ICS9179BF-01

ICS9179B-01 Integrated Circuit Systems, Inc. Low Skew Buffers General Description Features The ICS9179B-01 generates SDRAM clock buffers required for high speed RISC or CISC microprocessor systems such as Intel PentiumPro or Pentium II. An output enable is provided for testability. • The device is a buffer with low output to output skew. This is a Fanout buffer device, not using an internal PLL. This buffer can also be a feedback to an external PLL stage for phase synchronization to a master clock. • The individual clock outputs are addressable through I2C to be enabled, or stopped in a low state for reduced EMI when the lines are not needed. • Block Diagram • • • • • • High speed, low noise non-inverting (0:17) buffer for SDRAM clock buffer applications. Supports up to four SDRAM DIMMS Synchronous clocks skew matched to 250 ps window on SDRAM. I2C Serial Configuration interface to allow individual clocks to be stopped. Multiple VDD, VSS pins for noise reduction Tri-state pin for testing Custom configurations available 3.0V – 3.7V supply range 48-pin SSOP package Pin Configuration 48-Pin SSOP 0256E—12/15/08 PentiumPro is a trademark of Intel Corporation I2C is a trademark of Philips Corporation ICS9179B-01 Pin Descriptions PIN NUMBER PIN NAME TYPE DESCRIPTION 4, 5, 8, 9 SDRAM (0:3) OUT SDRAM Byte 0 clock outputs1 13, 14, 17, 18 SDRAM (4:7) OUT SDRAM Byte 1 clock outputs1 31, 32, 35, 36 SDRAM (8:11) OUT SDRAM Byte 2 clock outputs1 40, 41, 44, 45 SDRAM (12:15) OUT SDRAM Byte 3 clock outputs1 21, 28 SDRAM (16:17) OUT SDRAM clock outputs useable for feedback.1 11 BUF_IN IN Input for buffers Tri-states all outputs when held LOW. Has internal 38 OE IN pull-up. 2 24 SDATA I/O Data pin for I2C circuitry3 25 SCLK I/O Clock pin for I2C circuitry3 3, 7, 12, 16, 20, 29, 33, 37, VDD PWR 3.3V Power supply for SDRAM buffer 42, 46 6, 10, 15, 19, 22, 27, 30, 34, GND PWR Ground for SDRAM buffer 39, 43 23 VDDS PWR 3.3V Power supply for I2C circuitry 26 GNDS PWR Ground for I2C circuitry 1, 2, 47, 48 N/C Pins are not internally connected Notes: 1. At power up all eighteen SDRAM outputs are enabled and active. 2. OE has a 100K Ohm internal pull-up resistor to keep all outputs active. 3. The SDATA and SCLK inputs both also have internal pull-up resistors with values above 100K Ohms as well for complete platform flexibility. Power Groups VDD = Power supply for SDRAM buffer VDDS = Power supply for I2C circuitry Ground Groups GND = Ground for SDRAM buffer GNDS = Ground for I2C circuitry 2 ICS9179B-01 Technical Pin Function Descriptions VDD This is the power supply to the internal core logic of the device as well as the clock output buffers for SDRAM(0:17). This pin operates at 3.3V volts. Clocks from the listed buffers that it supplies will have a voltage swing from Ground to this level. For the actual guaranteed high and low voltage levels for the Clocks, please consult the DC parameter table in this data sheet. GND This is the power supply ground (common or negative) return pin for the internal core logic and all the output buffers. SDRAM(0:17) These Output Clocks are use to drive Dynamic RAM’s and are low skew copies of the CPU Clocks. The voltage swing of the SDRAM’s output is controlled by the supply voltage that is applied to VDD of the device, operates at 3.3 volts. I2C The SDATA and SCLOCK Inputs are use to program the device. The clock generator is a slave-receiver device in the I2C protocol. It will allow read-back of the registers. See configuration map for register functions. The I2C specification in Philips I2C Peripherals Data Handbook (1996) should be followed. BUF_IN Input for Fanout buffers (SDRAM 0:17). OE OE tristates all outputs when held low. VDDS This is the power supply to I2C circuitry. GNDS This is the ground to I2C circuitry. 