MK1432/MK1434 Green PC and Local Bus Clock Source Description Features The MK1432 and MK1434 are low cost, high performance triple clock synthesizers for green PC and local bus desktop and notebook applications. Using analog Phase-Locked Loop (PLL) techniques, the devices accept a 14.318 MHz crystal input to produce multiple output clocks up to 100 MHz. They provide selectable 2XCPU and CPU, selectable local bus clock, ISA clock, and one fixed peripheral clock. The chips support PCI and VL buses. The fixed clock is either 24MHz or 40MHz. The devices can operate at 5V or 3.3V up to and including 80MHz on the 2XCPU clock. • Packaged in 16 pin narrow (150 mil) SOIC • Supports all Pentium™ Processor timing specs • Supports synchronous and asynchronous local bus • Selectable local bus frequencies of 25, 33, or 50MHz • SCSI or VL bus 40MHz clock on MK1434 • Floppy or super I/O clock on MK1432 • Single Power Saving pin switches to low power mode (for 486 and Pentium) • 5V or 3.3V (up to 80MHz) operation • Smooth transitions for Pentium and 486 based Green PC • Low skew (<250ps) Pentium compatible 2X and 1X outputs • Duty cycle of 45/55 up to 100 MHz • 25mA output drive capability at TTL levels • Compatible with all popular microprocessors • Packaged in 16 pin narrow SOIC • For Early Clock support, consult MicroClock The Power Saving pin causes the CPU clocks to smoothly transition to 33.33 MHz for Pentiums, and 16.67 MHz for 486DX4. In addition, a single pin can be made to slow DX2s to 8 MHz. Block Diagram VDD GND Output Buffer 2XCPU Output Buffer CPU Local Bus Clock Output Buffer BCLK Fixed Clock Output Buffer 40.00 (MK1434) or 24.00 MHz (MK1432) Output Buffer 14.318 MHz FS0 FS1 FS2 CPU Clocks ÷2 PS BCLKS X1 Crystal Oscillator 14.318 MHz crystal X2 MDS 1432 G 1 Revision 060101 Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295-9800 • www.icst.com MK1432/MK1434 Green PC and Local Bus Clock Source Pin Assignment FS2 1 X2 2 X1 3 VDD 4 GND 5 BCLK 6 24M 7 PS 8 16 15 14 13 12 11 10 9 FS1 2XCPU CPU VDD GND 14.3M FS0 BCLKS CPU Clock Decoding Table (in MHz) PS 1 1 1 1 1 1 1 1 0 FS2 X2 X1 VDD GND BCLK 40M PS F S 2 F S 1 F S 0 2XCPU CPU 0 0 0 16.00 8.00 0 0 1 100.00 note 350.00 note3 0 1 0 80.00 40.00 0 1 1 75.00 37.50 1 0 0 40.00 20.00 1 0 1 50.00 25.00 1 1 0 66.66 33.33 1 1 1 60.00 30.00 X X X 33.33 16.67 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 FS1 2XCPU CPU VDD GND 14.3M FS0 BCLKS Local Bus Clock Decoding Table (in MHz) BCLKS 0 M 1 BCLK (MHz) 25.00 33.33 50.00 Notes: 1. Actual frequencies are within 0.05% of those shown. 2. Transitions between mean frequencies on any CPU pin are smooth, and do not violate Intel’s 0.1% per cycle specification. 3. These selections are not guaranteed to operate at 3V. 4. M = mid level. Leave pin tri-stated, unconnected, or floating to select this level. 5. X = don’t care (either 0 or 1). Pin Descriptions 1432 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1434 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Name FS2 X2 X1 VDD GND BCLK 24M 40M PS BCLKS FS0 14.3M GND VDD CPU 2XCPU FS1 Type I O I P P O O O I TI I O P P O O I Description Select 2 for 2XCPU and CPU frequencies. See table above. Internal Pull-Up. Crystal connection. Connect to 14.31818 MHz crystal. Crystal connection. Connect to 14.31818 MHz crystal or clock. Connect to +5V or 3.3V. Must be same voltage as pin 13. Connect to ground. Local Bus Clock output. See table above. 24.00 MHz clock output (MK1432 only). 