ICS9131 Integrated Circuit Systems, Inc. 32 KhZ Motherboard Frequency Generator General Description Features The ICS9131 offers a tiny footprint solution for generating a selectable CPU clock from a 32.768 kHz crystal. The device allows a variety of microprocessors to be clocked by changing the state of address lines FS0, FS1, and FS2. The ICS9131 is the ideal solution for replacing high speed oscillators and for reducing clock speeds to save power in computers. The device provides smooth, glitch-free frequency transitions so that the CPU can continue to operate during slow down or speed up. The rate of frequency change makes the ICS9131 compatible with all 386DX, 386SX, 486DX, 486DXZ, 486SX and Pentium™ microprocessors. • The ICS9131 is driven from a single 32.768 kHz crystal. The only external components required are the crystal and a 10M ohm resistor. The device generates the 14.318 MHz system clock, eliminating the need for a 14.318 MHz crystal. HighPerformance applications may require high speed clock termination components. • • • • • • • • Single 32.768 kHz crystal generates system clock and selectable CPU clock Generates CPU clocks from 8 MHz to 100 MHz. Operates from 3.3V or 5.0V supply Operates up to 66 MHz at 3.3V Separate VDD for 32 kHz clock enables it to run from battery STOPCLK feature allows for a glitch-free turn-on and Pen-turn-off of the CPU clock to static processors Output enable tristates outputs 16-pin PDIP or SOIC package Frequency selects allow for a smooth transition of the CPUCLK Pin Configuration VDD32 Supply The ICS9131 has a separate power supply for the 32.768 kHz oscillator circuitry. This allows the 32 kHz clock to run from a battery or other source while the main power to the chip is disconnected. The VDD32 supply is guaranteed to operate down to +2.0V, with the clock consuming less than 10µA at +3.3V and the main VDD at 0V. The frequencies and power-down options in the ICS9131 are mask programmable. Customer specific masks can be made and prototypes delivered within 6-8 weeks from receipt of order. ICS also offers standard versions, such as those described in this data sheet. 16-Pin DIP or SOIC Block Diagram Pentium is a trademark of Intel. 9131 Rev B 052897P ICS9131 Pin Descriptions PIN NUMBER 1 PIN NAME 32 kHz TYPE Output DESCRIPTION 2 X2 Output 3 X1 Input 4 5 6 VDD32 VCC VSS 7 AGND 8 9 10 11 12 OE FS2 REFCLK STOPCLK# VSS Input Input Output Input -- OE tristates outputs when low. CPU clock frequency select 2. 14.318 MHz output. Stops CPU clock when low. Ground. 13 14 15 16 VCC CPUCLK FS1 FS0 -Output Input Input Power supply. CPU clock output (see Decoding table). CPU clock frequency select 1. CPU clock frequency select 0. 32.768 kHz output. ---- Connect 32 kHz crystal, this input includes internal load capacitor for crystal. Connect 32 kHz crystal, this input includes internal load capacitor for crystal. Power Supply for 32 kHz oscillator. Power Supply. Ground. -- Analog Ground. Functionality FS2 FS1 FS0 CPUCLK ACTUALS 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 16 25 33.3 40 50 60 66.6 80 16.004 25.059 33.412 40.095 50.119 60.142 66.484 80.190 2 ICS9131 Recommended External Circuit Notes: 1) The external components shown should be placed as close to the device as possible. 2) Pins 5 and 13 should be connected together externally. One decoupling capacitor may suffice for both pins. 3 ICS9131 Absolute Maximum Ratings VDD referenced to GND . . . . . . . . . . . . . . . . . . . . . . 7V Operating temperature under bias. . . . . . . . . . . . . . . . 0°C to +70°C Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +150°C Voltage on I/O pins referenced to GND. . . . . . . . . . . GND -0.5V to VDD +0.5V Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 Watts Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. Electrical Characteristics at 5V Operating VDD = +4.5V to +5.5V; TA =0°C to 70°C unless otherwise stated DC Characteristics PARAMETER Input Low Voltage SYMBOL VIL Input High Voltage Input Low Current Input High Current Pull-up Resistor, Note 1 Output Low Current, Note 1 Output High Current, Note 1 Output Low Voltage VIH IIL IIH Rpu IOL IOH VOL Output High Voltage, Note 1 Supply Current Output Frequency Change over Supply and Temperature, Note 1 Standby Supply Current, Note 2 VOH IDD Fd IDDSTDBY TEST CONDITIONS V IN=0V V IN=VDD V IN=VDD-1V V OUT=0. 