DATASHEET IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Recommended Applications Features/Benefits One output synthesizer for PCIe Gen1/2 • 16-pin QFN package; very small board footprint • Spread-spectrum capable; reduces EMI • Outputs can be terminated to LVDS; can drive a wider General Description variety of devices The IDT5V41064 is a PCIe Gen2 compliant spread spectrum capable clock generator. The device has 1 differential HCSL output and can be used in communication or embedded systems to subtantially reduce electro-magnetic interference (EMI). Spread spectrum can be enabled via a select pin. • Spread enable via pin selection; no software required to configure device • Industrial temperature range available; supports demanding embedded applications • For PCIe Gen3 applications, see the 5V41234 Output Features Key Specifications • 1 - 0.7V current mode differential HCSL output pairs • Cycle-to-cycle jitter < 100 ps • PCIe Gen2 phase jitter < 3.0ps RMS Block Diagram VDD SS1 Control Logic CLK Phase Lock Loop X1 25 MHz crystal /clock X2 Clock Buffer/ Crystal Oscillator Crystal Tuning Capacitors GND IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER CLK 1 RR (IREF) IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER GND NC VDD Spread Spectrum Select Table NC NC Pin Assignment 13 1 CLK X1 CLK X2 GND NC 0 -0.5% down 1 No spread NC IREF SS1 GND Spread% VDDA 9 5 SS1 16-pin QFN Pin Descriptions Pin Number Pin Name Pin Type Pin Description 1 GND Power 2 X1 XI Crystal or clock input. Connect to 25 MHz crystal or single-ended clock. 3 X2 XO Crystal connection. Connect to parallel mode crystal. Leave floating if X1 is driven by single-ended clock. 4 NC – 5 GND Power Connect to ground. 6 SS1 Input Spread Select 1. See table above. Internal pull-up resistor. 7 IREF Output 8 NC – 9 VDDA Power Connect to 3.3V and filter as analog supply. 10 GND Power Connect to ground. 11 CLK Output HCSL complementary output clock. 12 CLK Output HCSL true output clock. 13 NC – No connect. 14 NC – No connect. 15 VDD Power 16 NC – Connect to ground. No connect. 475Ω precision resistor must be attached to this pin, which is connected to internal current source. No connect. Connect to 3.3 V for OSC and digital circuits. No connect. IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER 2 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Applications Information Output Structures External Components A minimum number of external components are required for proper operation. IREF =2.3 mA 6*IREF Decoupling Capacitors Decoupling capacitors of 0.01 μF should be connected between VDD and the ground plane (pin 4) as close to the VDD pin as possible. Do not share ground vias between components. Route power from power source through the capacitor pad and then into IDT pin. Crystal A 25 MHz fundamental mode parallel resonant crystal with CL = 16 pF should be used. This crystal must have less than 300 ppm of error across temperature in order for the IDT5V41064 to meet PCI Express specifications. R R 475 Ω See Layout Guidelines Crystal Capacitors General PCB Layout Recommendations Crystal capacitors are connected from pins X1 to ground and X2 to ground to optimize the accuracy of the output frequency. For optimum device performance and lowest output phase noise, the following guidelines should be observed. 1. Each 0.01µF decoupling capacitor should be mounted on the component side of the board as close to the VDD pin as possible. CL= Crystal’s load capacitance in pF Crystal Capacitors (pF) = (CL- 8) * 2 2. No vias should be used between decoupling capacitor and VDD pin. For example, for a crystal with a 16 pF load cap, each external crystal cap would be 16 pF. (16-8)*2=16. 3. The PCB trace to VDD pin should be kept as short as possible, as should the PCB trace to the ground via. Distance of the ferrite bead and bulk decoupling from the device is less critical. Current Source (Iref) Reference Resistor - RR If board target trace impedance (Z) is 50Ω, then RR = 475Ω (1%), providing IREF of 2.32 mA. The output current (IOH) is equal to 6*IREF. 4. An optimum layout is one with all components on the same side of the board, minimizing vias through other signal layers (any ferrite beads and bulk decoupling capacitors can be mounted on the back). Other signal traces should be routed away from the IDT5V41064.This includes signal traces just underneath the device, or on layers adjacent to the ground plane layer used by the