40.00 MHz clock output (MK1434 only). Power Saving pin. Smoothly changes CPU to/from 33.33 and 16.67 MHz. IPU. Local Bus Clock Select pin. See table above. Select 0 for 2XCPU and CPU frequencies. See table above. Internal Pull-Up. 14.318 MHz Reference Clock Output. Connect to ground. Connect to +5V or 3.3V. Must be same voltage as pin 4. CPU Clock output. See table above for frequencies. 2X CPU Clock output. See table above for frequencies. Select 1 for 2XCPU and CPU frequencies. See table above. Internal Pull-Up. Key: TI = Tri-level Input, I = Input, O = output, P = power supply connection MDS 1432 G 2 Revision 060101 Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295-9800 • www.icst.com MK1432/MK1434 Green PC and Local Bus Clock Source Electrical Specifications Parameter Conditions Minimum Typical Maximum Units 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 20 seconds 260 °C Storage temperature -65 150 °C DC CHARACTERISTICS (VDD = 5V unless noted) Operating Voltage, VDD 3.0 5.5 V Input High Voltage, VIH 2 V Input Low Voltage, VIL 0.8 V Mid-level pin Input High Voltage, VIH Pin 9 only VDD-0.5 V Mid-level pin Input Low Voltage, VIL Pin 9 only 0.5 V Output High Voltage, VOH IOH=-25mA 2.4 V Output Low Voltage, VOL IOL=25mA 0.4 V Output High Voltage, VOH VDD=3.3V, IOH=-8mA 2.4 V Output Low Voltage, VOL VDD=3.3V, IOL=8mA 0.4 V Operating Supply Current, IDD No Load, note 2 40 mA Operating Supply Current, IDDPS No Load, PS=0 27 mA Short Circuit Current Each output (except X2) ±100 mA On-Chip Pull-up Resistor Pins 1, 8, 10, 16 250 kΩ Input Capacitance 7 pF AC CHARACTERISTICS (VDD = 5V unless noted) Input Frequency 14.31818 MHz 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 45 49 to 51 55 % Cycle to Cycle Jitter, CPU Clocks 1000 ps Absolute Clock Period Jitter 14-40 MHz clocks -500 500 ps Skew of 2XCPU with respect to CPU Rising edges at 1.5V -250 0 250 ps Transition time, 33.3MHz to 66.6MHz VDD=3.3 or 5V 3 ms Transition time, 66.6MHz to 33.3MHz VDD=3.3 or 5V 2 ms 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 2XCPU clock at 66.66MHz, and BCLK at 33.33MHz External Components The MK1432/4 requires a minimum number of external components for proper operation. Decoupling capacitors of 0.1µF should be connected between VDD and GND, as close to the MK1432/4 as possible. A series termination resistor of 33Ω may be used for each clock output. The device does not require (nor do we recommend) capacitors connected to the crystal pins. The 14.31818 MHz crystal must be connected as close to the chip as possible. Recommended load capacitance for the crystal is 12pF. MDS 1432 G 3 Revision 060101 Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295-9800 • www.icst.com MK1432/MK1434 Green PC and Local Bus Clock Source Package Outline and Package Dimensions E 16 pin SOIC narrow Inches Symbol Min Max A 0.055 0.070 b 0.013 0.019 c 0.007 0.010 D 0.385 0.400 E 0.150 0.160 H 0.225 0.245 e .050 BSC h 0.016 Q 0.004 0.01 H h x 45° D A c Q e Millimeters Min Max 1.397 1.778 0.330 0.483 0.191 0.254 9.779 10.160 3.810 4.064 5.715 6.223 1.27 BSC 0.406 0.102 0.254 b Ordering Information Part/Order Number Marking Fixed Output Clock Frequency Package Temperature MK1432S MK1432S 24 MHz 16 pin SOIC 0-70°C MK1434S MK1434S 40 MHz 16 pin SOIC 0-70°C MK1432STR MK1432S - Add Tape & Reel - MK1434STR MK1434S - Add Tape & Reel - 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. Pentium™ is a registered trademark of Intel Corporation MDS 1432 G 4 Revision 060101 Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295-9800 • www.icst.com