ACS8944 JAM PLL Jitter Attenuating, Multiplying Phase Locked Loop for OC-12/STM-4 ADVANCED COMMUNICATIONS COMMS & SENSING FINAL EVALUATION BOARD ACS8944 JAM PLL Evaluation Board (EVB) Overview This document describes the ACS8944 JAM PLL Evaluation Board (EVB). It describes how to set-up and operate the board in order to exercise and evaluate the functionality of the ACS8944 JAM PLL. The PCB Schematic and Bill of Materials (BOM) are included. This document should be read in conjunction with the ACS8944 JAM PLL Datasheet. Revision 1/January 2007 © Semtech Corp. Page 1 www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING Table of Contents FINAL EVALUATION BOARD Section Page Overview ..................................................................................................................................................................................................... 1 Description ................................................................................................................................................................................................. 3 Features..............................................................................................................................................................................................3 Hardware Description ........................................................................................................................................................................3 PCB Description .................................................................................................................................................................................4 PCB Configuration..............................................................................................................................................................................4 PCB Layout Recommendations ........................................................................................................................................................5 Bill Of Materials ......................................................................................................................................................................................... 6 Schematic .................................................................................................................................................................................................. 7 Trademark Acknowledgements ................................................................................................................................................................ 8 Revision Status/History ............................................................................................................................................................................ 8 Abbreviations ............................................................................................................................................................................................. 8 Notes .......................................................................................................................................................................................................... 9 Ordering Information .............................................................................................................................................................................. 10 Disclaimers...................................................................................................................................................................................... 10 Contacts........................................................................................................................................................................................... 10 Revision 1/January 2007 © Semtech Corp. Page 2 www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING Description FINAL Features The ACS8944 JAM PLL Evaluation Board (EVB) provides the means to quickly set-up and evaluate the functionality and performance of the ACS8944 JAM PLL device. The ACS8944 can be configured using simple jumper settings on the EVB. The board provides differential line input and output connections via SMB connectors, with appropriate termination circuitry for LVPECL signals. The required RC components that define the loop filter bandwidth can be determined from the datasheet for the specific application. These must then be soldered to the underside of the board. EVALUATION BOARD z 4-layer populated PCB z Surface-mounted ACS8944 JAM PLL z SMB connectors