IMISC401 SYSTEM CLOCK CHIP March 1993 PRODUCT FEATURES w@ Generates all Essential Clock Signals for the Motherboards w 4V to 7V Operating Supply Range mw Supports 8086, 80286, 80386 and 80486 Based Designs m@ Integrates Keyboard Clock, CPU Clocks and Buffered 14.318 MHz Output w Wide Range of Selectable Output Frequencies Including 88, 80, 66.6, 50, 40, 32, 24, 16, and 8 MHz @ Tri-State Outputs = 1 NS Maximum Skew Between MCLK and MCLK/2 CPU Clock Outputs m Single Low Cost Crystal (14.318 MHz) Used as Reference Frequency m@ Two Independent Clock Generators g Glitch-Free Switching for Both Clock Generators @ 50% Duty Cycle m Power Down Mode for Low Power Consumption gw TTL or CMOS Compatible Outputs with 12 mA Drive Capability m Low, Short and Long Term Jitter m@ 20 PDIP and 20 Pin SSOP (209 Mil Body) Package Options CLKI4 14.318 MHz 14.318 MHz PDI vcoint KCLK 7.159 MHz so s\ CLOCK GEN MCLK2 1 S2 MGLK1 Ts PD2 voon2 CLOCK GEN 32 MHz 16 MHz 2 IMISC401 BLOCK DIAGRAM WI ax INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571 CMOS LSI PLL FREQUENCY SYNTHESIZER PRODUCT DESCRIPTION The IMISC401 is a clock chip for Motherboards. The IMISC401 includes two independent VCOs and uses a single 14.318 MHz external crystal to generate all essential clock signals. The IMISC401 is designed to generate CPU clock options of 88 MHz, 80 MHz, 66.6 MHz, 50 MHz, 40 MHz, 32 MHz, 24 MHz and 16 MHz as well as the resultant frequencies from dividing these frequencies by 2, giving flexibility to the user. The frequency selection on the CPU clock outputs is determined by the SO-S2 pins. The user can use the 32 MHz and 16 MHz as fixed frequencies and select the variable frequencies using SO-S2 pins for the CPU clock. MCLK1 output frequency is half of MCLk2. Both VCOs can be turned off in the standby mode, reducing the current consumption to a few micro amperes. In the standby mode all outputs except 14.318 MHz output are low and both phase detectors are tri-stated. APPLICATIONS IMISC401 eliminates the need for multiple oscillators and generates all the essential clock signals for the Personal Computer Motherboards. Supports 8086, 80286, 80386SX, 80386DX and 80486 based designs. IMISC401 can be used with laptop or notebook computers to save power by running the system slower then normal CPU speeds or completely disabling the clocks in standby mode. Page 1IMISC401 SYSTEM CLOCK CHIP Xin, Xout - These pins form an on-chip reference oscillator when connected to terminals of an external parallel resonant crystal (nominally 14.31818 MHz). Xin may also serve as input for an externally generated reference signal. $0, $1 and S2 - Frequency select inputs. These inputs control the MCLK2 frequency selection. SO-S2 inputs control the CPU clock frequencies. All these inputs have internal pull-ups. Table 1 shows the output frequency selection conditions. TS - Tri-State input pin. When high, all outputs are Tri-Stated. When low outputs are enabled. This pin has an internal pull-down. MCLK2 - Master clock output. Programmable output frequencies can be selected using S0-S2 inputs shown on Table 1. MCLK1 - MCLK2 divided by two output. Output skew from MCLK2 is less then 2ns. 32 MHz - 32 MHz ISA clock output. 