board. • Input crystal or clock frequency of 20.00 MHz • Lowest jitter in the industry reliably clocks sensitive Ethernet devices. • Output clock frequencies of 20.00 MHz, 25.00 MHz, and 50.00 MHz • 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 PLL Clock Synthesis Circuitry 20.00 MHz xtal or clock Output Buffer 50 MHz Output Buffer 25 MHz Output Buffer 20 MHz X1 Crystal Oscillator X2 1 Revision 120597 Printed 11/15/00 MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax MDS 2011 B MK2011 Fast Ethernet Clock Source I C R O C LOC K Suggested Layout Pin Assignment 20.00 MHz in (crystal caps not shown) Pin 1 X1/ICLK 1 8 X2 VDD 2 7 20M GND 3 6 GND 25M 4 5 50M V 2 7 3 6 4 5 G 33Ω (optional) 25MHz out Pin Descriptions Number 1 2 3 4 5 6 7 8 Name X1/ICLK VDD GND 25M 50M GND 20M X2 Type I P P O O P O O 20MHz out 33Ω (optional) 0.1µF 8 pin SOIC 8 33Ω (optional) 50MHz out Description Crystal Connection. Connect to a 20.000 MHz crystal or clock. Connect to +5V. Connect to ground. 25.000 MHz clock output. 50.000 MHz clock output. Connect to ground. 20.000 MHz buffered crystal clock output. Crystal Connection to a 20.000 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. For a crystal input, one 22pF load capacitor should be connected to each of the X1 and X2 pins and ground, and a parallel resonant 20.000 MHz, 16pF load, crystal is recommended. The frequency tolerance of the crystal should be 50ppm or better. For a clock input, connect to X1 and leave X2 unconnected. A decoupling capacitor of 0.1µF should be connected between VDD and GND on pins 2 and 3, and 33Ω terminating resistors should be used on clock outputs with traces longer than 1 inch. 2 Revision 120597 Printed 11/15/00 MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax MDS 2011 B I C R O C LOC K MK2011 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 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 20.0000 MHz Input Crystal Accuracy 50 ppm Input Clock Duty Cycle, 20.000MHz 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, 20 MHz output -400 250 400 ps Absolute Clock Period Jitter, 50, 25 MHz clocks -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 Revision 120597 Printed 11/15/00 MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax MDS 2011 B MK2011 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 1.7272 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 0.068 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 MK2011S MK2011STR Marking MK2011S MK2011S Package 8 pin SOIC Add tape and reel Temperature 0-70°C 0-70°C While the information presented herein has been checked for both accuracy and reliability, MicroClock Incorporated 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 MicroClock. MicroClock reserves the right to change any circuitry or specifications without notice. MicroClock does not authorize or warrant any MicroClock product for use in life support devices or critical medical instruments. 4 Revision 120597 Printed 11/15/00 MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax MDS 2011 B