Integrated Circuit Systems, Inc. 1ICS2407 ICS2409 ICS2419 ICS2439 Dual-PLL Motherboard Frequency Generator Description This ICS family of motherboard frequency generators all stem from the same basic design. They are dual-PLL (phase-locked. loop) clock generators specifically designed for motherboard applications. Metal layer and assembly options are used to generate the three separate device types in order to optimize the functionality for specific applications. All frequencies are synthesized from a single reference clock which may be generated by the on-chip crystal oscillator or an external reference clock. The CPU clock PLL is ROM-programmed to generate any of seven customer specified frequencies through selection of the address lines SCLKO-SCLK2. In the ICS2409, ICS2419 and 1CS2439 versions the SCLK3 input selects those frequencies directly or divided by two for the CPUX2 output. The CPUX2 output is then divided by two to generate the CPUCLK output. A power-down mode may be selected with the SCLK inputs to reduce standby current consumption to a few microamperes. The auxiliary (AUX) PLL generates the fixed frequencies shown in Table 1 for other system uses. A buffered reference frequency output is available on the REFOUT pin. Two non-dedicated buffers are provided on the ICS2409, ICS2419 and ICS2439 for additional drive capability without adding external buffers and their board space. Features e@ Supports 286, 386, & 486 desktop and notebook mother- board designs e Advanced ICS monolithic phase-locked loop technology for low short-term and cumulative jitter e Completely integrated - no external loop filter capacitors required e Dual-modulus prescaler permits high-speed operation with no sacrifice in accuracy Power-down mode for low standby power consumption Low-skew between CPUX2 and CPUCLK outputs (<1 nsec ) 3-volt supply capability to 85 MHz (CPUX2 output) Output enable (OE~) pin for tristate of device outputs 1CS2409, ICS2419 and ICS2439 offer 24-pin PDIP (0.3") and 24-pin SSOP (5.3mm) package options e ICS2407 offers 18-pin PDIP (0.3") and 18-pin SOIC (0.3") package options ICS2407 Simplified Block Diagram xTAL1 Crystal oT, SR 1 XTALZ Oscitator [7 wD 2 REFOUT Reference OMder REFOUT2 Frequency Ki Charge veo _\ Ly Pump > PD CPUKZ Ly pene 24MHZ, 16MHZ SCLKO SCLKI ROM SCLK2 2407/09/19/30RevB022304 C31ICS2407 ICS2409 1CS2419 ICS2439 XTALI Crystal 1CS2409 Simplified Block Diagram XTAL2 Oscillator Reference > REFOUT 7.159MHZ Phase- Ly Charge Frequency Ly Pump |__y VCO B1_IN SCLKO SCLK1 ROM SCLK2 AUX PLL {as above} B2_iN VV XTALI XTAL2 1CS2419 Simplified Block Diagram Crystal Oscillator zy Reference > > REFOUT Divider ~ SCLKO SCLK1 ROM SCLK2 SCLK23 AUX PLL (as above) B1_IN BZ_IN S > B2_OUT > > B1_OuT PMN ea1CS2407 1CS2409 ICS2419 ICS2439 XTALI XTAL2 SCLKO SCLKI SCLK2 B1_IN B2_IN Crystal Osciilator ICS2439 Simplified Block Diagram a 5ICS2407 ICS2409 ICS2419 ICS2439 Circuit Function and Application Fixed Frequencies The ICS motherboard family supplies fixed frequencies nor- mally used to provide several system functions: 32 MHz - ISA Bus Clock 24 MHz - Floppy Drives [6 MHz - AT Bus Clock Output 12 MHz - Keyboard Clock 7.149 MHz - Keyboard Clock Selectable CPU Clock Frequencies The ICS2407, ICS2409, 1CS2419 and ICS2439 are designed to generate CPU clock options ranging from 24 MHz, to 88 MHz. For added flexibility, the ICS2409, ICS2419 and 1CS2439 allow the user to select each of these frequencies divided by 2. Buffered Output Pins In addition, the 1CS2409, ICS2419 and ICS2439 provide 2 non-dedicated buffers for additional