PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Features Description • Eight Pairs of Differential Clocks PI6C20800 is a high-speed, low-noise differential clock buffer designed to be a companion to PI6C410B. The device distributes the differential SRC clock from PI6C410B to eight differential pairs of clock outputs either with or without PLL. The input SRC clock can be divided by 2 when SRC_DIV# is LOW. The clock outputs are controlled by input selection of SRC_STOP#, PWRDWN# and SMBus, SCLK and SDA. When input of either SRC_STOP# or PWRDWN# is LOW, the output clocks are Tristated. When PWRDWN# is LOW, the SDA and SCLK inputs must be Tristated. • Low skew < 50ps • Low Cycle-to-cycle jitter < 50ps • Output Enable for all outputs • Outputs Tristate control via SMBus • Power Management Control • Programmable PLL Bandwidth • PLL or Fanout operation • 3.3V Operation • Packaging (Pb-Free & Green): — 48-Pin SSOP (V) — 48-Pin TSSOP (A) Pin Configuration Block Diagram OE_INV OE [0:7] SRC_STOP# PWRDWN# SCLK SDA Output Control OUT0 OUT0# OUT0 OUT1# SMBus Controller OUT2 OUT2# PLL/BYPASS# OUT3 OUT3# OUT4 OUT4# SRC_DIV# SRC SRC# PLL_BW# SRC_DIV# VDD VSS SRC SRC# OE_0 OE_3 OUT0 OUT0# VSS VDD OUT1 OUT1# OE_1 OE_2 OUT2 OUT2# VSS VDD OUT3 OUT3# PLL/BYPASS# SCLK SDA OUT5 OUT5# PLL DIV OUT6 OUT6# OUT7 OUT7# LOCK 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 VDD_A VSS_A IREF LOCK OE_7 OE_4 OUT7 OUT7# OE_INV VDD OUT6 OUT6# OE_6 OE_5 OUT5 OUT5# VSS VDD OUT4 OUT4# PLL_BW# SRC_STOP PWRDWN# VSS PS8746C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Pin Descriptions Type Pin # SRC_DIV# Input 1 3.3V LVTTL input for selecting input frequency divide by 2, active LOW. SRC & SRC# Input 4, 5 0.7V Differential SRC input from PI6C410 clock synthesizer OE [0:7] Input 6, 7, 14, 15, 35, 36, 43, 44 Pin Name OE_INV Descriptions 3.3V LVTTL input for enabling outputs, active HIGH. 3.3V LVTTL input for inverting the OE, SRC_STOP# and PWRDWN# pins. When 0 = same stage When 1 = OE[0:7], SRC_STOP#, PWRDWN# inverted. Input 40 Output 8, 9, 12, 13, 16 17, 20, 21, 29, 30, 33, 34, 37, 38, 41, 42 PLL/BYPASS# Input 22 3.3V LVTTL input for selecting fan-out of PLL operation. SCLK Input 23 SMBus compatible SCLOCK input SDA I/O 24 SMBus compatible SDATA IREF Input 46 External resistor connection to set the differential output current SRC_STOP# Input 27 3.3V LVTTL input for SRC stop, active LOW PLL_BW# Input 28 3.3V LVTTL input for selecting the PLL bandwidth PWRDWN# Input 26 3.3V LVTTL input for Power Down operation, active LOW LOCK Output 45 3.3V LVTTL output, transition high when PLL lock is achieved (Latched output) VDD Power 2, 11, 19, 31, 39 3.3V Power Supply for Outputs VSS Ground 3, 10, 18, 25, 32 Ground for Outputs VSS_A Ground 47 Ground for PLL VDD_A Power 48 3.3V Power Supply for PLL OUT[0:7] & OUT[0:7]# 0.7V Differential outputs Serial Data Interface (SMBus) PI6C20800 is a slave only SMBus device that supports indexed block read and indexed block write protocol using a single 7-bit address and read/write bit as shown below. Address assignment A6 A5 A4 A3 A2 A1 A0 R/W 1 1 0 1 1 1 0 0/1 Data Protocol(1) 1 bit 7 bits 1 1 8 bits 1 8 bits 1 8 bits 1 8 bits 1 1 bit Start bit Slave Addr R/W Ack Register offset Ack Byte Count =N Ack Data Byte 0 Ack Data Byte N -1 Ack Stop bit Note: 1. Register offset for indicating the starting register for indexed block write and indexed block read. Byte Count in write mode cannot be 0. 