ICS9176-01 Integrated Circuit Systems, Inc. Low Skew Output Buffer General Description Features the ICS9176-01 is designed specifically to support the tight timing requirements of high-performance microprocessors and chip sets. Because the jitter of the device is limited to ±250ps, the ICS9176-01 is ideal for clocking Pentium™ systems. The 10 high drive (40mA), low-skew (±250ps) outputs make the ICS9176-01 a perfect fit for PCI clocking requirements. • • • • • The ICS9176-01 has 10 outputs synchronized in phase and fre-quency to an input clock. The internal phase locked loop (PLL) acts either as a 1X clock multiplier or a 1/2X clock multiplier depending on the state of the input control pins T0 and T1. With metal mask options, any type of ratio between the input clock and output clock can be achieved, including 2X. The PLL maintains the phase and frequency relationship between the input clock and the outputs by externally feeding back FBOUT to FBIN. Any change in the input will be tracked by all 10 outputs. However, the change at the outputs will happen smoothly so no glitches will be present on any driven input. The PLL circuitry matches rising edges of the input clock and the output clock. Since the input to FBIN skew is guaran-teed to ±500ps, the part acts as a “zero delay” buffer. The ICS9176-01 has a total of eleven outputs. Of these, FBOUT is dedicated as the feedback into the PLL and another, Q/2, has an output frequency half that of the remaining nine. These nine outputs can either be running at the same speed as the input, or at half the frequency of the input. With Q/2 as the feedback to FBIN, the nine ‘Q’ outputs will be running at twice the input frequency in the normal divide-by-1 mode. In this case, the output can go to 120 MHz with a 60 MHz input clock. The maximum rise and fall time of an output is 1ns and each is TTL-compatible with a 40mA symmetric drive. • • • • • ICS9176-01-01 is pin compatible with Triquint GA1086 ±500ps skew (max) between input and outputs ±250ps skew (max) between outputs 10 symmetric, TLL-compatible outputs 28-pin PLCC or 28-pin wide SOIC surface mount package High drive, 40mA outputs Power-down option Output frequency range 20 MHz to 120 MHz Input frequency range 20 MHz to 100 MHz Ideal for PCI bus applications Functionality FS1 0 FS0 0 0 1 1 1 0 1 DESCRIPTION Power-down Test Mode (PLL Off CLK=outputs) Normal (PLL On) Divide by 2 Mode Block Diagram The ICS9176-01 is fabricated using CMOS technology which results in much lower power consumption and cost compared with the gallium arsenide based 1086E. The typical operating current for the ICS9176-01 is 60mA versus 115mA for the GA1086E. Pentium is a trademark of Intel Corporation. ICS9176-01-01RevB061297P ICS reserves the right to make changes in the device data identified in this publication without further notice. ICS advises its customers to obtain the latest version of all device data to verify that any information being relied upon by the customer is current and accurate. ICS9176-01 Pin Configuration 28-Pin PLCC 28-Pin SOIC Pin Description PIN NUMBER 1 PIN NAME GND TYPE - DESCRIPTION GROUND. 2 3 4 5 6 7 Q8 Q9 VDD GND NC NC Output Output - Output clock 8 Output clock 9. Power supply (+5V). GROUND. No Connect. No Connect. 8 9 10 11 12 13 VDD CLK FS1 FBIN FS0 VDD Input Input Input Input - 14 15 16 17 18 19 Q/2 GND FBOUT Q1 VDD GND Output Output Output - Half-clock output. GROUND. FEEDBACK OUTPUT to Input FBIN. Output clock 1. Power Supply (+5V). GROUND. 20 21 22 23 24 25 Q2 Q3 VDD Q4 Q5 GND Output Output Output Output - Output clock 2. Output clock 3. Power supply (+5V). Output clock 4. Output clock 5. GROUND. 26 27 28 VDD Q6 Q7 Output Output Power Supply (+5V). Output clock 6. Output clock 7. Power supply (+5V). Input for reference clock. FS1 selects normal operation, power-down, or test mode. FEEDBACK INPUT from output FBOUT. FS0 selects normal operation, power-down, or test mode. Power Supply (+5V). 2 ICS9176-01 Timing Diagrams Timing in Divide by 1 Mode Timing in Divide by 2 Mode Timing in Eliminate by Test Mode Note: In test mode, the VCOs are bypassed. The test clock input is simply buffered, then output. The part is transparent. Damage to the device may occur if an output is shorted or forced to ground or VDD. Timing in Power-down Mode 3 ICS9176-01 Absolute Maximum Ratings VDD referenced to GND . . . . . . . . . . . . . . . . . . . . . . 7V Operating temperature under bias. . . . . . . . . . . . . . . . 