for a differential clock input and differential output z Jumpers to configure input and output clock frequencies z Pushbutton switch for board reset z Single 3.3V supply connection Hardware Description Figure 1 Annotated EVB - Top View 0 V DC SK1 Terminal Block +3.3 V DC JMP1 Configuration Jumpers Decoupling Capacitor Probe Point (VDD) Probe Point (VDD) Lock Detector Probe Point (Active Low) Ref Clock Differential Input (-ve) SMB Connector IN Ref Clock Differential Output (+ve) SMB Connector Ref Clock Differential Input (+ve) SMB Connector OUT Ref Clock Differential Output (-ve) SMB Connector Probe Point (RESET Bar) Probe Point (GND) Probe Point (GND) LVPECL Input Termination Revision 1/January 2007 © Semtech Corp. U1 ACS8944 JAM PLL Page 3 SW1 RESET Switch LVPECL Output Termination F8944EVB_001annotop_01 www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING FINAL EVALUATION BOARD Figure 2 Annotated EVB - Bottom View PLL Loop Filter Components C7 (PCB) = Datasheet C2 R9 (PCB) = Datasheet R1 C8 (PCB) = Datasheet C1 C10 (PCB) = Datasheet C3 R10 (PCB) = Datasheet R2 C9 (PCB) = Datasheet C4 Note... C7 and C9 landing pads allow different sized capacitors C5, C6, C13, C14, C15, C16: 3.3 V Supply Decoupling Capacitors C11, R11: RC Delay for Reset R12, C17: Lock Detector Filter Components F8944EVB_annotbotfig2_01 PCB Description PCB Configuration Figures 1 and 2 indicate the location of the main PCB components referred to in this description. Where “Datasheet” terms are given in red in Figure 2, these refer to the loop filter components in the figures and tables in the “Loop Filter Components” section of the ACS8944 datasheet. The EVB can be configured using three jumpers on the JMP1 header block located on the top left hand corner of the evaluation board. Figure 3 Jumper Configuration EXT1 Config 6 8 10 12 14 16 18 20 1 3 5 7 9 11 13 15 17 19 F77 F155 Revision 1/January 2007 © Semtech Corp. 4 F38 The lock detector output can be observed via the test point TP1. This is located on the right hand side of the board and is labelled “LOCKB”. 2 JMP1 The configuration of the device is controlled via jumpers on the header block JMP1. The manual reset switch SW1 must be used to reset the device after a configuration change. OP_FSEL Config F19 A single 3.3 V DC supply is required for the board. This should be connected to the board via terminal SK1. A 100 uF supply decoupling capacitor is provided for the supply near to SK1. Each supply pin to the device has additional decoupling capacitors placed close to the pin. EXT2 Config EXT1 and EXT2 configure the input frequency of the ACS8944, whilst OPFSEL configures the required output frequency. The jumper connections should be configured as described in Tables 1 and 2. Page 4 www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING FINAL C9, C10, R9 and R10) should be changed to the values specified in the “Loop Filter Components” section of the ACS8944 datasheet. Table 1 Input Frequency Configuration Settings Input Frequency (MHz) EXT1 EXT2 19.44 Connect 1 & 2 Connect 9 & 10 38.88 Connect 3 & 4 Connect 11 & 12 77.76 Connect 5 & 6 Connect 9 & 10 155.52 Connect 7 & 8 Connect 11 & 12 PCB Layout Recommendations The Evaluation Board PCB layout follows good layout practice for minimizing noise. Large area ground planes and supply decoupling are used. The analog and digital parts of the IC use separate ground and supply connections. The following guidelines should be considered when laying out a custom circuit board for the ACS8944 IC: Table 2 Output Frequency Configuration Settings Output Frequency (MHz) 1. A generous ground plane should be provided around the IC to minimize noise and maximize the effectiveness of decoupling components. OP_FSEL 19.44 Connect 13 & 14 38.88 Connect 15 & 16 77.76 Connect 17 & 18 155.52 Connect 19 & 20 2. Power supply decoupling capacitors should be placed as close as possible to the pins of the IC to decouple all power connections to the device. The ACS8944 EVB board comes configured with loop filter component values for a 19.44 MHz input clock with a loop filter bandwidth of 2 kHz. For other input frequencies and loop filter bandwidths the loop filter components (C7, C8, Revision 1/January 2007 © Semtech Corp. EVALUATION BOARD 3. Ensure that for the differential inputs and outputs, both tracks in each pair of tracks are matched in length. 4. Ensure that for the differential inputs and outputs, both tracks in each pair of tracks are of 50 Ohm impedance. Page 5 www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING Bill Of Materials FINAL EVALUATION BOARD Table 3 Evaluation Board Component Listing Reference Value Description PCB Qty. C1, C2, C3, C4, C5, C14, C16, C17 220 nF 0805 Capacitor (SMD). 