2 PS8746C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Data Byte 0: Control Register Bit Descriptions Type Power Up Condition Output(s) Affected Pin 0 SRC_DIV# 0 = Divide by 2 1 = Normal RW 1 = x1 OUT[0:7], OUT[0:7]# NA 1 PLL/BYPASS# 0 = Fanout 1 = PLL RW 1 = PLL OUT[0:7], OUT[0:7]# NA 2 PLL Bandwidth 0 = HIGH Bandwidth, 1 = LOW Bandwidth RW 1 = Low OUT[0:7], OUT[0:7]# NA 3 TBD NA 4 TBD NA 5 TBD NA 6 SRC_STOP# 0 = Driven when stopped 1 = Tristate RW 0 = Driven when stopped OUT[0:7], OUT[0:7]# 7 PWRDWN# 0 = Driven when stopped 1 = Tristate RW 0 = Driven when stopped OUT[0:7], OUT[0:7]# NA Type Power Up Condition Output(s) Affected Pin 0 RW 1 = Enabled OUT0, OUT0# NA 1 RW 1 = Enabled OUT1, OUT1# NA RW 1 = Enabled OUT2, OUT2# NA RW 1 = Enabled OUT3, OUT3# NA RW 1 = Enabled OUT4, OUT4# NA RW 1 = Enabled OUT5, OUT5# NA 6 RW 1 = Enabled OUT6, OUT6# NA 7 RW 1 = Enabled OUT7, OUT7# NA Data Byte 1: Control Register Bit 2 3 4 5 Descriptions OUTPUTS enable 1 = Enabled 0 = Disabled 3 PS8746C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Data Byte 2: Control Register Bit Type Power Up Condition Output(s) Affected Pin 0 RW 0 = Free running OUT0, OUT0# NA 1 RW 0 = Free running OUT1, OUT1# NA RW 0 = Free running OUT2, OUT2# NA RW 0 = Free running OUT3, OUT3# NA RW 0 = Free running OUT4, OUT4# NA RW 0 = Free running OUT5, OUT5# NA 6 RW 0 = Free running OUT6, OUT6# NA 7 RW 0 = Free running OUT7, OUT7# NA Type Power Up Condition Output(s) Affected Pin Type Power Up Condition Output(s) Affected Pin 0 R 0 NA NA 1 R 0 NA NA 2 R 0 NA NA R 0 NA NA R 0 NA NA 5 R 1 NA NA 6 R 0 NA NA 7 R 0 NA NA 2 3 4 5 Descriptions Allow control of OUTPUTS with assertion of SRC_STOP# 0 = Free running 1 = Stopped with SRC_Stop# Data Byte 3: Control Register Bit Descriptions 0 RW 1 RW 2 RW 3 4 TBD RW RW 5 RW 6 RW 7 RW Data Byte 4: Pericom ID Register Bit 3 4 Descriptions Pericom ID 4 PS8746C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Functionality PWRDWN# OUT OUT# SRC_Stop# OUT OUT# 1 Normal Normal 1 Normal Normal 0 IREF × 2 or Float LOW 0 IREF × 6 or Float LOW Power Down (PWRDWN# assertion) PWRDWN# OUT OUT# Figure 1. Power down sequence Power Down (PWRDWN# De-assertion) Tstable <1ms PWRDWN# OUT OUT# Tdrive_PwrDwn# <300us, >200mV Figure 2. Power down de-assert sequence 5 PS8746C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Current-mode output buffer characteristics of OUT[0:7], OUT[0:7]# VDD (3.3V ± 5%) Slope ~ 1/Rs RO IOUT ROS Iout 0V VOUT = 0.85V max 0.85V Figure 9. Simplified diagram of current-mode output buffer Differential Clock Buffer characteristics Symbol Minimum Maximum RO 3000Ω N/A ROS unspecified unspecified VOUT N/A 850mV Current Accuracy Symbol Conditions Configuration IOUT VDD = 3.30 ±5% RREF = 475Ω 1% IREF = 2.32mA Load Nominal test load for given configuration Min. Max. -12% INOMINAL +12% INOMINAL Note: 1. INOMINAL refers to the expected current based on the configuration of the device. Differential Clock Output Current Board Target Trace/Term Z Reference R, Iref = VDD/(3xRr) Output Current VOH @ Z 100Ω (100Ω differential ≈ 15% coupling ratio) RREF = 475Ω 1%, IREF = 2.32mA IOH = 6 x IREF 0.7V @ 50 6 