0°C to +70°C Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . -65°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 DC Characteristics VDD =+5V±5%, TA=0°C to 70°C unless otherwise stated PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNITS Input Low Voltage VIL VDD=5V - - 0.8 V Input High Voltage VIH VDD=5V 2.0 - - V -5 - 5 µA Input Current Ii VIN=0V, 5V Output Low Voltage VOL @IOL=14mA - 0.25 0.4 V Output Low Current IOL @VOL=0.8V 33 42 - mA Output High Voltage 1 VOH @IOH =-38mA 2.4 - - V Output High Current 1 IOH @VOH =2.0V - -59 -41 mA IDD Unloaded outputs, @ 66.6 Mhz - 55 75 mA T1, T 0=0, 0 - 2.0 10.0 mA Supply Current, Normal Mode Supply Current, Powerdown Mode IDD-PD Note: 1. Guaranteed by design and characterization. Not subject to 100% test. 4 ICS9176-01 AC Characteristics PARAMETER Input Clock Pulse Width 1 SYMBOL CLKW TEST CONDITIONS VDD=4.5V, fCLK=100 MHz MIN 2.5 TYP - MAX 7.5 UNITS ns Output Rise time, 0.8 to 2.0V 1 tr 15pF load - 0.7 1 ns Rise time, 20% to 80% VDD 1 tr 15pF load - 1.5 2 ns Output Fall time, 2.0V to 0.8V 1 tf 15pF load - 0.7 1 ns Fall time, 80% to 20% VDD 1 tf 15pF load - 1.2 2 ns 45 -250 49/51 60 ±100 55 250 % ps ps Output Duty cycle Jitter, 1 sigma 1 Jitter, absolute 1 1 dt Tls Tabs 15pF load, Note 3 20 - 100 MHz fo For outputs >100 MHz, use Q/2 as feedback 20 - 120 MHz FBIN to IN skew 1 tskew1 Note 2, 4. Input rise time < 3ns -500 250 0 ps Skew between any 2 outputs at same frequency 1 tskew2 Note 2, 4. -250 50 250 ps Skew between any 1 out put and Q/2 1 tskew3 Note 2, 4 -3 ±0.1 3 ns Input Frequency Output Frequency (Q outputs) fi Notes: 1. Guaranteed by design and characterization. Not subject ot 100% test. 2. All skew specifications are measured with a 50W transmission line, load terminated with 50W to 1.4V. 3. Duty cycle measured at 1.4V. 4. Skew measured at 1.4V on rising edges. Loading must be equal on outputs. 5 ICS9176-01 Applications FBOUT is normally connected to FBIN to facilitate input to output skew control. However, there is no requirement that the external feedback connection be a direct hardwire from an output pin to the FBIN pin. As long as the signal at FBIN is derived directly from the FBOUT pin and maintains its frequency, additional delays can be accommodated. The clock phase of the outputs (rising edge) will be adjusted so that the phase of FBIN and the input clock will be the same. See Figure 1 for an example. The ICS9176-01 is also ideal for clocking multi-processor sys-tems. The 10 outputs can be used to synchronize the operation of CPU cache and memory banks operating at different speeds. Figure 2 depicts a 2-CPU system in which processors and associated peripherals are operating at 66 MHz. Each of the nine outputs operating at 66 MHz are fully utilized to drive the appropriate CPU, cache and memory control logic. The 33 MHz output is used to synchronize the operation of the slower memory bank to the restart of the system. Figure 1 In Figure 1, the propagation delay through the divide by 2 circuit is eliminated. The internal phase-locked loop will adjust the output clock on the ICS9176-01 to ensure zero phase delay between the FBIN and CLK signals, as a result, the rising edge at the output of the divide by two circuit will be aligned with the rising edge of the 66 MHz input clock. This type of configuration can be used to eliminate propagation delay as long as the signal at FBIN is continuous and is not gated or conditional. Figure 2 6 ICS9176-01 PLCC Package LEAD COUNT FRAME THICKNESS TF ±.0003 PKG. THICKNESS TP ±.004 PKG. WIDTH TOP WT ±.004 PKG. WIDTH BOTTOM WB ±.006 OVERALL PKG. WIDTH WO ±.005 CONTACT WIDTH WO +.010/-.030 28L 0.010 0.152 0.450 0.453 0.490 0.420 Ordering Information ICS9176Q-01 Example: ICS XXXX- M PPP Pattern Number (2 or 3 digit number for parts with ROM code patterns) Package Type Q=PLCC Device Type (consists of 3 or 4 digit numbers) Prefix ICS, AV=Standard Device 7 ICS9176-01 LEAD COUNT 28L DIMENSION L 0.704 SOIC Package Ordering Information ICS9176M-01 Example: ICS XXXX- M PPP Pattern Number (2 or 3 digit number for parts with ROM code patterns) Package Type M=SOIC Device Type (consists of 3 or 4 digit numbers) Prefix ICS, AV=Standard Device 8 ICS reserves the right to make changes in the device data identified in this publication without further notice. ICS advises its customers to obtain the latest version of all device data to verify that any information being relied upon by the customer is current and accurate.