device. Output Termination The PCI-Express differential clock outputs of the IDT5V41064 are open source drivers and require an external series resistor and a resistor to ground. These resistor values and their allowable locations are shown in detail in the PCI-Express Layout Guidelines section. The IDT5V41064 can also be terminated to LVDS compatible voltage levels. See Layout Guidelines section. IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER 3 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Layout Guidelines for PCI Express PCIe Reference Clock Common Recommendations for Differential Routing Dimension or Value L1 length, route as non-coupled 50ohm trace 0.5 max L2 length, route as non-coupled 50ohm trace 0.2 max L3 length, route as non-coupled 50ohm trace 0.2 max Rs 33 Rt 49.9 Unit inch inch inch ohm ohm Figure 1 1 1 1 1 Down Device Differential Routing L4 length, route as coupled microstrip 100ohm differential trace L4 length, route as coupled stripline 100ohm differential trace 2 min to 16 max 1.8 min to 14.4 max inch inch 1 1 Differential Routing to PCI Express Connector L4 length, route as coupled microstrip 100ohm differential trace L4 length, route as coupled stripline 100ohm differential trace 0.25 to 14 max 0.225 min to 12.6 max inch inch 2 2 Figure 1: Down Device Routing L2 L1 Rs L4 L4' L2' L1' Rs Rt HCSL Output Buffer Rt L3' PCI Express Down Device REF_CLK Input L3 Figure 2: PCI Express Connector Routing L2 L1 Rs L4 L4' L2' L1' Rs Rt HCSL Output Buffer Rt L3' IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER 4 PCI Express Add-in Board REF_CLK Input L3 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Layout Guidelines for LVDS and Other Applications Alternative Termination for LVDS and other Common Differential Signals (figure 3) Vdiff Vp-p Vcm R1 R2 R3 R4 Note 0.45v 0.22v 1.08 33 150 100 100 0.58 0.28 0.6 33 78.7 137 100 0.80 0.40 0.6 33 78.7 none 100 ICS874003i-02 input compatible 0.60 0.3 1.2 33 174 140 100 Standard LVDS R1a = R1b = R1 R2a = R2b = R2 Figure 3 L2 L1 R3 R1a R4 L4 L4' L2' L1' R1b R2a HCSL Output Buffer R2b L3' Down Device REF_CLK Input L3 Cable Connected AC Coupled Application (figure 4) Component Value Note R5a, R5b 8.2K 5% R6a, R6b 1K 5% Cc 0.1 µF Vcm 0.350 volts Figure 4 3.3 Volts R5a R5b R6a R6b Cc L4 L4' Cc IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER 5 PCIe Device REF_CLK Input IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Typical PCI-Express (HCSL) Waveform 700 mV 0 tOR 500 ps 500 ps 0.525 V 0.175 V tOF 0.525 V 0.175 V Typical LVDS Waveform 1325 mV 1000 mV tOR 500 ps 500 ps 1250 mV 1150 mV IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER tOF 1250 mV 1150 mV 6 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Absolute Maximum Ratings Stresses above the ratings listed below can cause permanent damage to the IDT5V41064. These ratings are stress ratings only. 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 can affect product reliability. Electrical parameters are guaranteed only over the recommended operating temperature range. Item Rating Supply Voltage, VDD, VDDA 5.5 V All Inputs and Outputs -0.5 V to VDD+0.5 V Ambient Operating Temperature (commercial) 0 to +70° C Ambient Operating Temperature (industrial) -40 to +85° C Storage Temperature -65 to +150° C Junction Temperature 125° C Soldering Temperature 260° C ESD Protection (Input) 2000 V min. (HBM) DC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature -40 to +85° C Parameter Symbol Supply Voltage Input High Voltage1 Input Low Voltage 1 2 Conditions Min. Typ. Max. Units V 3.135 3.465 VIH 2.2 VDD +0.3 V VIL VSS-0.3 0.8 V Input Leakage Current IIL 0 < Vin < VDD 5 μA Operating Supply Current IDD 2 pF load 70 mA Input Capacitance CIN Input pin capacitance 7 pF Output pin capacitance 6 pF 5 nH Output Capacitance COUT Pin Inductance LPIN Output Resistance Rout CLK outputs Pull-up Resistor RPUP SS1 -5 3.0 kΩ 100 kΩ 1 Single edge is monotonic when transitioning through region. 2 Inputs with pull-ups/-downs are not included. IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER 7 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER AC Electrical Characteristics - CLK/CLK Unless stated otherwise, VDD=3.3 V ±5%, Ambient Temperature -40 to +85° C Parameter Symbol Conditions Min. Typ. Input Frequency Max. Units 25 Output Frequency MHz 100 MHz Output High Voltage1,2 VOH 660 700 850 mV Voltage1,2 VOL -150 0 27 mV 250 350 550 mV Output Low Crossing Point Voltage1,2 Absolute Crossing Point Voltage1,2,4 Variation over all edges Jitter, Cycle-to-Cycle1,3 Rise Fall Time1,2 Time1,2 Rise/Fall Time 40 140 mV 25 100 ps tOR From 0.175 V to 0.525 V 175 332 700 ps tOF From 0.525 V to 0.175 V 175 344 700 ps 75 125 ps 45 51 55 % 3.0 ms Variation1,2 Duty Cycle1,3 Stabilization Time tSTABLE From power-up VDD=3.3 V 1.2 Spread Change Time tSPREAD Settling period after spread change 3.0 1 Test ms setup is RS=33 ohms RP=50 ohms with 2 pF, RR = 475Ω (1%). 