flexibility. This allows for extra drive capability without sacrificing the extra board space required for external buffers. Buffered XTALOUT In motherboard applications it may be desirable to have the 1CS2439 provide the bus clock for the rest of the system. This eliminates the need for an additional 14.31818 MHz crystal oscillator on the system, saving money as well as board space. Depending on the load, it may be judicious to buffer REFOUT when using it to provide the system clock. On the ICS2407, there are two identical outputs, REFOUT1 and REFOUT2. Power-Down Mode All three devices have been optimized for use in battery operated portables. It can be placed in a power-down mode which drops its supply current requirement below 1pA(typical). Pin Description Input Pins Frequency Reference The internal reference oscillator contains all of the passive components required. An appropriate crystal should be con- nected between XTALI (1) and XTAL2 (2). In IBM compatible applications this will typically be a [4.31818 MHz crystal. Digital Inputs SCLKO, SCLK1, SCLK2 and SCLK3 (1CS2409, ICS2419 and 02439 only) are the TTL compatible frequency select inputs for the binary code corresponding to the desired frequency. All select pins have intemal pull-up devices built in (See Table 2 foracomplete list of available frequencies). Buffer Inputs (ICS2409, ICS2419 & ICS2439) B1_IN and B2_IN (3, 7) provide additional buffering needed on a typical board design without the added cost of external components. Output Enable An output enable pin OE~allows the user to tristate the device outputs. When this pin is high, al! outputs are in tristate mode. When low, all outputs are enabled. This pin has an internal pull-down to enable all outputs when the pin is N/C. 1CS2407 Pinout 1CS2409 Pinout 1CS2439 Pinout 'C$2419 Pinout 1 | xTAL REFOUT! | 18 a | xTALI REFOuT | 25 v | xTALI REFOUT | 24 + Toxrau REFOUT | 23 2] xTaL2 YOO | 17 2 | xTAL2 B1_ouT | 23 2] xTALZ Br OuT | 23 2 | xTAL2 81 OUT | 23 3 VSS wc | 16 3 BILIN VDD 22 2 B1iN voD 22 3 B1_iN voD 22 4 AEFOUT2 16MHZ | 15, 4 VSS NC 21 4 vss NIC a 4 vSS NC ral 5 SCLKO 24MHZ | 14 s 7ASSMHZ 16MHZ 26 5 12MHZ 16MHZ | 20 5 412MHZ, 16MHZ 20 NC VSS | 13 6 SCLKO 24MHZ 1% 6 SCLKO 24MHZ 19 6 SCLKO 24MHZ 19 7 YDD CPURX2 | 12 B2_iN B2MHZ 18 7 82_IN RESERVED 18 B2_IN 32MMZ 18 8B SCLKI SCLKZ | 11 8 NG B2_QUT 7 a NC Bz_OUT vw 8 NC 82_OUT 7 g | cPucuK OE- | 70 2 vod vss | 16 9 voD vSS | 16 s VDD vss 16 19 SCLKI CPUKZ ty 1G. SCLKI CPUXZ 1S 10 SCLK1 CPUX2 15 18-Pin PDIP or SOIC | sco SCLK2 | 14 | SCLKS ScLK2 | 14 11 | SCuK3 scuk2 | 14 K-4, K-7 2 CPUCLK OE 13 2 CPUCLK oe- | 15 42 CPUCLK og. | 13 24-Pin PDIP or SSOP 24-Pin PDIP or SSOP K-5, K-9 24-Pin PDIP or SSOP K-5, K-9 K-5, K-9 C-61CS2407 ICS2409 ICS2419 1CS2439 Absolute Maximum Ratings Supply Voltage............. VDD 00. e eee eee -0.5V to +7V Input Voltage .............. A i -0.5V to Vpp + 0.5V Output Voltage ............. VOUT .. 0.0.00 eee -0.5V to Vpp + 0.5V Clamp Diode Current ........ VIK & Iok ....... +30mA Output Current per Pin....... IOUT .....--5-.