16 MHz - 16 MHz AT Bus Clock output. 14.318 MHz - 14.31818 MHz output. Buffered output of on-chip reference oscillator or externally provided reference. 7.159 MHz - 7.159 MHz output. This output is the divided by 2 result of 14.318 MHz output. It can be used as keyboard clock. Page 2 PIN DESCRIPTION vcoini and VCOin2 - VCO inputs for the internal VCOs. For typical applications, these inputs are shorted to the respective PD outputs to form the loop filters. PD1 and PD2 - These are the phase detector outputs for the clock generators. They are single-ended, tri-state outputs for use as loop error signal. A 0.1uF capacitor to ground should be connected from each pin to form the loop filter. VSS - Circuit ground. VDD - Positive power supply. MCLK2 FREQUENCY SELECTION INPUTS OUTPUT $2 $1 So MCLK2 0 0 0 24 MHz 0 0 1 32 MHz 0 1 ) 40 MHz 0 1 1 50 MHz 1 0 0 66.6 MHz 1 0 1 80 MHz 1 1 0 88 MHz 1 1 1 Power Down TABLE 1: When Power Down address is selected, all VCOs are turned off and the device goes to standby mode. All outputs except 14.318 MHz output are set to low. Phase detectors are in tri-state mode. INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571Ton SYSTEM CLOCK CHIP ee 2-10 71-17 e BLOCK DIAGRAM XxOUT 152 [ {2} Lo | > {20) 14.318 MHz a 14.318 IM | MHz XIN OY 1 M462 R 2 2 (4) {1} - Tig 4) 7.150 MHz | 1 IN COUNTER | 1 2 <} @) vcoint vco} wa 2 2 TS (0) meu Af a > 13) MCLK2 1 Ts @) PHASE DET {}+___( PD2 vi N25 vob Lp (2) vob VAT2 MH 2k mY cone von . 2f~, 32 Me ; [lg 2 2P2 (8) 18 MHz IMI SC401 BLOCK DIAGRAM INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571 ST. Page 3IMISC401 SYSTEM CLOCK CHIP MAXIMUM RATINGS This device contains circuitry to protect the inputs against damage due to high static voltages or electric field; however, precautions should be taken to avoid Voltage Relative to VSS : -0.3V to 7V vi : . application of any voltage higher than the maximum Voltage Relative to VDD : 0.3V rated voltages to this circuit. For proper operation, Vin : and Vout should be constrained to the range: Storage Temperature : -65C to +150C Vss < (Vin or Vout) < VDD Ambient Temperature: -55C to +155C Unused inputs must always be tied to an appropriate Recommended Operating Range: 4V -7V logic voltage level (either Vss or VDD). ELECTRICAL CHARACTERISTICS Characteristic Symbol Min Typ Max Units Input Low Voltage VIL - - 0.8 Vde Input High Voltage VIH 2.0 - - Vdc Input Low Current HL . . 5 uA With Pul-up or Pull-down +50 input High Current WH - _ 5 UA With pull-up or pull-down +50 Output Low Voltage loL = 12mA VOL - - 0.4 Vde Output High Voltage loH= 12mA VOH 2.4 - - Vdc Tri-State Leakage Current loz ~ 10 uA Static Supply Current IDD - - 10 uA Dynamic Supply Current icc - - 0.3 mA/MHz/VCO mA Short Circuit Current Isc 25 - mA VDD = 5V +10%, TA = 0C to +70C SWITCHING CHARACTERISTICS Characteristic Symbol Min Typ Max Units Output Rise and Fall Time tTLH, tTHL - 2 ns Output Enable TS to All Outputs u 35 ns Duty Cycle All Outputs 45/55 50/50 45/55 % Jitter one sigma 100 ps Input Rise and Fall Times OSCIN {TLH, tTHL - 3 1 us VDD = 5V +10%, TA = 0C to +70C Page 4 INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571IMISC401 SYSTEM CLOCK CHIP