3 ICS9179B-01 General I2C serial interface information A. For the clock generator to be addressed by an I2C controller, the following address must be sent as a start sequence, with an acknowledge bit between each byte. Then Byte 0, 1, 2, etc in sequence until STOP. B. The clock generator is a slave/receiver I2C component. It can "read back "(in Philips I2C protocol) the data stored in the latches for verification. (set R/W# to 1 above). There is no BYTE count supported, so it does not meet the Intel SMB PIIX4 protocol. Byte 0, 1, 2, etc in sequence until STOP. C. The data transfer rate supported by this clock generator is 100K bits/sec (standard mode) D. The input is operating at 3.3V logic levels. E. The data byte format is 8 bit bytes. F. To simplify the clock generator I2C interface, the protocol is set to use only block writes from the controller. The bytes must be accessed in sequential order from lowest to highest byte with the ability to stop after any complete byte has been transferred. The Command code and Byte count shown above must be sent, but the data is ignored for those two bytes. The data is loaded until a Stop sequence is issued. G. In the power down mode (PWR_DWN# Low), the SDATA and SCLK pins are tristated and the internal data latches maintain all prior programming information. H. At power-on, all registers are set to a default condition. Bytes 0 through 2 default to a 1 (Enabled output state). Serial Configuration Command Bitmaps Byte 0: SDRAM Clock Register Notes: 1 = Enabled; 0 = Disabled, outputs held low Note: PWD = Power-Up Default 4 ICS9179B-01 Functionality Byte 1: SDRAM Clock Register Byte 2: PCICLK Clock Register BIT PWDPWD DESCRIPTION BIT PIN# PIN# DESCRIPTION SDRAM15 45 1 (Act/Inact) SDRAM17 Bit 7 28 1 (Act/Inact) SDRAM14 Bit 6 44 1 (Act/Inact) SDRAM16 SDRAM13 Bit 1 1(Act/Inact) Bit 5 6 41 21 Notes: 1 (Act/Inact) = Enabled; 0 = Disabled, SDRAM12 Bit 4 5 40 - 1 (Act/Inact) Bit 1 Reserved Note: PWD = Power-Up Default SDRAM11 Bit 1 Reserved Bit 3 4 36 - 1 (Act/Inact)) Bit 1 Reserved SDRAM10 2 2 3 35 Bit 1 (Act/Inact) Bit 2 1 Reserved SDRAM9 Bit 1 32 1 (Act/Inact) Bit 1 1 Reserved SDRAM8 Bit 0 0 31 - 1 (Act/Inact)) Bit 1 Reserved OE# Bit 7 0 Max 3.3V supply consumption SDRAM (0:3)Max SDRAM (4:7)loadsSDRAM (8:11) discrete cap Condition Hi-Z VDD = 3.465V All static inputs = VDD GND Hi-Zoutputs Hi-Z heldorlow SDRAM (12:15) SDRAM (16:17) Hi-Z Hi-Z 1 X BUF_IN 1 X BUF_IN Notes: 1 = Enabled; 0 = Disabled, outputs held low No Clock Mode 1 - VDD1 1 X BUF_IN 1 X BUF_IN 1 X BUF_IN (BUF_IN or 3mA GND) I C Circuitry Active Active 66MHz 115mA Power Management (BUF_IN =ICS9179B-01 66.66MHz) The values below are estimates of target specifications. Active 100MHz 180mA (BUF_IN = 100.00MHz) 5 ICS9179B-01 Absolute Maximum Ratings Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . 7.0 V Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . GND –0.5 V to VDD +0.5 V Ambient Operating Temperature . . . . . . . . . . 0°C to +70°C Storage Temperature . . . . . . . . . . . . . . . . . . . –65°C to +150°C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are stress specifications only and functional operation of the device at these or any other conditions above those listed in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. 6 ICS9179B-01 Electrical Characteristics - SDRAM TA = 0 - 70C; VDD = VDDL = 3.3 V +/-5%; CL = 20 - 30 pF (unless otherwise stated) PARAMETER Output Impedance Output Impedance Output High Voltage Output Low Voltage Output High Current Output Low Current Rise Time1 SYMBOL RDSP RDSN VOH VOL I OH I OL CONDITIONS VO = VDD*(0.5) VO = VDD*(0.5) I OH = -36 mA I OL = 23 mA VOH = 2.0 V VOL = 0.8 V MIN 10 10 2.4 TYP 40 3 0.27 -115 57 MAX UNITS 24 W 24 W V 0.4 V -54 mA mA Tr VOL = 0.4 V, VOH = 2.4 V 0.5 0.95 1.33 ns Fall Time1 Tf VOH = 2.4 V, VOL = 0.4 V 0.5 0.95 1.33 ns Duty Cycle1 Dt VT = 1.5 V 45 51 55 % Tsk TPROP VT = 1.5 V VT = 1.5 V 1 110 5 250 6 ps ns TPROPEN TPROPDIS VT = 1.5 V VT = 1.5 V 1 1 8 8 ns ns 1 Skew 1 Propagation 1 Guarenteed by design, not 100% tested in production. 7 ICS9179B-01 General Layout Precautions: 1) Use a ground plane on the top layer of the PCB in all areas not used by traces. 2) Make all power traces and vias as wide as possible to lower inductance. Notes: 1 All clock outputs should have series terminating resistor. Not shown in all places to improve readibility of diagram 2 Optional EMI capacitor should be used on all CPU, SDRAM, and PCI outputs. Capacitor Values: All unmarked capacitors are 0.01µF ceramic 8 ICS9179B-01 SSOP Package SYMBOL A A1 A2 B C D E e H h L N µ X COMMON DIMENSIONS MIN. NOM. MAX. .095 .101 .110 .008 .012 .016 .088 .090 .092 .008 .010 .0135 .005 .010 See Variations .292 .296 .299 0.025 BSC .400 .406 .410 .010 .013 .016 .024 .032 .040 See Variations 0° 5° 8° .085 .093 .100 VARIATIONS AC MIN. .620 D NOM. .625 Ordering Information 9179BF-01LF Example: XXXX F - PPP LF denotes Pb-free configuration, RoHS compliant Pattern Number (2 or 3 digit number for parts with ROM code patterns) Package Type F=SSOP Device Type 9 N MAX. .630 48 ICS9179B-01 10