-- +50mA Operating Temperature....... TO... eee eee eee OC to 70 os Storage temperature ......... TS cee eee eee eee -85C to 150 Power Dissipation. .......... PD... ec eee eee 500mW Values beyond these ratings may damage the device. This device contains circuitry to protect the inputs and outputs against damage due to high static voltages or electric fields; however, it is advised that normal precautions be taken to avoid applications of any voltage higher than themaximum rated voltages. For proper operation it is recommended that Vin and Vout be constrained to >=Vss and <=Vpp. DC Characteristics at 5 Volts Vpop (0C to +70C) PARAMETER | SYMBOL |CONDITIONS MIN MAX UNITS | Operating Voltage Range Vpp 4.5 5.5 vO Input Low Voltage VIL Vpp=5V Vss 0.8 | Vv Input High Voltage Vin Vpp=5V 2.0 VoD Vv Input Leakage Current lnm Vin=VpD - 10 HA Output Low Voltage VoL IoL=1.20mA - 0.4 v Output High Voltage Vou Ion=1.20mA 2.4 0 Vv Supply Current Ipp VCLK=40MHz - 40 mA Supply Current Ipp VCLK=88MHz - 50 mA | Internal Pull-up Current Rup Vin=0.0V 30 100 LA Internal Pull-down Current RpowNn Vin=0.0V 30 100 LA Input Pin Capacitance CIN Fco=1MHz - 8 pF ~ Output Pin Capacitance CouT Fc=1MHz - 12 pF Power-down Supply Currrent IpN Vpp=3.3V - 1 HA C-71CS2407 ICS2409 ICS2419 ICS2439 DC Characteristics at 3.3 Volts Vpp (0C to +70C) PARAMETER SYMBOL CONDITIONS MIN MAX UNITS | Operating Voltage Range Vpb 3.0 3.6 vo Input Low Voltage | VIL Vpp=3.3V__ | Vss 08 vo Input High Voltage Vin Vpp=3.3V 2.0 Vop vo Input Leakage Current tH VIN=VDD - LO HA | Output Low Voltage VoL loL=8.0mA - 0.4 Vv Output High Voltage VoH Ion=8.0mA 2.4 0 Vv Supply Current Ipp ) CPUX2=40MHz - 35 mA Supply Current Ipp CPUX2=88MHz - 25 mA | Internal Pull-up Current Rup Vin=0.0V 20 70 HA _ Internal Pull-down Current RDOWN Vin=0.0V 20 | 70 | pA | Input Pin Capacitance CIN Fco=1MHz - | 8 pF Output Pin Capacitance Cout Fo=1MHz ; - 12 pF Power-down Supply Currrent IPN Vpp=3.3V - 1 WA AC Timing Characteristics The following notes apply to all of the parameters presented in this section. 1. REFCLK = 14.31818 MHz 2. te = Ite 3. All units are in nanoseconds (ns) 4, Rise and fall time between .8 and 2.0 VDX unless otherwise stated. 5. Output pin loading = 15pF 6. Duty cycle measured at Vpp/2 unless otherwise stated. SYMBOL PARAMETER MIN MAX NOTES OUTPUT TIMING @5v Tr Rise Time - 2 | Tt Fall Time - 2 - Frequency Error | - 0.5 % Tak | Clock Skew (CPUCLK & CPUX2) - 1.0 nSec - : Duty Cycle 45 55 % _ - Output Enable to Tristate - 15 nSec | (into and out of) time | | OUTPUT TIMING @3.3v Tr Rise Time - 7 Tf Fall Time - . 3 | - Frequency Error - 0.5 % | Tak Clock Skew (CPUCLK & CPUX2) - 1.5 nSec - Duty Cycle 45 55 | & | - Output Enable to Tristate - 20 nSec (into and out of) time C-8ICS2407 ICS2409 1C$2419 ICS2439 Table 1: Fixed Output Frequencies 1CS2439 1CS2419 1CS2409 1CS2407 | 24 MHz 32 MHz 32 MHz 24 MHz 16 MHz 24 MHz 24 MHz 16 MHz 12 MHz 16 MHz 16 MHz 12 MHz 7.159 MHz Table 2: CPU Clock Frequency Selection 1S2439 | 1CS2419 1CS2409 1CS2407 SCLK3 SCLK2 SCLK1 SCLKO | pattem 001 | Pattern 001 | Pattern 409 | Pattern 407 0 0 0 0 12MHz | 12 MHz 12MHz | 12 MHz 0 0 0 1 16 16 16 16 0 0 1 0 20 20 20 20 | 0 0 t I 25 25 25 25 0 1 0 0 33.33 3333, 33.33 33.33 0 1 0 1 40 40 | 40 40 0 1 1 | 0 30 30 44 44 0 I 1 1 Power-down |! Power-down | Power-down | Power-down 1 0 0 0 24 24 24 1 0 0 1 32 32 32 4 0 I 0 40 40 40 l 0 l 1 50 50 50 ) ot 1 0 0 66.66 66.66 66.66 ft 1 0 I 80 80 80 1 I l 0 60 60 88 | t l \ TEST TEST TEST Ordering Information ICS2407-XXXN, ICS2407-XXXM; ICS2409-XXXN, ICS2409-XXXF 1CS2419-XXXN, ICS2419-XXXF; ICS2439-XXXN, ICS2439-XXXF Example: ICS XXXX-XXX M Package Type N=DIP (Plastic) M=SOIC (SOP) F=SSOP Pattern Number (2 or 3 digit number for parts with ROM code patterns) Device Type (consists of 3 or 4 digit numbers) Prefix ICS, AV=Standard Device; GSP=Genlock Device reserves the right PRODUCT PREVIEW documents contain information on products in the formative or desi phase of development. Characteristic data and other specifications are design goals. ICS to change or discontinue these products without notice.