IMISC403 SYSTEM CLOCK CHIP a a A May 1993 PRODUCT FEATURES m@ Generates All Essential Clock Signals for the Motherboards w 4V to 7V Operating Supply Range m Supports 80286, 80386 and 80486 Based Designs g integrates Keyboard Clock, CPU Clocks and Buffered 14.318 MHz Output m Wide Range of Selectable Output Frequencies Including 88, 80, 66.6, 50, 40, 32, 24, 16 and 8 MHz @ Tri-State Outputs gw Single, Low Cost Crystal (14.318 MHz) Used as Reference Frequency Two Independent Clock Generators B Glitch-Free Switching for Both Clock Generators w 50% Duty Cycle m Power Down Mode for Low Power Consumption w TFL or CMOS Compatible Outputs with 12 mA Drive Capability @ Low, Short and Long Term Jitter m 20 PDIP and 20 Pin SSOP (209 Mil Body) Package Options CLK14 14.318 MHz 14.318 MHz KCLK Pot 7.150 vooint s1 CLOCK GEN 1 Ts Pde 32 MHz 16 MHz CLOCK GEN 2 vcoin2 IMISC403 BLOCK DIAGRAM INTERNATIONAL MICROCIACUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571 CMOS LS/ PLL FREQUENCY SYNTHESIZER PRODUCT DESCRIPTION The IMISC403 is a clock chip for Motherboards. The IMISC403 includes two independent VCOs and uses a single 14.318 MHz external crystal to generate all essential clock signals. The IMISC403 is designed to generate CPU clock options of 88 MHz, 80 MHz, 66.6 MHz, 50 MHz, 40 MHz, 32 MHz, 24 MHz, 16 MHz and 8 MHz, giving flexibility to the user. The frequency selection on the CPU clock outputs is determined by the SO-S3 pins. The user can use the 32 MHz and 16 MHz as fixed frequencies and select the variable frequencies using SO-S3 pins for the CPU clock. S3 pin selects single or double frequency on the MCLK2 output determined by S0-S2. Both VCO's can be turned off in the standby mode, reducing the current consumption to a few microamperes. In the standby mode, all outputs except 14.318 MHz output are low and both phase detectors are tri-stated. APPLICATIONS IM!ISC403 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. IMISC403 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 1IMISC403 SYSTEM CLOCK CHIP PIN DESCRIPTION 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, $2, and S3 - Frequency select inputs. These inputs control the MCLK2 frequency selection. SO-S2 inputs control the CPU clock frequencies. S3 selects single or double frequency determined by SO-S2. All these inputs have internal pull-ups. Tabie 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 SO-S3 inputs shown in Table 1. 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. VCOin1 and VCOin2 - VCO inputs for the internal VCOs. For typical applications, these inputs are Page 2 shorted to the respective PD outputs to form the loop fitters. 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 fitter. VSS - Circuit ground. VDD - Positive power supply. MCLK2 FREQUENCY SELECTION INPUTS MCLK2 OUTPUT $2 $1 SO $3=0 $3=1 0 0 0 12 MHz 24 MHz 0 0 1 16 MHz 32 MHz 0 1 0 20 MHz 40 MHz 0 1 1 25 MHz 50 MHz 1 0 0 33.3 MHz 66.6 MHz 1 0 1 40 MHz 80 MHz 1 1 0 44 MHZ 88 MHz 1 1 1 TEST Donen 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 : 408-263-6571IMISC403 SYSTEM CLOCK CHIP BLOCK DIAGRAM [ xo (2) 1 [02 2 MS: G0) 14.318 MHz CJ 14318 ; 1M +g L XIN C) 1 [Dez R 2 Mm, ) 7.150 MHz . | L i 28 so st $2 PHASE 1 /}_ 1 2 | @) vein Non 1 83 TS PHASE on rs 2 <I 17) VOOin2 vom yoo 2 Pa 15) 2 MHz vo 1 vss 2 Mm 3 O) 18MHz vss f, witee IM! SC403 BLOCK DIAGRAM INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. Page 3 MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571IMISC403 SYSTEM CLOCK CHIP CECE acre a ap ago Voltage Relative to VSS : -0.3V to 7V field; however, precautions should be taken to avoid application of any voltage higher than the maximum Voltage Relative to