2 Measurement taken from a single-ended waveform. 3 Measurement taken from a differential waveform. 4 Measured at the crossing point where instantaneous voltages of both CLK and CLK are equal. Electrical Characteristics - Differential Phase Jitter Parameter Jitter, Phase Symbol Conditions Min Typ Max Units Notes tjphasePLL PCIe Gen1 30 86 ps (p-p) 1,2,3 tjphaseLO PCIe Gen2, 10 kHz < f < 1.5 MHz 1.2 3 ps (RMS) 1,2,3 PCIe Gen2, 1.5 MHz < f < Nyquist (50 MHz) 1.9 3.1 ps (RMS) 1,2,3 tjphaseHIGH Note 1. Guaranteed by design and characterization, not 100% tested in production. Note 2. See http://www.pcisig.com for complete specs. Note 3: Applies to 100MHz, spread off and 0.5% down spread only. Thermal Characteristics Parameter Thermal Resistance Junction to Ambient Thermal Resistance Junction to Case IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Symbol Conditions Min. Typ. Max. Units θ JA Still air 63.2 ° C/W θ JA 1 m/s air flow 55.9 ° C/W θ JA 2 m/s air flow 53.1 ° C/W θ JA 3 m/s air flow 51.4 ° C/W 65.8 ° C/W θ JC 8 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Marking Diagrams XXX YWW$ 064G XXX YWW$ 064GI Notes: 1. Line 1: ‘XXX’ is the lot traceability (last numeric character of the assembly lot number). 2. Line 2: ‘YYW’ – Date code; $ – Assembly location. 3. Line 3: truncated IDT part number. 4. “G” designates RoHS compliant package. 5. “I” within the part number indicates industrial temperature range. IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER 9 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Package Outline and Package Dimensions (16-pin QFN) Package dimensions are kept current with JEDEC Publication No. 95 Seating Plane A1 Index Area N 1 2 (Ref) ND & NE Even (ND-1)x e (Ref) L A3 e N 1 (Typ) If ND & NE 2 are Even 2 Sawn Singulation E E2 E2 Top View (NE-1)x e (Ref) 2 b A D (Ref) ND & NE Odd C 0.08 C Symbol A A1 A3 b e N ND NE D x E BASIC D2 E2 L Min e Thermal Base D2 2 D2 Millimeters Max 0.80 1.00 0 0.05 0.20 Reference 0.18 0.30 0.50 BASIC 16 4 4 3.00 x 3.00 1.55 1.80 1.55 1.80 0.30 0.50 Ordering Information Part / Order Number Marking Shipping Packaging Package Temperature 5V41064NLG See Page 8 Trays 16-pin QFN 0 to +70° C 5V41064NLG8 Tape and Reel 16-pin QFN 0 to +70° C 5V41064NLGI Trays 16-pin QFN -40 to +85° C 5V41064NLGI8 Tape and Reel 16-pin QFN -40 to +85° C “G" after the two-letter package code are the Pb-Free configuration and are RoHS compliant. While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any IDT product for use in life support devices or critical medical instruments. IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER 10 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Revision History Rev. Originator A Date Description of Change 04/01/08 Initial release - preliminary. B RW 03/02/10 1. Updated Title and Features bullets 2. Added Differential Phase Jitter table 3. Updated Cycle-to-cycle Jitter spec from 80ps to 125ps C RDW 06/18/10 1. Updated package and pinout to 16QFN. 2. Added Spread Spectrum. D RDW 07/19/10 1. Updated title and general description 2. Updated cycle-to-cycle jitter spec from 125 to 100 ps E RDW 12/21/10 1. Minor corrections 2. Updated with Typical data 3. Released to final F RDW 10/28/11 Updated Thermal char data G RDW 11/21/11 1. Changed title to “1 Output PCIe GEN1/2 Synthesizer” 2. Added note to Features section: “For PCIe Gen3 applications, see 5V41234” 3. Updated Differential Phase Jitter table. IDT® 1 OUTPUT PCIE GEN1/2 SYNTHESIZER 11 IDT5V41064 REV G 112111 IDT5V41064 1 OUTPUT PCIE GEN1/2 SYNTHESIZER Innovate with IDT and accelerate your future networks. Contact: www.IDT.com For Sales For Tech Support 800-345-7015 408-284-8200 Fax: 408-284-2775 www.idt.com/go/clockhelp Corporate Headquarters Integrated Device Technology, Inc. www.idt.com © 2010 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT, ICS, and the IDT logo are trademarks of Integrated Device Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners. Printed in USA