PS8746C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Absolute Maximum Ratings(1) (Over operating free-air temperature range) Symbol VDD_A Parameters Min. Max. 3.3V Core Supply Voltage -0.5 4.6 VDD 3.3V I/O Supply Voltage -0.5 4.6 VIH Input HIGH Voltage VIL Input LOW Voltage -0.5 Ts Storage Temperature -65 VESD 4.6 ESD Protection 150 2000 Units V °C V Note: 1. Stress beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. DC Electrical Characteristics (VDD = 3.3±5%, VDD_A = 3.3±5%) Symbol Parameters VDD_A Condition Min. Max. 3.3V Core Supply Voltage 3.135 3.465 VDD 3.3V I/O Supply Voltage 3.135 3.465 VIH 3.3V Input HIGH Voltage 2.0 VDD + 0.3 VIL 3.3V Input LOW Voltage VSS – 0.3 0.8 IIK Input Leakage Current 0 < VIN < VDD -5 +5 VOH 3.3V Output HIGH Voltage IOH = -1mA 2.4 VOL 3.3V Output LOW Voltage IOL = 1mA IOH Output HIGH Current IOH = 6 x IREF, IREF = 2.32mA CIN Logic Input Pin Capacitance COUT Output Pin Capacitance 6 LPIN Pin Inductance 7 IDD Power Supply Current VDD = 3.465V, FCPU = 200MHz 250 ISS Power Down Current Driven outputs 60 ISS Power Down Current Tristate outputs 12 TA Ambient Temperature VDD 0.4 12.2 15.6 1.5 0 7 5 70 PS8746C Units V μA V mA pF nH mA °C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets AC Switching Characteristics(1,2,3) (VDD = 3.3±5%, VDD_A = 3.3±5%) Symbol Trise / Tfall ΔTrise / ΔTfall Parameters Min Max. Rise and Fall Time (measured between 0.175V to 0.525V) 175 700 Units Notes 2 ps Rise and Fall Time Variation 125 Tskew Output-to-Output Skew 50 VHIGH Voltage HIGH VOVS Max. Voltage VUDS Min. Voltage -300 VLOW Voltage LOW -150 +150 Vcross Absolute crossing poing voltages 250 550 2 140 2 ΔVcross TDC Tjcyc-cyc 660 ps 850 2 3 2 1150 Total Variation of Vcross over all edges Duty Cycle 45 Jitter, Cycle-to-cycle (PLL Mode, Measurement for differential waveform) mV 55 % 50 ps 2 3 Jitter, Cycle-to-cycle (BYPASS mode as additive jitter) Notes: 1. Test configuration is RS = 33.2Ω, Rp = 49.9Ω, and 2pF. 2. Measurement taken from Single Ended waveform. 3. Measurement taken from Differential waveform. Configuration Test Load Board Termination Rs 33Ω 5% OUT TLA PI6C20800 Rs 33Ω 5% OUT# TLB 475Ω 1% Rp 49.9Ω 1% Rp 49.9Ω 1% 8 2pF 5% 2pF 5% PS8746C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Packaging Mechanical: 48-Pin SSOP (V) 48 .291 .299 7.39 7.59 .395 .420 10.03 10.67 Gauge Plane .010 0.25 .02 0.51 .04 1.01 1 .620 .630 15.75 16.00 .015 0.381 x 45˚ .025 0.635 .008 0.20 Nom. .110 2.79 Max .008 0.20 .0135 0.34 .025 BSC 0.635 .008 0.20 .016 0.40 0-8˚ X.XX DENOTES DIMENSIONS X.XX IN MILLIMETERS Packaging Mechanical: 48-Pin TSSOP (A) 48 .236 .244 1 6.0 6.2 .488 12.4 .496 12.6 .047 1.20 Max SEATING PLANE .004 0.09 .008 0.20 X.XX X.XX DENOTES DIMENSIONS IN MILLIMETERS .0197 BSC 0.50 .002 .006 0.05 0.15 .007 .010 0.17 0.27 9 0.45 .018 0.75 .030 .319 BSC 8.1 PS8746C 02/01/06 PI6C20800 1:8 Clock Driver for Intel PCI Express Chipsets Ordering Information(1,2) Ordering Code Package Code Package Description PI6C20800VE VE 48-pin, 300-mil wide, SSOP, Pb-Free and Green PI6C20800AE AE 48-pin, 240-mil wide, TSSOP, Pb-Free and Green Notes: 1. Thermal characteristics can be found on the company web site at www.pericom.com/packaging/ 2. E = Pb-free and Green Pericom Semiconductor Corporation • 1-800-435-2336 • www.pericom.com 10 PS8746C 02/01/06