VDD : 0.3V rated voltages to this circuit. For proper operation, Vin : 3 and Vout should be constrained to the range: Storage Temperature: -65C to 150C Ambient Temperature: -55C to 125C VSS < (Vin or Vout) < VDD Unused inputs must always be tied to an appropriate Recommended Operating Range: 4V - 7V logic voltage level (either Vss or VOD). ELECTRICAL CHARACTERISTICS Characteristic Symbol Min Typ Max Units Input Low Voltage Vit - - 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 (IH - . S uA With pull-up or pull-down +50 Output Low Voltage . _ lol = 12mA VOL 0.4 Vdc Output High Voltage 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 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 : 408-263-6571IMISC403 SYSTEM CLOCK CHIP TIMING DIAGRAMS | 1 * MCLK OUTPUTS i : Changing Outputs t: Current cycle time t1: time to first positive edge after address change t2: Output high time. t3 = 4t t3: Lock time. 7ms max TS _OCUst<(iOSOSOSOCOCOC; ANY OUTPUT TILLY LS LIT Hi-z INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. Page 5 MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571IMISC403 SYSTEM CLOCK CHIP CONNECTION DIAGRAMS PLASTIC DIP PACKAGE Xin 10 ~~ ab 14318 MHz Xout de 10 b vob vss 3 18 b ppe 7.159MHz <4 17 b veoin2 $0 ds 16 > 16 MHz vcoint je 15 [> 32MHz PDI d7 14 b vss VOD de 13 fb MCLK2 $1 jo 12 b $2 $3 <j 10 1p TS SSOP PACKAGE Xin d1O ~~ 20 b 14318 MHz Xout q2 19 > VDD vss <3 18D PD2 7.159MHz <4 17 B VCOin2 so a5 16 > 16 MHz vcoin1 a6 15 [> 32MHz PD1 q7 14> vss vpb qs 13 D> MCLK2 $1 qs 12 > S2 $3 10 11 pb Ts EXTERNAL CONNECTIONS 14.318 MHz C1 XTALIN 14.318 MHz XTAL OUT VDD 10 pf C2 vss PD2 10 pf 7.159 MHZ voOin2 so 16 MHz vcoint 32 MHz C3 PD1 VSS VOD MCLK2 S1 S2 $3 TS 12/31/91 DIP-5 IMISC403 cs C7 7 UF uF R CON C4 1uF 7.159 MHz Page 6 INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571IMISC-403 SYSTEM CLOCK CHIP PACKAGE DRAWINGS AND DIMENSIONS 20 PIN SKINNY PLASTIC DIP DIMENSIONS INCHES MILLIMETERS SYMBOL MIN | NOM | MAX | MIN | NOM | MAX eo A 0.145| - |0.155| 3.68 - 3.93 he a Al 0.020| - - 0.51 - - B 0.016 | 0.018 | 0.020 | 0.40 | 0.45 | 0.50 AAAAAAAARA B1 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 fi Ss 0 4 Cc 0.008 | 0.010 | 0.012 | 0.20 | 0.25 | 0.30 SUV TUE D 1.028 | 1.030 | 1.032 | 26.11 | 26.16 | 26.21 : ae a2 E 0.208 | - | 0.302 | 7.57 - 7.67 Qi a E1 0.248 | 0.250 | 0.252 | 6.30 | 6.35 | 6.40 T pei te E2 | 0.335 | 0.345 | 0.355] 8.51 | 8.76 | 9.01 | et 0.100 BSC 2.54 BSC ~ a || lees L L 0.128 | 0.130 | 0.132 | 3.25 | 3.30 | 3.35 Set aK a o | 7 | 15 | of | 7 | 415 20 PLASTIC SKINNY DIP Qi 0.059 | 0.060 | 0.061 | 1.50 | 1.53 | 1.55 (300 mil narrow body) 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 c INCHES MILLIMETERS WE SYMBOL AARAA AA af Fi MIN | NOM | MAX | MIN | NOM | MAX f tr A 0.068 | 0.073 | 0.078 | 1.73 1.86 1.99 EH RN 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 3 a Cc 0.005 | 0.006 | 0.009 | 0.13 | 0.15 | 0.22 yer D 0.278 | 0.284 | 0.289 | 7.07 7.20 7.33 vo E 0.205 | 0.209 | 0.212 | 5.20 | 5.30 | 5.38 AK > kK Ba e 0.0256 BSC 0.65 BSC ssor PACKAGE 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 INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. Page7 MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571IMISC403 SYSTEM CLOCK CHIP ORDERING INFORMATION Part Number Package Type Production Flow IMISC403xPB Plastic Dip Commercial, 0C to +70C IMISC403xXB SSOP Commercial, 0C to +70C Note: The "x" following the IMI 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 S$C403xPB Date Code, Lot # IMISC403xPB La B = Commercial, 0C to +70C _ Package P = Plastic Dip X = SSOP Revision IMI Device Number Page 8 INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571