8 C6, C13, C15 100 pF 0603 Capacitor (SMD). 3 C7, C9 15 uF 1812 Polarized Capacitor (Surface Mount). Low ESR Electrolytic. 2 C8, C10 100 nF 0805 Capacitor (SMD). 2 C11 22 nF 0603 Capacitor (SMD). 1 C12 100 uF Case ‘D’ Polarised Capacitor (SMD). 1 JMP1 Header 10 x 2 Header, 10-Pin Dual Row 0.1. 1 R1, R3, R6, R8 82 R 0805 Resistor (SMD). 4 R2, R4, R5, R7 130 R 0805 Resistor (SMD). 4 R9, R10 75 R 0805 Resistor (SMD). 2 R11 10 K 0603 Resistor (SMD). 1 R12 470 K 0603 Resistor (SMD). 1 RF1 I- 5-Pin SMB - 90 deg. (PTH) 1.0mm Centre Hole. 1 RF2 I+ 5-Pin SMB - 90 deg. (PTH) 1.0mm Centre Hole. 1 RF3 O+ 5-Pin SMB - 90 deg. (PTH) 1.0mm Centre Hole. 1 RF4 O- 5-Pin SMB - 90 deg. (PTH) 1.0mm Centre Hole. 1 SK1 PCON2 5 mm Pitch Vertical Mount DC Connector. 1 SW1 SW SPST Push Button Single-Pole, Single-Throw Switch. 1 TP1 LOCKB Test Point. Not populated. 0 TP5 RESETB Test Point. Not populated. 0 TP6, TP8 + Test Point. Not populated. 0 TP7, TP9 - Test Point. Not populated. 0 U1 ACS8944_QFN_DUAL QFN 7 x 7 48L MLP Package Footprint. 1 Revision 1/January 2007 © Semtech Corp. Page 6 www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING Schematic FINAL EVALUATION BOARD Figure 4 EVB Schematic Revision 1/January 2007 © Semtech Corp. Page 7 www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING Abbreviations FINAL EVALUATION BOARD Semtech and the Semtech S logo are registered trademarks of Semtech Corporation. BOM Bill of Materials DC Direct Current EVB Evaluation Board I/C Integrated Circuit I/O Input/Output JAM PLL Jitter-Attenuating, Multiplying PLL LVPECL Low Voltage Positive Emitter Coupled Logic MLP Micro Leadframe Package PCB Printed Circuit Board PLL Phase Locked Loop PTH Plated Through Hole RC Resistor/Capacitor SMB Sub-Miniature type B- a connector type for use in DC to 4 GHz range Revision Status/History Trademark Acknowledgements The Revision Status, as shown in the top center of the document, may be DRAFT, PRELIMINARY, or FINAL, and refers to the status of the Device (not the document), with the design cycle. DRAFT status is used when the design is being realized but is not yet physically available, and the document content reflects the intention of the design. The document is raised to PRELIMINARY status when initial prototype devices are physically available, and the document content more accurately represents the realization of the design. The document is only raised to FINAL status after the device has been fully characterized. This is a FINAL release (Revision 1) of the ACS8944 EVB document. Changes made for this document revision are given in Table 4, together with a brief summary of previous revisions. For specific changes between earlier revisions, refer (where available) to those earlier revisions. Always use the current version of the document. Table 4 Revision History Revision Rev. 1, January 2007 Reference All pages Revision 1/January 2007 © Semtech Corp. Description of changes Initial draft. Page 8 www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING Notes Revision 1/January 2007 © Semtech Corp. FINAL Page 9 EVALUATION BOARD www.semtech.com ACS8944 JAM PLL ADVANCED COMMS & SENSING Ordering Information FINAL EVALUATION BOARD Table 5 Parts List Part Number ACS8944 EVB Description Evaluation Board (EVB). Disclaimers Life support- This product is not designed or intended for use in life support equipment, devices or systems, or other critical applications. This product is not authorized or warranted by Semtech for such use. Right to change- Semtech Corporation reserves the right to make changes, without notice, to this product. Customers are advised to obtain the latest version of the relevant information before placing orders. Compliance to relevant standards- Operation of this device is subject to the User’s implementation and design practices. It is the responsibility of the User to ensure equipment using this device is compliant to any relevant standards. Contacts For Additional Information, contact the following: Semtech Corporation Advanced Communications Products E-mail: [email protected] [email protected] Internet: http://www.semtech.com USA: 200 Flynn Road, Camarillo, CA 93012-8790 Tel: +1 805 498 2111, Fax: +1 805 498 3804 FAR EAST: 12F No. 89 Sec. 5, Nanking E. Road, Taipei, 105, TWN, R.O.C. Tel: 886-2-2748-3380 Fax: 886-2-2748-3390. EUROPE: Semtech Ltd., Units 2 and 3, Park Court, Premier Way, Abbey Park Industrial Estate, Romsey, Hampshire, SO51 9DN Tel: +44 (0)1794 527 600 Fax: +44 (0)1794 527 601 ISO9001 CERTIFIED Revision 1/January 2007 © Semtech Corp. Page 10 www.semtech.com