ane Meniey SYSTEM CLOCK CHIP July 25, 1994 Preliminary PRODUCT FEATURES mw Generates CPU Clock Signals for Microprocessor Systems m Reduces Measured EMI by 10 dB Nominal m 4V to 7V Operating Supply Range m Supports 80286-, 80386-, 80486-, Pentium- and 29000-Based Designs m Wide Range of Selectable Output Frequencies Including 50, 60, 100 and 120 MHz m= Single, Low Cost Crystal Used as Reference Frequency @ Glitch-Free Switching m Power Down Mode for Low Power Consumption m= TTL or CMOS Compatible Outputs with 6 mA Drive Capability a Pin Compatible with IMISG501 and IMISG502 w 16 PDIP and 16 Pin SOIC (300 Mil Body) Package Options 3 as2 14 npcie 8 REF Tia on sie |}. kez C2 Le wpser _ 3 Le 16 a | ? so SPREAD $1 | SPECTRUN _a 8 12 PRELK 12 $sor IMISG504 BLOCK DIAGRAN INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571 CMOS LS/ SPREAD SPECTRUM CLOCK GENERATOR PRODUCT DESCRIPTION The IMISG504 is a spread spectrum clock generator specially designed for personal computers, laser printers and other digital systems. IMISG504 uses a patent pending concept to generate popular clock frequencies that are intentionally broadbanded to reduce electromagnetic interference. IMISG504 attenuates the radiated emission amplitudes from products associated with either the clock harmonics or any signals derived from the clock signals nominally 10 dB and could significantly reduce the cost of complying with the regulatory requirements. PRCLK is the broadbanded output and can be programmed to generate 50, 60, 100 and 120 MHz with SO and S11 pins. A single, low cost external crystal is required as reference frequency for the synthesizer. Output modulation function can be turned off with the SSON pin. Power down mode adds the flexibility to operate the device in a completely static mode to reduce standby currents and simplify system board tests. APPLICATIONS IMISG504 eliminates the need for muitiple oscillators and generates the CPU clock signals for personal computers, laser printers and other digital systems. Supports 8086-, 80286-, 80386-, 80486-, Pentium- and 29000-based designs. IMISG504 can be used with laptop or notebook computers to save power by running the system slower than normal CPU speeds or completely disabling the clocks in standby mode. Page 1IMISG504 SYSTEM CLOCK CHIP Oscin, Oscout - These pins form an on-chip reference oscillator when connected to terminals of an external 44,2 MHz third overtone parallel resonant crystal. OSCin may also serve as an input for an externally generated CMOS level or AC coupled reference signal. SO, and S1 - Frequency select inputs. These inputs contro! the PRCLK frequency selection. SO-S1 inputs control the CPU clock frequencies. All these inputs have internal pull-downs. Table 1 shows the output frequency selection conditions. TS - Controls power down and Tri-State Mode selection. When high, $1 input controls the mode selection as shown in Table 1 and Table 2. When low, device operates in normal mode. This pin has an internal pull-down. MPSEL - Controls MPCLK output frequency selections. Tabie 2 shows the selected frequencies for MPCLK. This input has an intemal pull-up. SSON - This pin controls the spread spectrum function. When low, PRCLK is modulated. When high, spreading is turned off. This pin has an internai pull-up. LF1 - This is the control output for the clock generator. It is a single-ended, tri-state output. Component connections are shown in Figure 1. EQUENCY SELECTION OUTPUT Ts $1 $0 PRCLK 0 0 0 50 MHz 0 0 1 100 MHz 0 1 0 60 MHz 0 1 1 120 MHz { 0 0 0; Power Down 1 0 1 1; Power Down 1 1 0 TEST 1 1 1 Hi-Z TABLE 1: When Power Down address is selected, the VCO is tumed off and the device goes to standby mode. Phase detector is in tri-state mode. Page 2 PIN DESCRIPTION MPCLK - This is a nonmodulated output. This output can be programmed to be 3.7 MHz or 11.06 MHz. The selection of these frequencies are controlled by the MPSEL pin shown in Table 1. PRCLK - Output from the spread spectrum clock generator. Frequency selection is shown in Table 1. When the SSON pin is high, outputs are not modulated. When SSON is low, spread spectrum function is enabled. VSS - Circuit ground. VDD - Positive power supply. AVSS - Analog circuit ground. AVDD - Analog positive power supply. lF ek R2 m= 330pf C1 2200 pf T C2 FIGURE 1 OUTPUT so MPCLK 0 0 xX xX 3.7 MHz 0 1 xX xX 11.06 MHz 1 x 0 0 0; Power Down 1 X 0 1 1; Power Down 1 x 1 0 