TIMING DIAGRAMS {1 t3 1 def | S0-S2 a T t MCLK OUTPUTS TAL ro Changing Outputs t : Current cycie time t1: time to first positive edge after address change t2: Output high time. t3 = 4t t3: Lock time. 7ms max tz ar TS _CCUti<OCOCSCSCSCNC;*#s ANY OUTPUT i-Z INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. Page 5 MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-657 1IMISC401 SYSTEM CLOCK CHIP CONNECTION DIAGRAMS PLASTIC DIP PACKAGE SSOP PACKAGE Xf Xin q10 20 [> 14.318 MHz Xin qd1iO 20 > 14.318 MHz Xout qJ2 19 & VDD Xout q2 19 > VDD vss Pak 18 b ppD2 vss <3 18 > pp2 so Js 16 [> 16 MHz $0 ds 16 b> 16MHe vcoint = 6 15 32 MHz vcoint Je 15 [> 32MHz PDI q7 14 fb vss PDI d7 14> vss VoD <8 19 B MCLK2 vop qs 13 f> MCLK2 $1 q9 12D S2 $1 do 12 P S2 MCLK 1 10 1p TS MCLIC1 a10 14 Ts EXTERNAL CONNECTIONS C1 14.318 MHz XTAL IN 14.318 MHz R CON XTAL OUT VDD 10 pt C2 VSS PD2 10 pt 7.159 MHZ vCOin2 1 SO 16 MHz vcoinl 32 MHz C3 PD1 vss VDD MCLK2 $1 $2 MCLK1 TS DIP-4 12101 IMISC401 Page 6 INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571IMISC401 cw an E2 AAANAAAAAA LA | 20 nN t E D E1 | erred Bal be ! | Ss el sls, 20 PLASTIC SKINNY DIP (300 mil narrow body) AARAR AA + TT HH no! | >| be > HHA SAA veya (* alte a fe Ae SSOP PACKAGE dt J \e INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571 SYSTEM CLOCK CHIP PACKAGE DRAWINGS AND DIMENSIONS 20 PIN SKINNY PLASTIC DiP DIMENSIONS INCHES MILLIMETERS SYMBOL MIN | NOM | MAX |] MIN | NOM | MAX A 0.145 - 0.155 | 3.68 - 3.93 Al 0.020 - - 0.51 - - B 0.016 | 0.018 | 0.020 | 0.40 | 0.45 | 0.50 Bt 0.056 | 0.059 | 0.062 | 1.47 1.52 1.57 B2 0.046 | 0.049 | 0.052 | 1.17 1.24 1.32 Cc 0.008 | 0.010 | 0.012 | 0.20 | 0.25 | 0.30 D 1.028 | 1.030 | 1.032 | 26.11 | 26.16 | 26.21 E 0.298 - 0.302 | 7.57 - 7.87 E1 0.248 | 0.250 | 0.252 | 6.30 6.35 | 6.40 E2 0.335 | 0.345 | 0.355 | 8.51 8.76 | 9.01 e1 0.100 BSC 2.54 BSC 0.128 | 0.130 | 0.132 | 3.25 | 3.30 | 3.35 a 0 7 15 0 7 15 Qi 0.059 | 0.060 | 0.061 | 1.50 1.53 1.55 Q2 0.128 | 0.130 | 0.132 | 3.25 | 3.30 | 3.35 Ss 0.063 | 0.065 | 0.067 | 1.60 1.65 1.70 20 PIN SSOP OUTLINE DIMENSIONS INCHES MILLIMETERS SYMBOL MIN | NOM | MAX | MIN | NOM | MAX A 0.068 | 0.073 | 0.078 | 1.73 1.86 1.99 Al 0.002 | 0.005 | 0.008 | 0.05 | 0.13 | 0.21 A2 0.066 | 0.068 | 0.070 | 1.68 1.73 1.78 B 0.010 | 0.012 | 0.015 | 0.25 | 0.30 | 0.38 Cc 0.005 | 0.006 | 0.009 | 0.13 | 0.15 | 0.22 D 0.278 | 0.284 | 0.289 | 7.07 | 7.20 | 7.33 E 0.205 | 0.209 | 0.212 | 5.20 5.30 | 5.38 e 0.0256 BSC 0.65 BSC H 0.301 | 0.307 | 0.311 | 7.65 | 7.80 | 7.90 a 0 4 8 0 4 8 L 0.022 | 0.030 | 0.037 | 0.55 0.75 | 0.95 Page 7IMISC401 SYSTEM CLOCK CHIP ORDERING INFORMATION Part Number Package Type Production Flow IMISC401xPB Plastic Dip Commercial, 0C to +70C IMISC401xXB SSOP Commercial, 0C to +70C Note: The "x" following the IM! Device Number denotes the device revision. The ordering part number is formed by a combination of device number, device revision, package style, and screening as shown below. Marking: Example: IMI $C401xPB Date Code, Lot # IMISC401xPB ee B = Commercial, 0C to +70C Package P = Plastic Dip X = Small Outline Revision IM! Device Number Page 8 INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571