8V V OUT=2.0V I OL=10mA I OH=-30mA No load, at 50 MHz With respect to typical frequency Unloaded MIN - TYP - MAX 0.8 UNITS V 2.0 -15.0 -2.0 25 - -6.0 400 45 -53 0.15 2.0 700 -35 0.4 V µA µA k ohms mA mA V 2.4 - 3.7 18 35 V mA - 0.002 0.05 % - 12 25 mA Note 1: Parameter is guaranteed by design and characterization. Not 100% tested in production. Note 2: With the STOPCLK pin low (active). Note 3: Absolute Jitter measured as the shortest and longest period difference to the mean period of the sample set. 4 ICS9131 Electrical Characteristics at 5V Operating VDD = +4.5V to +5.5V; TA =0°C to 70°C unless otherwise stated AC Characteristics PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNITS 12.0 2.0 - 32 0.60 1.6 0.50 0.9 100 38 1.4 3.0 1.2 2.5 MHz kHz ns ns ns ns 45 50 55 % 10,000 samples - 50 150 ps Tjabs 10,000 samples -250 - 250 ps Jitter, 1 sigma from 16-25 MHz, Note 1 Tjis 10,000 samples 60 150 ps Jitter, Absolute from 16-25 MHz, Note 1, 3 Tjabs 10,000 samples -600 - 600 ps Jitter, 1 sigma from 14 to below, Note 1 Tjis 10,000 samples - 1 3 % Jitter, Absolute from 14 to below, Note 1, 3 Tjabs 10,000 samples - 2 5 % Frequency Transition time, Note 1 Power-up time, Note 1 tft tpu 2.0 3.0 5.0 7.5 10.0 15 ms ms Output Frequency, Note 1 Input Frequency, Note 1 Output Rise time, Note 1 Rise time, Note 1 Output Fall time, Note 1 Fall time, Note 1 fo fi tr tr tf tf Clock1 Duty cycle, Note 1 Jitter, 1 sigma from 33-80 MHz, Note 1 dt 15pF load @1.4V Tjis Jitter, Absolute from 33-80 MHz, Notes 1, 3 15pF 15pF 15pF 15pF load, load, load, load, 0.8 to 2.0V 20% to 80% VDD 2.0 to 0.8V 80% to 20% VDD Note 1: Parameter is guaranteed by design and characterization. Not 100% tested in production. Note 2: With the STOPCLK pin low (active). Note 3: Absolute Jitter measured as the shortest and longest period difference to the mean period of the sample set. 5 ICS9131 Electrical Characteristics at 3.3V Operating VDD = +3.3V to +3.7V; TA =0°C to 70°C unless otherwise stated DC Characteristics PARAMETER SYMBOL Input Low Voltage Input High Voltage Input Low Current Input High Current Pull-up Resistor, Note 1 Output Low Current, Note 1 VIL VIH IIL IIH Rpu IOL Output High Current, Note 1 Output Low Voltage, Note 1 Output High Voltage, Note 1 Supply Current Output Frequency Change over Supply and Temperature, Note 1 Standby Supply Current, Note 2 IOH VOL VOH IDD Fd TEST CONDITIONS MIN TYP MAX UNITS 0.7 VDD -7.0 -2.0 15 -2.5 600 24 0.2 V DD 2.0 900 - V V µA µA k ohms mA 6.85 V DD - -13 0.05 V DD 0.94 V DD 13 -8 0.1 V DD 25 mA V V mA - 0.002 0.05 % - 8 15 mA 15pF load, 20% to 80% VDD 15pF load, 80% to 20% VDD 12.0 2.0 - 32 2.2 1.2 100 38 3.5 2.5 MHz kHz ns ns 43 -250 -600 - 50 60 1 53 150 250 150 600 3 % ps ps ps ps % - 2 6.7 8.55 5 14.0 17.0 % ms ms VIN=0V VIN=VDD VIN=VDD-1V VOUT=0.2V VOUT=0.7V IOL=60mA IOH=-4.0mA No load, at 50 MHz With respect to typical frequency IDDSTDBY No load fo fi tr tf Clock1 AC Characteristics Output Frequency, Note 1 Input Frequency, Note 1 Rise time, Note 1 Fall time, Note 1 Duty cycle, Note 1 Jitter, 1 sigma , Note 1 Jitter, Absolute, Note 1, 3 Jitter, 1 sigma from 16-25 MHz Jitter, Absolute from 16-25 MHz Jitter, 1 sigma from 14 to below dt Tjis Tjabs Tjis Tjabs Tjis 15pF load @50% V DD 10,000 samples 10,000 samples 10,000 samples 10,000 samples 10,000 samples Jitter, Absolute from 14 to below Frequency Transition time, Note 1 Power-up time, Note 1 Tjabs tft tpu 10,000 samples - Note 1: Parameter is guaranteed by design and characterization. Not 100% tested in production. Note 2: With the STOPCLK pin low (active). Note 3: Absolute Jitter measured as the shortest and longest period difference to the mean period of the sample set. 6 ICS9131 Stop Clock Feature The ICS9131 incorporates a unique stop clock feature compat-ible with static logic processors. When the stop clock pin goes low, the CPUCLK will go low after the next occuring falling edge. When STOPCLK again goes high, CPUCLK resumes on the next rising edge of the internal clock. This feature enables fast, glitch-free starts and stops of the CPUCLK and is useful in Energy Star motherboard applications. 32 kHz Supply Current ADVANCE INFORMATION documents contain information on new products in the sampling or preproduction phase of development. Characteristic data and other specifications are subject to change without notice. 7 ICS9131 16-Pin DIP Package 16-Pin SOIC Package Ordering Information ICS9131-01CN16 or ICS9131-01CS16 Example: ICS XXXX M X#W Lead Count & Package Width Lead Count=1, 2 or 3 digits W=.3” SOIC or .6” DIP; None=Standard Width Package Type N=DIP (Plastic) S=SOIC Device Type (consists of 3 or 4 digit numbers) Prefix ICS, AV=Standard Device 8