TEST 1 Xx 1 1 Hi-Z TABLE 1: When Power Down address is selected, the VCO is tumed off and the device goes to standby mode. Phase detector is in tri-state mode. INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571IN ery 0%: SYSTEM CLOCK CHIP This device contains circuitry to protect the inputs MAXIMUM RATINGS against damage due to high static voltages or electric 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 VD: 0.3V rated voltages to this circuit. For proper operation, Vin Storage Temperature: -65C to 150C and Vout should be constrained to the range: Ambient Temperature: 0C to 70C Vss < (Vin or Vout) < VDD Recommended Operating Range: 4.5 - 5.5V All inputs are tied high or low internally. ELECTRICAL CHARA Input Low Voltage VIL - - 0.8 "Vide Input High Voltage VIH 2.0 - - Vdc Input Low Current 10 With Pull-up It - - 100 HA Input High Current 10 With Pull-down IH 400 HA Output Low Voltage loL = 6mA VOL - - 0.4 Vde Output High Voltage lOH = 6mA VOH 2.5 - - Vde Tri-State Leakage Current loz - - 10 pA Static Supply Current IDD - - 250 HA Dynamic Supply loc - 25 30 mA Current Short Circuit Current Isc 25 - - mA VDD = 5V +10%, TA = 0C to 70C INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. Page 3 MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571 ~IMISG504 SYSTEM CLOCK CHIP SWITCHING CHARACTERISTICS & s Output Rise and Fall Time Measured at 10% - 90% of Vop | {TLH: tTHL - - 5 ns Output Rise and Fail Time Measured at 0.8V - 2.0V ELH, tTHL - - TBD ns Output Duty Cycles TsymF1 - - 45/55 % Jitter One Sigma tits - - 2 % of Fout VDD = 5V +10%, TA = 0C to 70C, CL = 15pF OSCILLATOR CHARACTERISTICS Transconductance gm 20 80 180 millimhos @ 44.2 MHz Output Impedance Zo - 200 800 ohms @ 44.2 MHz Input Capacitance Ci 8 13 18 pf - Output Capacitance Co 3 6 9 pf - DC Bias Voltage VB 1.5 VDD/2 3.5 Volt - Start-up Time ts - - 2 ms @ VDD = 4.5V VCO CHARACTERIS VCO Gain 35 55 65 MHz/volt AF/AV Measured with VCO Control at 2V - 3V Phase Detector Gain 100 145 200 yA Page 4 INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571MUReRIey CONNECTION DIAGRAMS PDIP PACKAGE VDD dio ~ wb Ts oscin <2 15 P vDD OScout <3 14 MPCLK _ vss <4 13> vss MPSEL <J5 12 PRCLK avoD <6 11D avss So 7 10> LF1 s1 8 9 sson iS) SYSTEM CLOCK CHIP OIC PACKAGE vop dio ~ tb Ts OSCin <2 18 > voo oscout G3 14> MPCLK vss 7 13 > vss MPSEL 5 12> PRCLK AVDD <6 11 avss So a7 10 [> LF $1 as 9 SSON PACKAGE DRAWING AND DIMENSIONS oo som eo me Soot ae eM SOIC PACKAGE INTERNATIONAL MICGROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571 SYMBOL INCHES MILLIMETERS MIN NOM MAX MIN | NOM | MAX 0.097 0.101 0.104 2.46 | 2.56 | 2.64 0.0020 0.009 0.0015 0.060 | 0.22 | 0.38 0.090 0.092 0.111 2.29 | 2.34 | 2.39 0.014 0.016 0.019 0.35 | 0.41 | 0.48 0.0091 0.010 0.0125 0.23 | 0.25 | 0.32 0.399 0.407 0.412 10.13 | 10.34 | 10.46 0.285 0.296 0.299 7.24 | 7.52 | 7.59 0.050 BSC 1.27 BSC Page 5IMISG504 SYSTEM CLOCK CHIP EXTERNAL CONNECTIONS TU V7 DIGITAL GND PLANE l1 9 DIGITAL POWER PLANE . nnn _ <ov0o ] th 1S ol = AWALOG GND PLANE c1 o lduF ANALOGS POWER PLANE Ri <D Tr AAA 10 Ohas c19 T 22uF CHLOE Vara L oh Miz Wt = 1 16 . ts tin von 281 Tes <orne] -|| tb 3 gut mPcix Lt Set liF ups L H +_1] iss vss 23 tf 3908 Supse, parti 2 Litt lu $ avon avss 1.2 uN 7165 tt a - 1 HEADER C2L10pF 8 1110p $1 $SON 1 =v oe504 = L 2k 8 1uF <i | 2 IL 2200pF Cl NPSEL JPL, + a 330 pf Jpe ~ Soy ''o JP3 S17 Jes TESTS" 'o- <v00 | HOTEL : KEEP C3,C4,C5,C6 CLOSE TO THEIR PINS (4,11,13,10,9 RESPECTIVELY), Page 6 INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571IMISG504 SYSTEM CLOCK CHIP a 2ST al as 2 REFERENCE FREQUENCY VS OUTPUT FREQUENCIES PRCLK VS XTAL 120 + Ot Si=t So $1=0,S0=1 Ir 804 = x 60 df St=1 $0=0 rt $1=0,S0=0 20 + 0 EF Lt Lil Lett tt Deb beletan!, + + YT tT tT tT YT YT FT TFT tT + + Tt F oO Oo 7 N co +t WwW o oO oO Oo - N NN nm oO M4 oO Oo &# oO M4 +t + + w+ XTAL (MHz) INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. Page 7 MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571 SSSSerer 0 SYSTEM CLOCK CHIP ORDERING INFORMATION IMISG504xPB Plastic Dip Commercial, 0C to +70C IMISG504xXB SOoic 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: IIMi $G504xPB Date Code, Lot # IMISGS04xPB Page 8 | Flow B = Commercial, 0C to +70C Package P = Plastic Dip X= Smail Outline Revision IMI Device Number INTERNATIONAL MICROCIRCUITS INC. 525 LOS COCHES ST. MILPITAS, CA 95035 TEL :408-263-6300 FAX : 408-263-6571